,1'i !I'-illH1 Mi K.lW H, h ,,!!!!i\ If'' «/.-. • j'I.i!iif|i liiii KM <(,,- ,11 I I! !!!!»! I'm ■:;.:lj"! ■!:'-■■* i li Hl!!"tf|. l|i:!lili!|Hiii.r 1 'Irdl.li. I '":;i:i!.iii mk M iiitii £ ft' i $ ■:■ w DZ^QCO0Q'^^OO6^QOOtyDcO:C 15 Surgeon General's Office n lh No. /^ <£j2/^y U) &.-,. .,-™________........_.(I a^O(X}gjg^a^aoo CONTENTS. XV11 CHAPTER V. Copper, ...... Section 1. Detection of Copper in Organic Mixtures, 2. Detection of Copper in the Tissues, 3. Quantitative Determination of Copper, PAGE 253 253 255 255 CHAPTER VI. Detection of Zinc in Organic Mixtures and in the Tissues, . 256 CHAPTER VII. Iodine, ....... 257 Section 1. Detection of Uncombiued Iodine in Organic Mix- tures, &c, . . . • • 251 2. Detection of Iodide of Potassium in Organic Mix- tures, &c, ..... 258 CHAPTER VIII. Sulphuric Acid, ....••• 258 Section 1. Detection of Sulphuric Acid in Organic Mix- tures, . 2,)8 2. Detection of Sulphuric Acid in Stains on Clothing, 260 3. Detection of Sulphate of Indigo in Organic Mix- tures, &c, . . • • 260 4. Quantitative Determination of Sulphuric Acid, . 261 CHAPTER IX. Hydrochloric Acid, 261 Section 1. Detection of Hydrochloric Acid in Organic Mix- tures, &c, ..... 261 2. Quantitative Determination of Hydrochloric Acid, 263 CHAPTER X. Nitric Acid, ...••■ Section 1. Detection of Nitric Acid in Organic Mixtures, 2. Detection of Nitric Acid in Stains on Clothing, 2C3 263 265 win CONTENTS. CHAPTER XL PAUE Oxalic Acid, ....... 265 Section 1. Detection of Oxalic Acid in Organic Mixtures, . 265 2. Quantitative Determination of Oxalic Acid, . 267 CHAPTER XII. Hydrocyanic (or Prussic) Acid, .... 267 Section 1. Detection of Hydrocyanic Acid in Organic Mix- tures, ..... 268 2. Quantitative Determination of Hydrocyanic Acid, 271 CHAPTER XIII. Opium, . . . . . . . .271 CHAPTER XIV. Method of Examining an Organic Mixture, suspected to con- tain some Mineral Poison, the Nature of which is un- known, ....... 274 Weights and Measures, . . . . . .277 Index, ....... 279 LIST OF ILLUSTRATIONS. FIGURE 1. Oxalate of Urea, 2. Nitrate of Urea, . . . . 3. Uric Acid, .... 4. Hippuric Acid, .... 5. Mucus and Epithelium, 6. Evaporated Residue of Healthy L'rine, 7. Mixed Phosphates, 8. Prismatic Crystals of Triple Phosphate, . 9. Penniform Crystals of Triple Phosphate, 10. Stellate Crystals of Triple Phosphate, 11. Urate of Ammonia, 12. Urate of Ammonia with Spiculaj, 13. Urate of Soda, 14. Fermentation Test for Sugar, 15. Torula Vesicles, 16. Torula Stem, . 17. Fibrinous Cast, 18. Blood in Urine, 19. Pus in Urine, .... 20. Large Organic Globules, . 21. Small Organic Globules, XX ILLUSTRATIONS. FIGURE 22. Spermatozoa and Spermatic Granules, 23. Octohedra of Oxalate of Lime, 24. Octohedra of Oxalate of Lime seen when dry 25. Dumb-bells of Oxalate of Lime, 26. Rosettes of Cystine, 27. Hexagonal Crystals of Cystine, 28. Chloride of Sodium simulating Cystine, . 29. Nitrate of Urea, . . . . 30. Crystalline Forms of Uric Acid, . 31. Crystalline Forms of Uric Acid, 32. Chloride of Sodium, 33. Hippuric Acid, .... 34. Mixed Phosphates, 35. Pus-Corpuscles, ... 36. Urinometer, .... 37. Triple Phosphate (Stella), 38. Triple Phosphate (Prismatic), 39. Crystalline Forms of Uric Acid, 40. Octohedra of Oxalate of Lime, 41. Dumb-bells of Oxalate of Lime, 42. Rosettes of Cystine, 43. Hexagonal Plates of Cystine, 44. Urate of Soda, .... 45. Fat in Urine, ..... 46. Mucus and Epithelium, 47. Pus in Urine, ..... 48. Blood in Urine, .... 49. Spermatozoa, &c, ILLUSTRATIONS. XXI FIGURE PAGE 50. Apparatus for the Estimation of Sugar in Urine, 121 51. Alternating Calculus, .... . 132 52. Uric Acid Calculus, .... 132 53. Urate of Ammonia Calculus, .... . 134 54. Phosphate of Lime Calculus, 134 55. Fusible Calculus, ..... . 136 56. Oxalate of Lime Calculus, ... 137 57. Biliary Calculi, .'.... . 143 58. Cholesterin, ..... 144 59. Blood Corpuscles in strings, .... . 150 60. Blood Corpuscles detached, 150 61. Blood Corpuscles collapsed, .... . 151 62. White Corpuscles of the Blood, . 153 63. Fat in Blood, ..••■• . 187 64. Cholesterin, . . . . • 188 65. Milk Globules, ..... . 199 66. Colostrum Corpuscles, .... 199 67. Pus in Milk, ...... . 205 68. Blood in Milk, 205 69. Starch Granules, . . 207 70. Pus-Corpuscles, . 2-13 71. Apparatus for the Estimation of Carbonic Acid, . 221 72. Arsenious Acid, ..... 234 73. Crust of Reduced Arsenic, . . 234 74. Apparatus for Marsh's Test, 236 75. Apparatus for Marsh's Test, . . 236 i I The symbols employed throughout the work are those now in com- mon use among chemists. Substances in the solid state are represented by strong Roman type, as As03, arsenious acid ; liquids, and substances in solution, are printed in italics, as HO, water, GJI^O,HO, alcohol; and gases, in thin hair letters, as H, hydrogen, C02, carbonic acid. These symbols, and the method of using them, are fully described in my " Introduction to Practical Chemistry," pp. xviii-xxiii. MEDICAL CHEMISTRY. PART I. CHAPTER I. HEALTHY URINE. SECTION I. 1. Healthy human urine is an amber-colored, watery fluid, holding in solution a great variety of substances, both organic and inorganic, and containing also in suspension a small quantity of mucus, derived from the bladder and uri- nary passages. The specific gravity (278) of the healthy secretion may be said to vary from 1003 to 1030, depend- ing on the amount of solid and liquid food taken, the period of the day at which it is passed, or other circumstances, which tend to increase or diminish the proportion of solid matter contained in it. Thus the urine which is passed shortly after drinking much water or other fluid, commonly called urina potus, is usually pale in color, and of low spe- cific gravity, varying from 1003 to 1009; while, on the other hand, that which is secreted soon after the digestion of a full meal, commonly called urina chyli, has most com- monly a high specific gravity, frequently 1030; the urine which is passed immediately after a night's rest, called urina sanguinis, may generally be considered to furnish a fair specimen of the average density of the whole urine, and will in most cases be found to have a specific gravity vary- ing from 1015 to 1025. The average density of the whole 3 26 healthy urine. urine passed by an individual in the twenty-four hours, is usually from 1015 to 1020; and the quantity passed during the same period varies from twenty to forty-eight or fifty ounces, holding in solution usually from 600 to 700 grains of solid matter (279). 2. While warm, urine has a slightly aromatic smell, which is not perceptible after cooling. It is usually slightly acid to test paper, but the experiments of Dr. Bence Jones show that when passed shortly after eating, the urine is often neutral, or even alkaline, becoming again gradually more and more acid, up to the time when the next meal is taken. When kept for some little time, it gradually becomes turbid, and deposits a sediment of earthy phosphates, previously held in solution by the slight excess of acid present (43). If the urine be kept for a still longer time, it gradually putre- fies, and, becoming more and more concentrated by sponta- neous evaporation, deposits minute crystals of chloride of sodium, phosphates, and other salts, and eventually becomes covered with a grayish-colored mould. 3. Although chemists have not yet succeeded in insulat- ing for examination all the ingredients of urine, nor even ascertained the general nature and character of several of the compounds which probably enter into its composition, still they have by their researches determined what appear to be the most important of its constituents; and it is to these only that the student need turn his attention, leaving the more problematical and obscure parts of the subject to be decided by the future labors of the physiological chemist. 4. The solid matters of the urine may be said to consist of the following—viz., Urea ; uric acid ; hippuric acid ; vesical mucus and epithelial debris; animal extractive; ammoniucal salts ; fixed alkaline salts; and earthy salts. 5. The student will do well to test a little of the healthy secretion, which would, for this purpose, be that passed immediately after a night's rest (1), for these several sub- stances, in the manner described under each, in the follow- ing sections; and if he has leisure and opportunity, he may prepare specimens of urea, uric and hippuric acids, and some of the other constituents. UREA. 27 SECTION II. Urea (CJI4N,02). 6. This important ingredient of the urine, which appears to be the vehicle by which nearly the whole of the nitrogen of the exhausted tissues of the body is removed from the system, is a solid crystalline substance, colorless when in a state of purity, and easily insulated from the other mat- ters with which it is associated. 7. The presence of urea in the urine may be readily shown by concentrating a little of the secretion to about one-half or one-third its bulk, and mixing it with an equal quantity of pure nitric acid ; when delicate crystalline rhom- boidal plates of impure nitrate of urea (C2H4N202,HO,N06) will be found gradually to separate from the liquid (16). 8. Pure urea may be obtained from the urine, by first converting it into the oxalate (C.JI4N202,I10,C203) (14), the crystals of which should be dissolved in hot water; after which the solution is treated with pounded chalk (CaO,C02) as long as effervescence is produced. The oxalic acid (C203) is thus removed from the urea, which latter remains^ in solution, while the insoluble oxalate of lime (CaO,C203+2Aq), together with the excess of chalk em- ployed, is precipitated. Oxalate of urea. Carb.lime. Oxal. lime. _____________A______________^ ____A-----^ f-------A-------( C!1//1A'z02>7ZO,Ci,03+CaO,CO:r=CaO,C203+COg + Urea. IIO + CJIiN.,Or The aqueous solution may then be purified by boiling with animal charcoal, and carefully evaporated at a gentle heat on a water bath, or under the receiver of the air-pump,1 until the urea crystallizes. 9. The crystals of urea, which, when obtained by slow evaporation, are four-sided prisms, are soluble in about their own weight of cold water, and in a much smaller quantity of hot; from which latter the urea separates -on cooling, in the form of beautiful silky needles. It is soluble in about 1 Sec Introduction to Practical Chemistry, second edition, p. 194. 28 healthy urine. 4-5 parts of cold'alcohol, and in less than half that quan- tity of hot; in cold ether it is nearly insoluble. Its taste is saline and cooling, somewhat resembling that of nitre. 10. The proportion of urea present in healthy urine ap- pears to vary from twelve to upwards of thirty parts in 1000, about fourteen or fifteen being the average. 11. An aqueous solution of urea may be kept, provided it is pure and tolerably concentrated, for a considerable length of time, without undergoing chemical change; but if any albumen or mucus, or other fermentescible matter, is present, decomposition rapidly sets in, and in a short time the whole of the urea becomes transformed into car- bonate of ammonia {NH^O^O^, the elements of water being at the same time assimilated. C.1HiN.lOi + UIO=2(NHiO, C02) In urine this change speedily takes place, owing to the presence of mucus; the secretion thus acquiring, especially in warm weather, an alkaline reaction in the course of a few hours after being passed. Under the influence of the caustic alkalies also, urea becomes gradually converted into carbonate of ammonia. 12. When heated on platinum foil to about 250°, urea fuses without undergoing decomposition ; but if the heat be increased much beyond that point, it is decomposed into ammonia (NH3) and cyanate of ammonia (NH4°)G2NO), which volatilize, leaving a residue consisting chiefly of cya- nuric acid (3HO,Cy303). 13. Urea, though its solution is neutral to test paper, has decidedly basic characters, combining with acids to form salts, some of which are crystalline. Of these, the two which are of the most practical importance, are the oxalate (C2H4N202,HO,C203) and the nitrate (C2H4N202,HO,N05), which, on account of their sparing solubility in water, supply a ready means of separating urea from the other matters co-existing in the urine. 14. Oxalate of urea (C2H4N202,HO,C203) may be pre- pared by concentrating urine on a water bath to about one- eighth its bulk, and filtering through muslin, in order to separate the insoluble sediments of phosphates and urates, which are gradually deposited during the evaporation. The UREA. 29 Oxalate of Urea. liquid thus clarified, is mixed with about an equal bulk of a strong solution of oxalic acid in hot water, or the solid acid in powder may be added as long as the liquid, heated to about 190° or 200°, continues to dissolve it. The mix- ture, on cooling, deposits an abundant crop of crystals of oxalate of urea, mixed with a little of the excess of oxalic acid, and colored brown by the adhering impurities. The crystals are then gently pressed between folds of filtering paper, washed with a small quantity of ice-cold water, and purified by recrystallization : the last traces of coloring matter being removed, if necessary, by boiling the solution with animal char- coal. 15. The oxalate thus obtained is colorless, and in the form of tabular or prismatic crystals (Fig. 1), which are readily soluble in hot water, but only sparingly so in cold, twenty-five parts of which dissolve not more than one part of the salt. 16. Nitrate of urea (C2H4N202,HO,N05) may be obtained by adding strong colorless nitric acid, free from nitrous acid, to urine previously concentrated by evaporation to about one-third its bulk ; the nitrate gra- dually separates in irregular rhom- boidal plates (Fig. 2), more or less colored and modified in form, by the impurities present. The crystals are washed with a little ice-cold water, then pressed between folds of filter- ing paper, and redissolved in luke- Avarm water; lastly, they are puri- fied by recrystallization, and if ne- cessary, the last traces of coloring matter may be removed by boiling the solution with animal charcoal. 17. Nitrate of urea is soluble in about eight times its weight of cold water, and in a much smaller quan- tity of hot. It is tolerably soluble also in alcohol, espe- cially when warm; but almost insoluble in ether. 3* Fig. 2. Nitrate of Urea. 30 II E A L T H Y U R I X E. 18. The formation of this crystalline compound on the addition of nitric acid, is one of the most distinctive tests for the presence of urea which we possess. The experiment is made easily, and with great delicacy, under the microscope, by concentrating a drop or two of urine on a glass slide, and adding to it about an equal quantity of pure nitric acid ; the nitrate will gradually crystallize in delicate rhomboidal plates (Fig. 2), the number and abundance of which will furnish some indication of the quantity of urea present in the secretion (181). SECTION III. Uric (or Lithic) Acid (C^N^H^O^). 19. Uric acid, though usually present only in small quan- tity in human urine, appears to be one of the most impor- tant of its ingredients; and as the proportion varies consi- derably in many forms of disease, its determination, when in abnormal quantity, frequently affords much valuable as- sistance to the physician in diagnosis. The proportion pre- sent in the healthy secretion appears to vary from 0*3 to nearly 1*0 in 1000 parts, about 0-4 being the usual average. It probably exists for the most part in combination with ammonia, since, when uncombined, it requires nearly 15,000 times its weight of cold water to dissolve it, while the urate of ammonia (NH4O,C10N4H4Oc) is considerably more soluble (22). 20. Uric acid may be obtained by adding to urine, pre- viously concentrated to about half its Elg- 3- bulk, a few drops of hydrochloric acid (HCl), and allowing the mixture to stand for a few hours in a cool place. Minute reddish crystals of the acid gra- dually appear, having the forms shown in figure 3, stained with the coloring ^L matters coexisting in the urine. These "f2jj Cb q crystals may then be dissolved in mode- unc Acid. rately dilute potash, and from the solu- tion thus obtained, the pure acid may be again precipitated in a crystalline colorless state, by supersaturating it with hydrochloric acid. U R I C (0 It LI T IIIC) A C I D. 31 21. The crystalline forms in which uric acid is presented to us are very various (186), but they all appear to be mo- difications of the rhombic prism. Most of these crystals, when examined with the polarizing microscope, develope very beautiful colors; and their forms are frequently cha- racteristic, and indicative of the peculiar circumstances under which they may have been deposited. 22. Uric acid requires, according to Liebig, about 15,000 times its weight of cold, and nearly 2,000 times it weight of hot, water, to dissolve it, forming, in the latter, a solu- tion which is feebly acid to test paper. It is insoluble in alcohol, and nearly so in dilute hydrochloric and sulphuric acids ; it dissolves in the latter acid when concentrated, and is reprecipitated on the addition of water. It combines with bases, especially the alkalies and alkaline earths, forming salts (urates) which are for the most part insoluble, or very sparingly soluble in Avater. Of these the most soluble is the urate of potash (KO,C10N4H4Oc), which dis- solves in about 85 times its weight of hot water, and in a still smaller quantity if any free potash is present. On this account, uric acid dissolves with comparative facility in a solution of potash. Urate of soda (NaO,Ci0N4H4O6) re- quires for its solution 124 times its weight of hot water; and urate of ammonia (NH4O,C10N4H4O6) 243 times its weight of hot, and about 1720 of cold, water, to effect its solution. The presence of a small quantity of chloride of sodium, such as is contained in the urine, renders Avater capable of dissolving nearly tAvice as much urate of ammonia as is taken up by pure Avater. 23. The action of nitric acid (iV"C\) upon uric acid is highly characteristic, and furnishes, perhaps, the most deli- cate test of its presence Avhich we possess. If a little of the acid, in the state of poAvder, is placed in a drop or two of tolerably strong nitric acid, in a watch-glass or on a strip of glass, it will gradually dissolve ; carbonic acid (co2) and nitrogen being given off Avith effervescence, and leaving behind a mixture of alloxan (C^.^O^, alloxantine (C4iT3 JST,03), and some other compounds. This may then be evaporated nearly to dryness at a gentle heat, when a red residue will be left, Avhich, when cold, should be moistened Avith a drop or tAVO of ammonia, or exposed to ammoniacal HEALTHY URINE. fumes, Avhich will develope a beautiful purple color, owing to the formation of murexide {Ol2NbII60^. The same effect is produced when urate of ammonia, or any other urate, is similarly treated. 24. When heated before the blowpipe, uric acid is decom- posed, emitting a disagreeable smell, resembling that of burnt feathers, mixed Avith that of hydrocyanic acid (840), which, together with carbonate of ammonia and some other compounds, is formed during the decomposition. SECTION IV. Hippuric Acid (HO,C18NH805). 25. A small quantity of hippuric acid appears to be gene- rally present in healthy urine, and in certain forms of dis- ease, especially in cases where a vegetable diet has been adopted, the quantity is found to increase considerably. 26. Hippuric acid may be prepared from fresh human urine, or still more readily from the urine of the herbivora, which usually contains it in much larger quantity than the human secretion. The urine is first evaporated at a gentle heat until it has the consistence of a syrup ; it is then, after cooling, supersaturated with hydrochloric acid, which will dissohre the earthy salts, and cause at the same time a crystalline precipitate of impure hippuric acid mixed with coloring matters and other substances, which give it a more or less dark brown or reddish color. The precipitate is then dissolved in a small quantity of hot Avater, from which it again crystallizes on cooling. The crystals, thus to a certain extent purified, are now dissolved in hot water, and a current of chlorine gas is passed through the hot solution, which has the effect of decomposing most of the coloring matter and other impurities, leaving the hippuric acid unaffected. The acid liquid is then neutralized with car- bonate of soda, by which hippurate of soda (iVa0,C18iVi^O.) is formed, the carbonic acid being given off Avith efferves- cence. The solution is now boiled with animal charcoal, in order to remove the last traces of coloring matter. The solution of hippurate of soda is filtered, and supersaturated with hydrochloric acid, which precipitates pure hippuric acid in the form of minute tufts of needle-shaped crystals HIPPURIC ACID. 33 (Fig. 4, a & b); these may be again dissolved in hot water, and allowed to cool gradually, when beautiful crystals Fig. 4. Hippuric Acid. (four-sided prisms) will be obtained, of considerable length, but so friable as to fall into powder under the slightest pressure. 27. Hippuric acid is very sparingly soluble in cold water, requiring about 400 times its weight of liquid to dis- solve it; in hot water, however, it is readily soluble, and on cooling, crystallizes in beautiful silky tufts. It is very soluble in alcohol, and tolerably so in ether. 28. When mixed with uric acid, it may be separated from that substance by treating the mixture either with hot water or alcohol, in both of which uric acid is insoluble or nearly so (22). It may be distinguished from uric acid also, by its giving no purple color when tested with nitric acid and ammonia (23), and by its different crystalline form (2(5, 29, 186). 29. When an alcoholic solution of hippuric acid is al- lowed to evaporate slowly, the crystalline residue which is left has usually some such appearance as that shown in figure 4, c. When deposited from a hot aqueous solution, the crystals have more the appearance shown at d, in the figure. # # . . 30 When heated in a tube, it is converted chiefly into benzoic acid (HO, CuH503) and benzoate of ammonia (NlliO, CuH60,), which sublime, together with a red, oily matter, which has a peculiar and characteristic smell, re- sembling that of the Tonka bean. Nitric acid converts hippuric acid into benzoic acid, as does also hot sulphuric acid ; sulphurous acid (S02) being in the latter case evolved. 34 HEALTHY URINE. ' SECTION V. Vesical Mucus and Epithelial Scales. 31. The small traces of mucus and epithelial debris, which are always present in urine, and Avhich do not gene- rally amount to more than from 0-1 to 0-3 in 1000 parts of the healthy secretion, are derived from the internal surface of the bladder and urinary passages. The quantity is so small as to be scarcely visible in healthy urine, until, after standing a short time, it has subsided, in the form of a thin cloud, to the bottom of the liquid. It may be separated by passing the urine through a filter, on the sides of which it will be deposited in the form of a shining pellicle. 32. When examined under the lg' ' microscope, mucus is found to @ 'J0ify /-gx consist of minute granular cor- ^ %® puscles (Fig. 5, a) floating in the •ilS: J|| fluid, which are colorless, or nearly so, more or less round, and frequently oval in shape, and usually accompanied by epi- thelial scales. The mucus cor- puscles dissolve when treated with strong nitric and acetic MucUS corpuscle* »d Scales of Epi- acids, forming a solution from theiium. Magnified 200 diame- which ferrocyanide of potassium tcrs. *" A throAvs down a white precipitate. 33. When treated with dilute acetic acid [110,0^1^0^, these corpuscles become more transparent, lose their granu- lar appearance, and show in the interior one or more distinct nuclei (662). The corpuscles are unaffected, or nearly so, by the dilute mineral acids, but readily dissolve in a solu- tion of potash, with the evolution of ammoniacal fumes. For the further characters of mucus see paragraphs 99,153, 210, 247, 660, &c. 34. The epithelial scales found in the urine, associated with mucus, and derived from the epithelial covering of the organs through which the secretion has passed, are usually more or less torn and broken (Fig. 5), but are occasionally met with uninjured, when they have the appearance shoAvn at b in the figure. EXTRACTIVE MATTER--AMMONIACAL SALTS. 35 SECTION VI. Extractive Matter. 35. Under the name of extractive matter, or animal ex- tract, may be included all the uncrystallizable organic mat- ters found in the residue of evaporated urine, which are soluble either in water or alcohol, including two substances which will probably be found to possess considerable physio- logical interest—viz., kreatine (C8N3Hn06) and kreatinine (C8N3H702),1 and also the peculiar yellow coloring matter of the urine, of which indeed it appears mainly to consist; in other words, the extractive matter may be said to com- prise all the combustible portion of the residue, with the exception of the urea, uric acid, vesical mucus, and ammo- niacal salts. 36. These extractive matters, which in healthy urine usually amount to from seven to twelve parts in 1000, are sometimes divided into spirit or alcohol extract, including the portion soluble both in water and alcohol, Avhich has also been called osmazome ; and water extract, including that which is soluble in Avater and insoluble in alcohol. The real nature of these matters is still very imperfectly understood; and until Ave shall have obtained further insight into them and their connection with the animal functions, the student may consider them as so much undefined matter, excreted from the body ; without Avaiting to inquire whether lactic acid and other compounds, the presence of which may be considered as uncertain, are or are not contained in it. SECTION VII. Ammoniacal Salts. 37. These appear to consist chiefly of the muriate {Nil,01) and the urate (NE^C^N^O,), though it is probable that some of the ammonia contained in the urme is in combination with the two other acids also present—viz., the sulphuric and phosphoric. The urate of ammonia, which has been already noticed (19), appearsto be the form in Avhich the uric acid present in the urine is for the most 1 See Liebig's Researches on the Chemistry of Food. 36 HEALTHY URINE. part held in solution, since the free acid requires for its so- lution a larger proportion of water than the secretion usually contains. 38. The presence of ammonia in urine is best shown by adding a little caustic baryta (BaOjHO)1 to the residue left after evaporating the liquid nearly to dryness at a gentle heat, when the odor of ammonia will be perceptible, and a rod moistened Avith dilute hydrochloric acid, held over it, will give rise to the characteristic white fumes of muriate of ammonia.2 The proportion of ammonia contained in healthy urine appears to be very small; in some forms of disease, hoAve\'er, especially in certain kinds of fever, the quantity is found to increase considerably. SECTION VIII. Fixed Alkaline Sal^s. 39. The fixed salts present in the urine may be obtained by incinerating the evaporated residue, when a white ash Avill be left, consisting of a mixture of the alkaline and earthy salts ; the former may then be separated from the latter by dissohdng in water, in which the earthy salts are insoluble ^ ©,* 40. The alkaline salts, which ^ in the healthy secretion usu- ^^0""i^\K^.^^/0'0 aMy amount to from thirteen J'i^KjT- sn^f.\ v."" to fourteen parts in 1000, E^„°^A/W% |- «i°7^jf.°°0 consist of sulphates of potash •' (>'.V ^: • :Cj; and soda (KO,SO,) and (Na l^Jy 0,£6>3), chloride of sodium (NaOl), chloride of potassium [KOI), and phosphate of soda Evaporated Residue of Healthy Urine. \^JSaO, HO, 1 0^2-iAq). The crystalline residue left after slowly evaporating a few drops on a piece of glass, usually has the appearance represented in Fig. 6. The 1 Baryta is here to be used in preference to potash, since the latter would cause the evolution of ammonia by its action upon the urea, which in presence of the alkalies, is converted into carbonate of ammonia (11). 2 See Introduction to Practical Chemistry, second edition, p. 76. FIXED ALKALINE SALTS. 37 crosslets (a) consist of chloride of sodium, and the more plu- mose crystals (b) are probably phosphate of soda. 41. The presence of these several salts may be shown by adding to the aqueous solution of the ash, or to the urine, the folloAving tests: (a) Nitrate of silver (AgO,N05) throws down a whitish precipitate, consisting of a mixture of chloride (AgCl) and phosphate (3AgO,P05) of silver. These may be separated from each other by warming the precipitate Avith a little nitric acid, Avhen the phosphate will dissolve, leaving the insoluble chloride, Avhich may then be tested with ammonia, in Avhich it is readily soluble. (6) The acid solution separated from the chloride (a) must now be cautiously neutralized with ammonia, which will throw down a pale yellow precipitate of phosphate (3AgO, P05), Avhich may be again dissolved by adding a slight ex- cess of nitric acid. (c) Chloride of barium (Bad), or nitrate of baryta (BaO,N05) throAvs doAvn a white precipitate of sulphate of baryta (BaO,S03), mixed with phosphate of baryta (2BaO, HO,P05); which latter may be separated by digestion in nitric acid, Avhich leaves the sulphate undissolved, proving the presence of sulphuric acid. If the nitric acid solu- tion of the phosphate be neutralized Avith ammonia, the phos- phate of baryta is again precipitated. (d) The absence of all bases except the alkalies, may be proved by testing the solution with hydrosulphate of am- monia (NH&HS) and carbonate of soda (NaO,C02), neither of which will be found to cause any precipitate (Prac. Chan. 179). (e) Potash may be shown to be present by adding to a little of the strong solution about an equal quantity of bi- chloride of platinum (PtCl2), which will cause a yellow precipitate of the double chloride of platinum and potassium, (KC1, PtCl2); and another portion may be tested with solu- tion of tartaric acid, which will throw down a white crystal- line precipitate of the bitartrate (KO,HO,C8H4O10). (/) Soda may be identified by the behaATior of the saline solution Avith antimoniate of potash, Avith Avhich it causes a white crystalline precipitate of antimoniate of soda (NaO, SbO.); and bv the mixture Avith bichloride of platinum (e) l 38 HEALTHY URINE. yielding, Avhen slowly evaporated, yelloAV needle-shaped crystals of the double chloride of sodium and platinum (NaCl,PtCl2). 42. It is difficult to say in what exact state of combina- tion these several bases and acids exist in the urine; but it is most probable that each base is divided among the several acids, and that a portion of each of the acids is combined Avith some of each of the fixed bases, and also of the am- monia (37, 40). SECTION IX. Earthy Salts. 43. The earthy salts, which form the insoluble portion of the ash, and Avhich usually amount in healthy urine to about one part in 1000, consist of the phosphates of lime and magnesia, together Avith a small trace of silica. These earthy phosphates, which are insoluble in water, appear to be retained in solution in the urine by the small excess of acid (probably phosphoric) usually present in the healthy secretion, and may be immediately precipitated from it by supersaturating with ammonia. The precipitate thus formed consists of a mixture of phosphate of lime (8CaO,3P05), and the double phosphate of ammonia and magnesia (2MgO,NH40,P05 +12 Aq), which is also called tri- ple phosphate. If this precipi- tate be examined under the micro- scope it will generally be found to consist of minute crystals of the triple phosphate, mixed with amor- phous particles of phosphate of lime (Fig. 7). 44. The crystalline form of the triple phosphate, as well as its chemical composition, depends upon the quantity of ammonia present in the liquid during its formation. When the urine is cautiously neutralized with the alkali, the crystals are prismatic (Fig. 8), and in a few rare cases, penniform (Fig. 9), and appear to consist of (MgO, NH40, HO,P05); while, if a decided excess of ammonia be added, Fig. 7. Mixed Phosphates. EARTHY SALTS. 39 the crystals are star-like and foliaceous, as shown in Fig. 10, and then consist of (2MgO,NH40,P05+12Aq). When the Fig. 8. Prismatic Crystals of Triple Phosphate. TriPle I'hospbate. urine gradually becomes alkaline, owing to the spontaneous formation of ammonia from the urea (11), the triple phos- phate is precipitated in the prismatic form, crystals of which are always to be detected in stale urine. Fig. 10. Stellate Crystals of Triple Phosphate. 45. Both varieties of triple phosphate will be found to develope beautiful colors when examined with polarized light. . 46. The presence of phosphoric acid, in combination with lime and magnesia, together with a trace of silica, in the insoluble portion of the ash, may be shown by digest- in" a considerable quantity of the latter in dilute nitric acTd, and filtering the solution from the insoluble residue. This insoluble portion, the amount of which is usually very small, may then be washed, and tested for silica, by fusion 40 HEALTHY URINE. before the bloAvpipe Avith carbonate of soda, with Avhich it Avill form, when pure, a clear colorless bead (I'rac. Client. 447). 47. The acid solution of the phosphates, filtered from the silica, may then be divided into two portions, and tested as follows: (a) To the first, add a feAv drops of a solution of nitrate of silver, and cautiously neutralize with ammonia. The yellow phosphate of silver (3AgO,P05) will be thrown down, proving the presence of phosphoric acid. (6) The second portion of the acid solution is now to be nearly neutralized with ammonia, and treated with oxalate of ammonia (NHiO,020^) as long as it causes a precipitate, in order to separate the lime, which is thrown doAvn as oxa- late (CaO, C203+2Aq). (c) The mixture (b) is boiled, and filtered from the oxa- late of lime; after which the clear solution is treated Avith a decided excess of ammonia, which will, in a short time, cause a deposition of the crystalline double phosphate of ammonia and magnesia, thus proving the presence of the latter base.1 48. The same experiments (a, b, & c) may also be made upon the phosphates which are thrown down by the addition of ammonia to fresh urine. 49. The earthy phosphates may also be distinguished by the folloAving peculiarities, Avhich may be readily seen either with or without the assistance of the microscope. (a) When present in excess, they may frequently be pre- cipitated from the urine in an amorphous form, by boiling, thus behaving like albumen (139). The phosphatic deposit may be readily distinguished from the latter, by being solu- ble in a feAv drops of nitric acid, and in not being repreci- pitated by any excess of that reagent (140). (b) The earthy phosphates are readily soluble, without effervescence, in dilute acids, such as the hydrochloric, nitric and acetic; and are reprecipitated by neutralizing the acid solution with ammonia; that of lime being amorphous and the triple phosphate in a crystalline form, either prismatic or stellate (43). 1 See Introduction to Practical Chemistry, second edition, p. 79. analysis of healthy urine. 41 (c) They are insoluble in a solution of potash. The triple phosphate, when warmed with an excess of the alkali, gives off ammoniacal fumes, which may be detected by the smell, and by the white cloud formed, when a rod moistened with dilute hydrochloric acid, is held at the mouth of the tube. 2MgO,NH40,P05+2(ifO,#0)=2(MgO,HO)+NH3 +2K0,H0,P05. (d) When heated before the blowpipe, phosphate of lime experiences little or no change, unless the heat be very in- tense, and continued for a long time, when it sometimes par- tially fuses. The triple phosphate, when heated, gives off ammonia and water; and the residual phosphate of magnesia (2MgO,P05) fuses considerably more readily than the phos- phate of lime. When the two phosphates are mixed in about equal proportion, they resemble in composition the fusible calculus, and fuse with extreme facility before the bloAvpipe (392). CHAPTER II. quantitative analysis of healthy urine. 50. Counterpoise or weigh two Berlin porcelain evapo- rating basins, which, for the sake of distinction, may be marked A and B, each capable of holding about four ounces of water; and retain the counterpoises, marking them, in order to avoid confusion. Then weigh into each of the basins, 1000 grains of urine, and allow them to evaporate first on the water bath, and afterwards in a hot-water oven, or chloride of calcium bath,1 until they cease to lose weight when weighed at intervals of an hour or tAvo. (While the evaporation is going on, the experiments described in para- graphs 59, 66, &c, may be proceeded with. The specific gra- vity also may be determined (278), and the action of the urine on test paper ascertained (277).) Then accurately Aveigh them, and if the weights of both residues agree with each other, the loss experienced during evaporation will represent the exact quantity of water contained in the » Ibid. pp. 184, 194. 4* 42 QUANTITATIVE analysis of urine. If the weights do not agree, it is probable that the desiccation of at least one of the portions has been incom- plete ; in Avhich case it is better to continue the heat a short time longer, until the results agree more closely. 51. The residue A may be first examined, retaining B for subsequent examination (62). 52. Warm the residue A Avith half an ounce or an ounce of alcohol of specific gravity about. *833, stirring the mix- ture occasionally Avith a glass rod. Pour off the solution into another basin, and again warm the residue with a little more alcohol, fresh portions of which must be added until it ceases to dissolve anything more. Whether this is the case, may be known by evaporating a drop of the clear liquid on platinum foil or a slip of glass, Avhen, if anything has been dissolved, it will be left behind as a residue. The alcoholic solution, which will contain the whole of the urea, contaminated with extractive matter and other impurities, is now to be evaporated to dryness on a water bath, retain- ing the residue which proved insoluble in the alcohol for subsequent examination (57). 53. The residue, containing the urea, left after evaporat- ing the alcoholic solution (52), is noAv to be dissolved in as small a quantity as possible of lukewarm Avater, and mixed with pounded oxalic acid (HO,C203+3Aq), Avhich may be added as long as the liquid, heated to about 190° or 200°, continues to dissolve it (14). The urea is thus converted into the oxalate {0^11^,110,0^), which, as the solu- tion cools, crystallizes out, mixed probably with some of the excess of oxalic acid employed; together with extractive matters and other impurities, which give the crystals a more or less intense brown color. The crystals are to be gently pressed between folds of filtering paper, and then Avashed in a basin with a very small quantity of cold distilled water, which may be poured off, and fresh water added to the crys- tals as long as it continues to become decidedly colored; by Avhich means most of the soluble salts and other foreign matters are removed. 54. The washings are now to be concentrated to a small bulk by evaporation on a water bath, and left to cool, when a fresh crop of crystals will gradually separate. Care must be taken that an excess of oxalic acid is present in the HEALTHY URINE. 43 liquid separated from the crystals, which may be known by its reddening litmus paper ; if this is found on trial not to be the case, a little more of the pounded oxalic acid must be added to the solution, as otherwise, some of the urea, which, when uncombined, is very soluble in water, might escape separation. 55. When the whole of the oxalate of urea has been sepa- rated by successive crystallizations from the liquid, it must be gently pressed between folds of filtering paper, and dissolved in warm water ; after which the solution is to be digested for a feAv hours, at a temperature of about 100° F. with pounded carbonate of lime, stirring the mixture from time to time Avith a glass rod, as long as any efferves- cence is produced. The oxalate is thus decomposed in the following manner : Oxalate of urea. Oxalate of lime. C^iHi02,HO,C&+Ca,0,COi=CalO,Ci03 + C02 + HO Urea. + 6'>2//402. 56. The urea, Avhich being soluble remains in solution, is to be separated by filtration from the insoluble oxalate and carbonate of lime, and carefully evaporated to dryness either on a water bath or in vacuo over sulphuric acid {Prac. Chem. 646). Its weight will then represent the proportion of UREA in 1000 grains of the specimen of urine under examination. 57. The portion of the residue Avhich proved insoluble in the alcohol (52), containing the uric acid, vesical mucus, the extractive matter soluble in water but insoluble in alcohol, the earthy salts, and most of the other saline matter, is now to be well stirred with successive small portions of warm water, Avhich leaves undissolved the uric acid, mucus, and earthy salts. The insoluble matter is to be placed in a platinum or porcelain crucible,1 previously weighed or counterpoised, and then carefully dried on a water bath, or in a hot-water oven, and weighed. The weight having been noted, the dry residue is to be ignited in the crucible, until the incombustible ash becomes white, or very nearly 1 See Introduction to Practical Chemistry, second edition, p. 195. 44 QUANTITATIVE ANALYSIS OF so ; when the crucible with its contents is to be again weighed. The difference between this Aveight, and that of the dry residue previous to ignition, gives the amount of combustible matter, consisting of uric acid and vesical mucus ; while that of the ash represents the earthy phos- phates and silica. 58. The portion of urine A will now have given us the weight of, 1. The water; 2. Urea; 3. Uric acid and Vesi- cal mucus ; and 4. Earthy phosphates and Silica. 59. For the purpose of ascertaining the respective weights of the uric acid and vesical mucus, 2000 grains of the fresh urine may be concentrated by evaporation to about half its bulk, and mixed Avith twenty or thirty drops of hydrochloric acid. In the course of twenty-four hours, the whole of the uric acid will have been set free by the hydrochloric acid, and being insoluble (22), will be deposited in the form of minute crystals on the sides and bottom of the glass. These are to be collected on a weighed filter, and after being washed with a little alcohol, dried in a hot-Avater oven or on a water bath. The weight of this acid, divided by two (since it is derived from 2000 grains of urine), will repre- sent the uric acid contained in 1000 grains of the secre- tion ; and having already determined the quantity of uric acid and vesical mucus together (57), the weight of the latter is known by deducting from the combined weights that of the uric acid. 60. The proportion of uric acid and mucus may also be determined by evaporating to dryness 1000 grains of the urine, previously filtered from the mucus, and washing the residue first Avith dilute hydrochloric acid (containing one part of acid to eight or ten of Avater), and afterwards with a little alcohol. We thus dissolve out everything but the uric acid, which, after being washed with cold water, may be dried and weighed. 61. If it is required to determine the respective propor- tions of earthy phosphates and silica, in the residue of earthy salts (57), which, however, is seldom necessary, since the quantity of silica is always very small, it may be done in the following manner: Moisten the residue with hydro- chloric acid, and evaporate to dryness; then digest it with the aid of a gentle heat in dilute hydrochloric acid, which HEALTHY URINE. 45 will dissolve out the phosphates, leaving the silica per- fectly insoluble {Prac. Chem. 426). The weight of the latter is then ascertained, and deducted from the gross weight of the earthy salts (57), Avhen the difference will represent that of the earthy phosphates ; or the phosphates may be precipitated from the hydrochloric acid solution by supersaturating it with ammonia, filtered, ignited, and weighed. 62. We have now to operate upon the residue left after the evaporation of the second portion of urine marked B (50), for the purpose of determining the weights of—1, the animal extractive and ammoniacal salts ; and 2, the fixed alkaline salts. 63. The dry residue, after being accurately weighed, is to be incinerated in a platinum or porcelain crucible, until the whole of the blackness (carbon) has disappeared, after which the weight of the ash is to be noted. The loss expe- rienced during ignition being due to the combustion of the organic matters and the volatilization of the ammoniacal salts; and as Ave have already ascertained the weight of the urea, uric acid, and vesical mucus, Ave have only to deduct from the whole amount of loss the combined weights ^ of those three substances, in order to determine the quantity of the animal extractive and ammoniacal salts. 64. The ash obtained by ignition contains the whole of the inorganic matter, or, in other words, the fixed alkaline and earthy salts contained in the urine. By deducting from this the Aveight of the earthy salts already determined (57), we obtain the proportion of fixed alkaline salts. 65. We shall thus have determined the proportion of the Water, Urea, Uric acid, Vesical mucus, Animal extractive and ammoniacal salts, Fixed alkaline salts, Earthy phosphates, Silica, which, when added together, ought to make up a fraction less than 1000 grains, some slight loss being unavoidable during the course of the analysis. 46 quantitative determination of Quantitative determination of the Inorganic Salts. 66. When it is required to estimate the proportion of the several inorganic salts, whether earthy or alkaline, which are contained in the urine, the following plan will be found simple and conA'enient; or if the estimation of one or two only of the ingredients is required, some modification of it may be adopted. 67. Weigh out two portions of the inorganic ash (57) in powder, one of 50 grains, and the other 10 grains. The first (50) grains we will call A, and the second (10 grains) B. The portion B will serve for the estimation of the chlorine (69), and the portion A for that of the other saline ingre- dients (68). 68. Digest the portion A in about four ounces of hot water; filter, and Avash the insoluble residue Avith a little more hot water, in order to dissolve out the whole of the soluble matter. We thus divide A into two parts, both of Avhich must be retained for subsequent examination: 1st, the insoluble or earthy salts, Avhich we will call C (70); and 2d, the soluble or fixed alkaline salts, which portion we will call D (75). 69. While the washing and filtering of A is going on, digest the portion B, consisting of ten grains of the ash, in about two ounces of hot Avater, and wash the insoluble resi- due on a filter until the AAThole of the soluble matter is dis- solved out from the residue of earthy salts, which latter may be thrown aAvay. Acidify the aqueous solution thus obtained Avith a little nitric acid, and add a solution of nitrate of silver as long as it causes any precipitate. The chloride of silver (AgCl) thus precipitated, is now, after boiling, filtered, dried, and Aveighed, and the chlorine calculated as follows : Ate. wt. of chloride Ate. wt. of Weight of chloride AVt. of chlorine in of silver. chloriue. obtained. 10 grs. of the ash. 144 : 36 : : ~a~~ : ~~T~ which, when multiplied by five (10x5=50), will represent the quantity of chlorine in fifty grains of the ash. The liquid filtered from the chloride of silver need not be re- tained. 70. The insoluble residue C (68) may now be examined, THE INORGANIC SALTS. 47 for the purpose of estimating the quantity of lime, magnesia, and phosphoric acid, contained in the earthy phosphates. It is to be dissolved in a little dilute nitric or hydrochloric acid, and filtered from any carbonaceous or siliceous matter that may resist the action of the acid. The acid solution of the earthy phosphates is now supersaturated with am- monia, Avhich will throw them doAvn in the form of a white precipitate. This precipitate is to be washed on a filter, dried, and, after gentle ignition in a platinum or porcelain crucible, weighed. This weight will, of course, represent the quantity of earthy phosphates in fifty grains of the ash. 71. The weight of the earthy phosphates having been taken (70), they are to be redissolved in dilute nitric or hydrochloric acid, again thrown down by neutralizing the acid solution with ammonia, and once more dissolved by adding an excess of acetic acid ; the acetic acid being here used as the solvent, because the oxalate of lime, which is about to be precipitated, is insoluble in an excess of acetic acid, but soluble in most of the other acids (169, 170). 72. Oxalate of ammonia is now added as long as it causes a precipitate; and the oxalate of lime (CaO,C203+2Aq) thus thrown doAvn, is filtered, washed, dried, gently ignited, by which it is converted into carbonate (CaO,C02), and weighed (171). The weight of lime contained in the fifty grains of ash may then be calculated as follows : Ate. wt. of car- Ate. wt. AVt. of carbonate Wt. of lime contained bonate of lime. of lime. of lime obtained. in 50 grs. of ash. 50 : 28 :: a : x 73. The solution filtered from the oxalate of lime (72), is now again strongly supersaturated Avith ammonia, which Avill throw doAvn the magnesia in the form of the double phosphate of ammonia and magnesia (2MgO,NH40,POg+ 12Aq). The mixture is well agitated, and allowed to stand some hours, in order to insure the separation of the Avhole of the magnesian salt; after which the precipitate is washed with a little dilute ammonia, in which it is less soluble than in pure Avater, dried, ignited (by which it is converted into phosphate of magnesia (2MgO,P05),) and weighed. From the weight thus obtained, that of the magnesia in fifty orains of the ash may be calculated as follows: 48 QUANTITATIVE DETERMINATION OF Ate. wt. of phosphate of Ale. wt of AVt. of phosphate AVt. of magnesia magnesia (2Mg0,P0). magnesia. obtained. in 50 grs. of ash. 112 : 40* :: a : x 74. The weight of the phosphoric acid contained in the earthy phosphates may iioav be estimated by adding to- gether that of the lime and magnesia and deducting the sum of them from the entire Aveight of the earthy phos- phates, obtained in paragraph 70. 75. The soluble portion of the ash, D, containing the alkaline salts, and Avhich was dissolved out from the earthy salts (68), must noAV be examined. The solution is acidi- fied Avith a little nitric acid, and then treated with a solu- tion of chloride of barium as long as any precipitate is pro- duced. The sulphuric acid of the ash is thus thrown down as sulphate of baryta (BaO,S03), Avhich is to be filtered, washed, dried, ignited, and weighed. From the weight of the sulphate of baryta thus obtained, that of the sulphu- ric acid, in fifty grains of the ash, is calculated as follows : Ate. wt. of sul- Ate. wt. of sul- Wt. of sulphate of Wt. of sulphuric acid phate of baryta. phuric acid. baryta obtained. in 50 grs. of the ash. 117 : 40 :: a : x 76. The acid solution, filtered from the sulphate of ba- ryta (75), must now be concentrated to about half or one- third its bulk, and then neutralized or slightly supersatura- ted with ammonia: a little more of the solution of chloride of barium being added, to insure the precipitation of the Avhole of the phosphoric acid. This Avill throw down the phosphoric acid previously in combination Avith the alkaline bases, in the form of phosphate of baryta (2BaO,HO,P05), Avhich is to be washed with a small quantity of water, dried, ignited, and weighed. From the weight of the phosphate of baryta thus obtained, that of the phosphoric acid in the alkaline portion of the fifty grains of ash, may then be cal- culated as follows : Ate. wt. of Ate. wt. of Wt. of phosphoric acid in phosphate phosphoric Wt. of phosphate of the alkaline salts of 50 of baryta. acid. baryta obtained. grs. of the ash. 226 * 40=20x2 ; because each equivalent of the phosphate (2MgO,P03) contains two equivalents of magnesia. THE INORGANIC SALTS. 49 77. It may be mentioned that the results afforded by this method of estimating the phosphoric acid in the alka- line salts, are not perfectly accurate, the composition of the phosphate of baryta not being always precisely the same, and that salt being also to a slight extent soluble in water, especially when ammoniacal salts are present in the solution. It will, however, be found sufficiently accurate for all practical purposes. 78. The excess of baryta introduced in the chloride of barium (75), is now to be removed from the solution. This is done by boiling the solution with a mixture of caustic ammonia and carbonate of ammonia, as long as any precipi- tate is produced. When it is supposed that the Avhole of the baryta has been precipitated, a drop or two of the clear liquid should be taken, and tested with a solution of sul- phate of soda ; if this causes no precipitate, it may be safely concluded that the whole of the baryta has been precipi- tated as carbonate. The mixture is then filtered from the precipitated carbonate of baryta ; the filtered liquid is eva- porated to dryness, and the residue gently ignited, in order to expel the ammoniacal salts. 79. The residue after ignition, consisting merely of the chlorides of potassium and of sodium, is now to be weighed. It is then dissolved in a small quantity of water mixed with a solution of bichloride of platinum, and the mixture is evaporated to dryness, or nearly so, on a water bath. The residue is treated with successive small portions of alcohol, which will dissolve out the excess of the bichlo- ride of platinum, together Avith the chloride of sodium; leaving undissolved the double chloride of platinum and potassium (KCl,PtCl2). The latter is to be dried in a weighed filter, at a temperature of 212°, and weighed. From the weight of the double chloride thus obtained, we may then calculate that of the potash equivalent to it, as follows : ^ioT^S? Atcwtof Wt. of the double Wg? and potassium. potash. chloride obtained. ^««^_^ 247 : 48 :: a : x 80. From the weight of potash thus obtained, we are enabled to ascertain how much of the mixed chlorides (79) 50 quantitative determination of was chloride of potassium ; and the difference between the latter and the gross weight Avill of course represent the quantity of chloride of sodium. The weight of chloride of potassium equivalent to the potash, is for this purpose calculated as follows : Ate. wt. of chlo- Wt. of pot- Wt. of chloride of potassium con- ride of potassium, ash obtained, tained in the mixed chlorides. : 76 :: a : x 81. The weight of chloride of potassium thus calculated, is then deducted from the Aveight of the mixed chlorides (79), and the difference Avill represent the weight of chloride of sodium ; thus : Weight of mixed chlorides .... Deduct weight of chloride of potassium Weight of chloride of sodium 82. The whole of the soda, however, does not exist in the urine as chloride of sodium, a portion of it being in combi- nation with phosphoric, and perhaps also with some of the other acids present. We have therefore to calculate from the quantity of chlorine obtained in a former experiment (69), hoAV much of the chloride of sodium obtained in para- graph 81, existed as such in the urine. This is done as follows : Ate. wt. of Ate. wt. of chlo- Wt. of chlorine in Wt. of chloride of sodium chlorine. ride of sodium. 50 grs. of ash. in 50 grs. of ash v —' ——v---------' a : x 36 : 60 83.^ The quantity of chloride of sodium thus calcu- lated is deducted from the whole weight of chloride of sodium previously obtained (81), and the difference will represent the amount of chloride of sodium equivalent to the soda which in the urine was combined with phosphoric or other acids ; thus: Ate. wt. of chlo- Atc.wt. Difference between g0da existine as such ride of sodium. of soda. ^™S$£ t'toT^ofZZt ---sr-----' v------v-------' 60 : 32 :: a the inorganic salt 84. All the quantities obtained in the foregoing experi- ments (67 to 83), represent the amounts of the several saline ingredients contained in fifty grains of the ash : as, how- ever, the organic ingredients were estimated as contained in 1000 grains of urine (65), the proportion of the inor- ganic constituents should also be reduced to the same scale. This may be done in the case of each constituent by the folloAving calculation: i Quantity of inor- in 1000 grs. of j urine. Wt. of each consti- tuent obtair i from 50 the ash. AVt. of thatconsti- ' tuent contained I in 1000 grs. of | urine. CHAPTER III. AVERAGE COMPOSITION OF HEALTHY URINE. 85. The following analyses of healthy human urine will serve to give some idea of its average composition. Although the amount of the several constituents will be seen to differ considerably from each other, it will be found that the dif- ferences are not really quite so great as they at first sight appear, being in a great measure owing to variations in the relative proportions of water and solid ingredients (1). Analysis 1. (Berzelius.) Water, . Urea,..... Uric acid, .... Lactic acid, lactate of ammonia matters, . Mucus, . . . • Sulphate of potash, Sulphate of soda, Phosphate of soda, Biphosphate of ammonia, Chloride of sodium, Muriate of ammonia, . Phosphates of lime and magnesia, Silica, ..•••• and extractive 933-00 30-10 1-00 17-14 0-32 3-71 ^ 3-16 2-94 1-63 4-45 1-50 1-00 0-03 1000-00 52 AVERAGE COMPOSITION OF Analysis II. (Simon.') Specific gravity, 1012. Water,........956-000 Urea,........14-578 Uric acid, ........ 0-710 Extractive matters and ammoniacal salts, . . 12-940 Chloride of sodium,......7'280 Sulphate of potash,......3-508 Phosphate of soda, ...... 2-330 Phosphates of lime and magnesia, . . . 0*664 Silica,........a trace 998-000 Analysis III. (Dr. Miller.') Specific gravity, 1020. Water, Urea, Uric acid, . Alcohol extractive, Water extractive, Vesical mucus, . Muriate of ammonia, Chloride of sodium, Phosphoric acid, Sulphuric acid, Lime, Magnesia, . Potash, Soda, 956-8000 14-2300 0-3700 12-5270 1 1-6050 0-1650 0-9154 7-21951 2-1189 1-7020 0-2101 0-1198 1-9260 0-0536 999-9623 29-822 Organic matters. 13-158 Fixed salts. 42-98 Solid matters. Analysis IV. (Marchand.) Water, Urea, Uric acid, Lactic acid, Extractive matters, Mucus, Sulphate of potash, Phosphate of soda, Sulphate of soda, Biphosphate of ammonia, Chloride of sodium, . Muriate of ammonia, Phosphates of lime and magnesia, Lactates, . 933-199 32-675 1-065 1-521 11-151 0-283 3-587 3-056 3-213 1-552 4-218 1-652 1-210 1-618 66-8 Solid matters. 1000-000 HEALTHY URINE. 53 Analysis V. (Lehmann.) Water, ..... Urea, ..... Uric acid, ..... Lactic acid, .... Water and alcohol extractives, Lactates, ..... Chlorides of sodium and ammonium, Alkaline sulphates, Phosphate of soda, Phosphates of lime and magnesia, Mucus,..... 937-682 31-450 ' 1-021 1-496 10-680 1-897 3-646 7-314 3-765 1-132 0-112 1000-195 62-318 Solid matters. Analysis VI. (Becquerel.) Showing the comparative composition of Hale and Female Urine. Specific gravity, . Water, Solid constituents, Urea, Uric acid, Other organic matters Fixed salts, Consisting of— Chlorine, Sulphuric acid, Phosphoric acid, Potash, Soda, lime, and magnesia Mean composition of the urine of four healthy men. 1018-9 968-815 31-185 13-838 0-391 9-261 7-695 Ditto of four healthy women. 1015-12 975-052 24-948 10-366 0-406 8-033 6-143 General mean. 1017-01 971-935 28066 12-102 0-398 8-647 6-919 0-502 0-855 0-317 1-300 3-944 CHAPTER IV. MORBID URINE. 86. The urine passed during a diseased state of the system, is almost invariably more or less altered in its com- position, and frequently presents physical peculiarities, as of color, opacity, &c, which are at once apparent on the most cursory examination. The variations which are found 5* 54 MORBID URINE. to occur in the chemical composition of morbid urine may be divided into two classes, viz., 1st. Those in which no abnormal ingredient is present; but in which one or more of the normal constituents is present either in greater or less proportion than is found in healthy urine, or is altogether absent. 2d. Those in which one or more abnormal ingredients are present, which are not found in the healthy secretion. I. Urine containing no abnormal ingredient, but in which an excess or deficiency of one or more of its normal constituents is present. SECTION I. Urine containing Urea in abnormal quantity. 87. Urine containing an excess of urea, is chiefly cha- racterized by its high specific gravity, in which respect it resembles that secreted by diabetic patients (116). If the urea be present in large excess, it deposits irregular rhom- boidal crystals of the nitrate (C2N2H402,H0,N05), when the urine, either in its natural state, or especially when slightly concentrated, is mixed Avith an equal quantity of nitric acid (181). The proportion of urea present in healthy urine is usually about fourteen or fifteen parts in 1000 (10); while in disease it often amounts to thirty parts, or even more. SECTION II. Urine containing Uric (or Lithic) Acid in abnormal quantity. 88. When urine contains an excess of uric acid, it has usually rather a higher color than the healthy secretion, either deep amber or reddish brown. Its specific gravity is seldom much higher than 1020 or 1025, unless an excess of urea is also present, which is not unfrequently the case. It generally has a slightly acid reaction to test paper ; and if the uric acid is present in any considerable excess, it is partially deposited as the urine cools, in the form of a crys- talline sediment, usually of a more or less decided red color, and frequently mixed with urate of ammonia, mucus MORBID URINE. 55 and other matters. The crystalline forms in which uric acid is found in the urine, are represented in figure 30, paragraph 186. This deposition of uric acid is greatly accelerated by the addition of a few drops of nitric or hydrochloric acid to the urine (20). 89. The urine of infants and young children not unfre- quently deposits lozenge-shaped crystals of nearly pure uric acid, containing only a trace of yellow coloring matter. It rarely hapens that uric acid is deposited in the solid state previous to emission, being held in solution in the warm liquid, and gradually separating in the form of a sediment, as the secretion cools (186). 90. The quantity of uric acid, which, in the healthy secre- tion, is seldom more than from 0*3 to 1-0 in 1000 parts, varies in morbid urine from a scarcely perceptible trace, to upwards of two parts in 1000. SECTION III. Urine containing an excess of Urate (or Lithate) of Ammonia. 91. Urine containing an excess of urate of ammonia varies very much in color and appearance, being sometimes pale and of low specific gravity, but more frequently high- colored, dense, and turbid. It is most commonly slightly acid, but is also met with neutral and even alkaline. The urate of ammonia is gradually deposited as the urine cools, in the form of an amorphous precipitate, which, with a high magnifying power, appears to consist of minute rounded Fig. 11. *■ ■■]$' '"*'■' Urate of Ammonia. Urate of Ammonia. particles, occasionally adhering together, and forming irregular linear masses (Fig. 11); frequently mixed with 56 MORBID URINE. microscopic crystals of uric acid ; and occasionally, when the secretion is neutral or at all alkaline, with the earthy phosphates (106). 92. Urate of ammonia has been met with in a few rare cases, in the form of globular masses of a larger size, and pierced with spicular crystals, probably of superurate of ammonia (Fig. 12). Like the other varieties of urate of ammonia deposit, it is usually found mixed with crystals of uric acid. 93. Urate of ammonia constitutes one of the most com- mon of the urinary deposits. The color of the sediment is found to vary considerably, being met with of all shades, from pale fawn color to reddish purple or pink, the latter colors being due to the admixture of purpurine, which is very frequently found associated with urates (104, 217). Traces of the urates of soda, lime, and magnesia, are not un- frequently found associated with urate of ammonia deposits. 94. A deposit of urate of ammonia readily dissolves when the urine containing it is gently warmed ; and is again pre- cipitated as the liquid cools. If, however, as is often the case, it contains also an admixture of free uric acid or earthy phosphates, the deposit will not wholly dissolve on the application of heat, those substances being nearly as inso- luble in hot as in cold water. The presence of purpurine (104, 217) usually renders the urate less easily insoluble when warmed. 95. When a deposit of urate of ammonia is treated with a little dilute hydrochloric or acetic acid, it is decomposed; and minute crystals of uric acid shortly appear, which may be readily distinguished under the microscope (194). SECTION IV. Urine containing Urate (or Lithate) of Soda (NaO,C10N,H4O6)- 96. Urate of soda is not unfrequently met with in the urine of patients taking medicinally the carbonate or other salts of soda. It may generally be recognized Avithout difficulty under the microscope, usually forming minute globular and sometimes granulated aggregations, with occa- MORBID URINE. 57 sionally irregular and curved protuberances, as shown in figure 13. 97. It resembles the urate of ammonia in being soluble in hot water (22, 192), and Fig-13- also in most of its chemical characters ; giv- 0 ^ X^ ing the same purple-colored residue when ^s^ tested with nitric acid and ammonia (23). 9 W*~ J& ° It also yields crystals of uric acid, when ^ jl * 9 treated Avith dilute hydrochloric acid (194). q w Q When Avarmed with potash, however, it does Urate of Soda not of course give off ammoniacal fumes (377); and by this, and more especially by its behavior before the bloAvpipe (202), and by its microscopic appearance, it may be readily distinguished from the ammoniacal salt. The two salts are frequently found occurring together in the same deposit. SECTION V. Urine containing an excess of Hippuric Acid. 98. There is but little that can be said to be characteristic in the appearance of urine in which an excess of hippuric acid is present. It is most commonly either neutral or slightly acid to test paper, but occasionally alkaline; and is in most cases pale and whey-like, and of low specific gravity. The mode of its detection will be found described in paragraphs 206, &c. SECTION VI. Urine containing an excess of Mucus. 99. Mucous urine is most commonly very similar in color to the healthy secretion. It deposits a viscid, tenacious sediment, usually of a dirty yellowish color, consisting chiefly of mucus mixed with epithelium (328); Avhich, when agitated, does not mix again uniformly Avith the fluid, but coheres together in tenacious, ropy masses, entangling and retaining numerous bubbles of air. 100. Urine containing an excess of mucus is generally neutral or slightly acid Avhen passed, unless it has been retained some time in the bladder, when it is not unfre- quently alkaline ; and when this is not the case, it very 58 MORBID URINE. speedily becomes so, owing to the rapid com^ersion of the urea into carbonate of ammonia under the influence of the mucus (11). This change takes place first in the portion of the fluid which is in contact with the mucous sediment: this may frequently be seen in specimens of slightly acid urine, the upper portions of Avhich redden litmus paper; but if the lower part, more immediately in contact Avith the mucus be tested, it will be found to restore the original blue color. 101. Mucous urine differs from that containing pus, in the ropy and tenacious character of the deposit; and also in not giving any sensible indication of albumen Avhen tested Avith heat and nitric acid (254), unless the albumen be derived from some other independent source, which is sometimes the case (255). Minute traces of albumen, in- deed, are present in the undiluted mucous fluid, but the quantity is so small, that, when mixed with urine, it is in- capable of being detected (663). 102. The mucous deposit is frequently found mixed Avith a considerable quantity of earthy phosphates or urates, in Avhich case it is more liable to be mistaken for pus. The true nature of such a mixed deposit is, however, readily distinguished by microscopic examination, which should always be had recourse to in such cases (156, 211, 328). SECTION VII. Urine containing an excess of Extractive Matters and Ammoniacal Salts. 103. Urine containing extractive matters in excess is usually more highly colored than the natural secretion, a large proportion of what is included under the title of extractive matter, consisting apparently, in most cases, of the peculiar coloring matters of the urine. When boiled, and subsequently mixed with a little hydrochloric acid, such urine becomes of a more or less decided red color (215), and on cooling, usually deposits a quantity of brownish or bluish-black sediment, which is readily soluble in alco- hol. 104. It is not unfrequently the case, that the peculiar red coloring matter called purpurine is present in considerable quantity in certain forms of morbid urine. This, when a MORBID URINE. 59 deposit of urate of ammonia is also present, is precipitated Avith the urate, giving the sediment a pink or red color (217). When no deposit of urate exists, the purpurine remains in solution, giving the urine a more or less bloody appearance, Avhich may sometimes lead to the suspicion that blood is present. For the methods of identifying pur- purine, see paragraphs 216 to 221. SECTION VIII. Urine containing an abnormal proportion of Fixed Alkaline Salts. 105. When these salts are present in excess, they tend to raise the specific gravity of the secretion. The quantity of soluble saline matter may be readily estimated in the mass, by incinerating the dry residue left after evaporating a known weight of the urine, and treating the ash with water, which will dissolve out the alkaline salts, leaving the earthy phosphates and silica undissolved. The aqueous solution is then evaporated to dryness, ignited, and weighed. The individual proportion of the several salts, which is sometimes a point of considerable interest, may be deter- mined in the manner described in paragraphs 66 to 84. SECTION IX. Urine containing the Earthy Phosphates in abnormal quantity. 106. The physical characters of urine containing an ex- cess of earthy phosphates vary considerably. The color is most commonly pale, and the specific gravity rather low, but it is also occasionally dark, and of high specific gravity, especially when urea is present in large quantity (87, 301). It is generally slightly acid Avhen passed, but shortly becomes neutral or alkaline (43), when the phosphates are precipitated, often in large quantity, in the form of a crys- talline sediment, the color of Avhich varies from white and gray to a dirty yellow or reddish brown. When white or gray, the sediment will probably be found to consist chiefly of phosphates mixed Avith mucus; when yellowish or red, it Avill probably be found to contain, in addition, a certain amount of uric acid, or urate of ammonia, most commonly the latter. 60 MORBID URINE. 107. It must be borne in mind that the spontaneous occurrence of a precipitate of earthy phosphates, is not of itself a proof that they are present in excess ; nor, on the other hand, is the non-occurrence of a deposit a proof that a small quantity only is present. When the urine is acid, as in health, they may be retained in solution in conside- rable quantity, without forming any solid sediment; while if the secretion is neutral or alkaline, a comparatively small amount of earthy phosphates may be precipitated in the form of a deposit. 108. When examined with the microscope, deposits of the earthy phosphates will frequently be found to contain both the crystalline triple phosphate (MgO,NH40,HO,P05), and also phosphate of lime, in the form of an amorphous poAvder, or in minute, irregular, rounded particles (43, 44). 109. The quantity of earthy phosphates, which, in healthy urine, is usually about one part in 1000, varies, in disease, from a scarcely perceptible trace to 5-5 in 1000 parts, and is occasionally even higher. When present in excess, they may generally be partially precipitated by warming the urine (49). 110. It sometimes happens, in certain forms of disease, that the earthy phosphates are secreted in much smaller quantity than is found in healthy urine, and in some rare cases they appear to be altogether absent. Whether this is the case in any specimen of the secretion, may be ascer- tained by adding to it a slight excess of ammonia, when, if present only in a very small proportion or not at all, no precipitation will take place : or the ash of the urine may be digested in dilute hydrochloric or nitric acid, and the clear acid solution supersaturated with ammonia, when, if no precipitate is produced, it may be concluded that no perceptible trace of earthy phosphate is present. II. Urine containing one or more abnormal ingredients. 111. The abnormal matters usually found in morbid urine are, 1, sugar; 2, albumen ; 3, blood; 4, biliary matter; 5, pus; 6, fat and chylous matter ; 7, semen ; 8, oxalate of lime ; 9, cystine; 10, iodine, and other foreign matter?. URINE CONTAINING SUGAR. 61 Besides the substances just enumerated, various others may be occasionally detected in urine, such as arsenic, antimony, and many other saline and organic matters, Avhich, having been taken into the system medicinally or othenvise, and being incapable of assimilation, haA-e passed through either unchanged, or more or less modified in composition. SECTION X. Urine containing Sugar (C7,2/714014). 112. The variety of sugar ahvays present in the urine of diabetic patients, and hence called diabetic sugar, has the same chemical composition as that contained in most kinds of fruit, commonly known as grape sugar, or glucose. It appears to contain two eqvivalents of Avater of crystalliza- tion, which may be expelled at a temperature of 212° ; so that its composition may be more correctly expressed by the formula (Cl2H~l2012-\-2Aq). 113. Diabetic sugar may be obtained by concentrating the urine containing it, by evaporation on a water bath, until it begins to deposit a crystalline sediment; the mass is then alloAved to cool, on which the greater part of the sugar crystallizes out. It is then filtered; and Avhen most of the liquid has passed through, the crystals are to be pressed betAveen folds of filtering paper, and Avashed Avith a small quantity of cold strong alcohol, Avhich serves to remove the greater part of the impurities, Avithout dissohr- ing much of the sugar. The crystals are then dissolved in hot Avater, and purified by successive crystallizations, or, if necessary, by boiling with animal charcoal. 114. Diabetic sugar differs from cane sugar (C12HuOn) in being considerably less sweet to the taste, harder, and less soluble in water ; one part requiring about one and a half of cold water to dissolve it. In dilute alcohol, on the other hand, it is somewhat more soluble than the cane variety ; but is insoluble in absolute alcohol and ether. It is usually in the form of granular crystals ; but when crystal- lized out of a considerable mass of syrup, it is often obtained in needle-like tufts. When crystallized from its solution in dilute alcohol, it usually separates in the form of hard transparent cubes, and occasionally in square plates. An 62 M 0 It B I I) U R I X E. insipid modification of diabetic sugar has been met Avith in a feAv rare cases; it appears, in other respects, to possess the same properties as the common diabetic sugar. 115. Strong sulphuric acid dissolves grape sugar, forming a pale yellowish solution; cane sugar, on the contrary, is almost instantly charred and blackened by the strong acid. 116. Urine containing sugar is usually characterized by its high specific gravity, Avhich is frequently from 1030 to 1045, and occasionally as high as 1050 and 1055. If, how- ever, the sugar is present only in small quantity, the specific gravity may not be higher than usual; so that a moderately low specific gravity is of itself no proof of the absence of sugar. 117. Diabetic urine has usually, after standing a short time in a Avarm atmosphere, a white scum, someAvhat re- sembling flour, on the surface, consisting of minute oval- shaped confer void vesicles (132), which is highly character- istic of the presence of sugar, and occasionally leads to its detection before it has been secreted in sufficient abundance to raise the specific gravity of the urine to a suspicious extent. 118. This variety of urine is usually paler than the natural secretion, and frequently possesses a faint greenish tint. It is most commonly slightly turbid. When fresh, it has a faint and rather agreeable odor, somewhat resem- bling that of hay. 119. The proportion of urea in diabetic urine is usually much smaller than that found in the healthy secretion : but whether the absolute amount secreted differs materially from the normal average, or whether the apparent deficiency is merely owing to the large quantity of water passed by diabetic patients, thus largely diluting the urea, has not yet been satisfactorily decided, owing to the difficulty of cor- rectly estimating the quantity of urea when mixed with any considerable amount of sugar (334). 120. The proportion of sugar in diabetic urine varies from a mere trace to from 50 to 80 parts in 1000; and has been known to amount to as much as 134 parts in 1000. 121. Several tests have been proposed for the detection of sugar in urme. Of these, the following only need here be noticed, viz., Trommers test, Maumenes test, Moore's URINE CONTAINING SUGAR. 63 test, the fermentation test, and the test afforded by the growth of a microscopic confervoid vegetation, called the torula. 122. Trommer s test. This excellent test is founded on the circumstance, that when a solution containing diabetic or grape sugar (112) is boiled with a mixture of potash {KO) and sulphate of copper (CuO,S03), the oxide of copper (CuO) contained in the latter becomes reduced to the state of suboxide (Cu20), which is precipitated in the form of a reddish or ochre-colored granular powder. 123. A little of the urine suspected to contain sugar is placed in a tolerably large test tube, and mixed with a drop or tAvo of a solution of sulphate of copper, which should be added only in sufficient quantity to give the mixture a very pale blue tint. This will probably cause a slight precipita- tion of pale blue phosphate of copper, owing to the presence of soluble phosphates in the urine (40); this, however, need not be regarded, as it will not afterAvards interfere Avith the indications of the test. A solution of potash is now added in large excess,1 or in quantity equal to about half the volume of urine employed; this will first throw doAvn a pale blue precipitate of hydrated oxide of copper (CuO,HO), which, if sugar is present, will immediately redissolve, forming a purplish-blue solution, something similar to that caused in a very dilute solution of copper by ammonia (797). 124. The mixture is now to be carefully heated over a lamp, and gently boiled for some minutes; Avhen, if sugar is present, a reddish or yellowish-broAvn precipitate of sub- oxide of copper (Cu20) will be deposited in the liquid. If no sugar is present, a black precipitate of the common oxide of copper (CuO) Avill be thrown doAvn, totally dis- tinct in appearance from the suboxide. It is important, in this experiment, not to add too much of the sulphate of copper, because, in that case, the suboxide might be mixed with some of the black oxide (the sugar being capable of reducing only a certain definite quantity), which would more or less mask the characteristic color and appearance 1 Or the potash may be added, and the solution filtered from any de- posit of earthy phosphates that may be thrown down, before the addition of the sulphate of copper. 64 MORBID URIXE. of the suboxide. This test is extremely delicate, and is capable of detecting very small traces of sugar in the urine. 125. Maumenes test. This test is founded on the cir- cumstance, that Avhen sugar is moderately heated in con- tact with the bichloride of tin (SuCl2), it is decomposed, and a brownish-black compound, somewhat resembling caramel, is formed. The most convenient method of apply- ing this test is to saturate strips of merino, or some other woollen tissue,1 Avith a solution of bichloride of tin (prepared by dissolving the salt in about tAvice its weight of water), after which they may be dried at a gentle heat on a water bath, and kept ready for use. On moistening one of these strips with urine, or any other liquid containing sugar even in a highly diluted state, and holding it near a fire, or over a lamp, so as to heat it to about 270° or 300° Fahr., it im- mediately assumes a broAvnish-black color. The delicacy of this test is stated to be so great, that though ordinary healthy urine causes no change of color, if ten drops of diabetic urine be diffused through half a pint of water, the mixture will immediately give decided indications of sugar. 126. Moore's test. Mix a little of the suspected urine in a test tube, with about half its volume of liquor potassae, and boil the mixture gently for about five minutes. If sugar is present, the liquid will assume a brownish or bistre tint; while little or no heightening of color takes place when the urine is free from saccharine matter. 127. Fermentation test. This is perhaps the most valu- able test for sugar which we possess, since it is not only capable of detecting it when present in very minute quan- tities, but also supplies a method of estimating the propor- tion contained in any specimen of urine. The mode of em- ploying it in the quantitative determination of sugar will be described further on (333). When used merely as a qualitative test, to indicate Avhether sugar is or is not pre- sent, the folloAving is the simplest way of applying it. 128. Fill a test tube with the suspected urine, having 1 It is necessary in this test to avoid the use of cotton or linen, since those substances, being analogous to sugar in composition, undergo also a similar decomposition when warmed with the bichloride of tin • and would consequently become blackened even though no sugar were pre- sent. URINE CONTAINING SUGAR. 65 previously mixed with it a feAv drops of fresh yeast, or still better, a little of the dried German yeast; close the open end with a small saucer or evaporating dish, and while gently pressing the latter upon the tube, invert them, when they will be in the position shown in the fig- ure (Fig. 14). A little more of the urine is then poured into the saucer, in order to pre- f!j\ vent the escape of any of the liquid from the t:|| tube ; and if any bubbles of air have acci- |H dentally been allowed to enter, the exact 111 height of the upper surface of the liquid tf8 in the tube must be marked with ink, or ^^lJi^^ with a strip of gummed paper. The tube, .^f9Bs^-j~2iIs> with its contents, is then set aside in a Fermentation test. Avarm place, having a temperature of about 70° or 80°, for twenty-four hours. As bubbles of gas are sometimes given off by the yeast itself, it is a good precaution to put the same quantity of yeast into a second tube of equal size, and fill it up with pure water. The amount of gas, if any, derived from the yeast, will thus be rendered apparent, and may afterwards be deducted from the volume of gas in the tube containing the urine. 129. If sugar is present it begins almost immediately to undergo the vinous fermentation, by which it becomes converted into alcohol (C.R^O^O) and carbonic acid (C02), each equivalent of sugar giving rise to the formation of two equivalents of alcohol, four of carbonic acid, and two of water, thus: CuIIu01^2(CiHbO,ffO)+4C02+2EO. The carbonic acid thus formed rises in minute bubbles, causing gradual and gentle effervescence, and collects in the upper part of the tube ; at the same time displacing the liquid, Avhich escapes through the open end of the tube into the saucer. 130. That the gas thus formed is really carbonic acid may be proved by decanting a little of it over Avater into a clean tube1 and testing it with lime-water, which will in- stantly become milky, owing to the formation of the insoluble 1 See Introduction to Practical Chemistry, second edition, p. 14. 6* 66 MORBID URINE. carbonate of lime (CaO,C02). When the quantity of sugar present is at all considerable, the urine, after fermentation, will be found to possess a faint vinous smell, due to the alco- hol formed during the process. 131. If, on the contrary, the urine is free from sugar, of course no fermentation will take place, and no gas will be formed in the tube. 132. Test afforded by thegroivth of the torula. During the process of the vinous fermentation of a liquid containing sugar, a delicate white scum gradually collects on the sur- face, which when seen merely with the naked eye, is so highly characteristic an indication of the presence of sugar, as frequently to lead to its detection when present only in very small quantity. If a little of this scum be examined under the microscope, with a magnifying power of four or five hundred diameters, it will be found to consist of minute oval vesicles (Fig. 15), which, in the course of a few hours, rapidly change their form, becoming longer and more tubu- Fig. 15. Fig. 16. Torula Vesicles. Magnified 400 diameters. Torula Stem. lar, and giving rise to new vesicles, which shoot out from the parent body, forming an irregularly jointed confervoid stem (Fig. 16). These again gradually break up into a a great number of oval vesicles, Avhich eventually separate, and fall to the bottom, where they may be detected by mi- croscopic examination. SECTION XI. Urine containing Albumen. 133. This substance, Avhich is contained, as is well known in large quantity, in many of the tissues of the body, and URINE CONTAINING ALBUMEN. 67 especially in the serum of the blood (466), is not unfre- quently present in morbid urine. Albuminous urine varies very considerably in appearance and general characters, being found alkaline, acid, and neutral; high-colored, and pale ; of high specific gravity, and the contrary : so that no general rule can be laid down as to its usual physical peculiarities, likely to lead to its detection ; though, Avhen its presence is once suspected, its detection is easy and simple (139). 134. The quantity of albumen found in urine varies very much, a mere trace only being sometimes present, and at others as much as ten or twelve parts in 1000. 135. The most remarkable property of albumen is, that when a solution containing it is heated to a temperature of about 170°, or higher, it coagulates, and separates com- pletely from the liquid; and when this change has once taken place, it becomes quite insoluble in water. The coagulated albumen is readily soluble in potash and other alkaline solutions ; and when an excess of alkali is present no coagulation takes place on boiling. 136. Albumen is precipitated from its solution by nitric and hydrochloric acids, but not by phosphoric, acetic, or tartaric acids, which, indeed appear to exercise a decided solvent action upon it, and when present, prevent its coagu- lating on the application of heat. 137. It is also readily precipitated, eAren from an acetic acid solution, by ferrocyanide {K2,FeCy3-\-3Aq) and ferrid- cyanide (K3,Fc2Cy6) of potassium ; and the precipitates thus formed, as also the coagulated modification of albumen, are easily soluble in alkaline solutions. 138. Bichloride of mercury {HgCl2\ alum (Al2Ov3S03 JrKO,S03-{-24:Aq), and many other of the metallic salts, also cause precipitates in albuminous solutions, Avhich are probably definite compounds of the acid and base of the salt with albumen. It is precipitated, too, by alcohol, creo- sote, tannin, and many other substances. 139. The detection of albumen in urine containing it is very easy. The suspected urine may be gently boiled in a test tube, when if albumen is present, it will coagulate, and form a more or less copious white precipitate. If the albu- men is present only in minute quantity, it may cause merely (>* MORBID URINi:. a delicate opalescence ; or, Avhen in larger quantity, it may separate in curdy flakes ; and if very abundant, may cause the liquid to gelatinize, and become nearly solid (142). 140. The appearance of a white precipitate on boiling is not, hoAvever, of itself, a sure proof of the presence of albu- men in urine, since a white precipitate is also produced by boiling, Avhen the secretion, free from albumen, contains an excess of earthy phosphates (49 a). It is therefore necessary to add a feAv drops of nitric acid, which, in case the preci- pitate consists of phosphates, immediately redissolves it, but if albuminous, leaves itself still insoluble. 141. To prevent the possibility of error, it is always advisable to test a separate portion of the urine also with nitric acid, by which the albumen, if present, will instantly be thrown doAvn. If the quantity of albumen is very small, it is possible that the milkiness first caused by the acid may disappear, but if a few drops more of the acid be added, the precipitate will again separate, and remain insoluble. If both heat and nitric acid cause a white precipitate, there can be no doubt of the presence of albumen. 142. In testing for albumen, it must be borne in mind, that if the liquid is alkaline to test paper, the albumen, though present, will probably not be coagulated on the ap- plication of heat, since coagulated albumen is readily solu- ble in alkaline solutions (135). On this account the urine should first be examined Avith turmeric or reddened litmus paper (277), and, if found to be alkaline, neutralized with nitric acid before boiling. 143. It should also be remembered, that when the albu- men is present only in small quantity, the addition of a very slight excess of nitric acid may redissolve it, and thus lead to the supposition that the precipitate is phosphatic. A feAv drops more of the acid, however, will instantly cause it to reappear, if albuminous; while, if really phosphatic, no excess of the acid would cause it to do so. Fig 17 144. the peculiar casts of uri- -TBfipsSgBpr^J'______r— "^ tUbeS' f°Und in tne UHne •^WJ^^Jta':^'^ °? Patients suffering from Bright's '^^s^^^^t^M^i£_ disease, consisting of fibrinous or nbrinous Cast. (Dr. q. Johnson.) albuminous matter, and entang- ling blood-corpuscles, epithelium, URINE CONTAINING BILIARY MATTER. 69 and fatty globules, have usually the appearance shoAvn in figure 17. SECTION XII. Urine containing Blood. 145. Urine frequently contains, in addition to albumen, one or more of the other constituents of the blood (450), and is often more or less highly colored red or broAvn, by the presence of the corpuscles and red coloring matter. When the fibrin, in its soluble form, is present, it usually coagulates spontaneously on cooling, and causes the urine to become more or less gelatinous soon after it is passed. This spontaneous coagulation on cooling, may be con- sidered of itself sufficient proof of the presence of the fibrin of the blood. 146. The blood corpuscles may gene- rally be detected both in the coagulum, and also in the superincumbent fluid, when examined under the microscope (451); occasionally, however, they are almost entirely disintegrated, so that little or no trace of their characteristic form remains. They arc sometimes found adhering together, forming little thread-like aggregations; but more „ °V °, , iip i Blood in Lrine. frequently floating detached from each other, looking like little transparent rings (Fig. 18). 147. In urine containing blood, the albumen may in all cases be readily detected by the tests already mentioned (139)—viz., heat and nitric acid; but Avhen any of the coloring matter of the blood is also present, it will coagulate with the albumen, giving the coagulum a more or less decided red or brown color. SECTION XIII. Urine containing Biliary Matter. 148. When biliary matter is present in urine, it generally gives a more or less decided yellowish-brown color, both to the liquid, and also to any sediment that may be deposited 70 MORBID URINE. from it. The taste also of such urine is remarkably bitter ; a peculiarity which furnishes a ready indication of its pre- sence when other tests are not at hand ; though it must not be implicitly relied on, since small traces may exist in the secretion, without communicating to it any very decided taste. 149. Petteiikofer s test. Perhaps the best test for the presence of bile, is that known as Pettenkofer's. If the urine contains albumen, it should first be freed from that substance by coagulation and filtration (135, 151) ; because albumen, Avhen present in considerable quantity, would give, Avith sulphuric acid and sugar, a color resembling that caused by bile. A little of the suspected urine is mixed in a test tube Avith about two-thirds its bulk of strong sulphuric acid, which must be quite free from sulphurous acid {S0.2), since the latter AArould, if present, tend to destroy the color, and thus prevent the proper action of the test. The sul- phuric acid should be added cautiously, drop by drop, in order to preA7ent the evolution of too much heat, since at a temperature of 140°, or a little higher, the characteristic color is destroyed. A grain or tAvo of sugar, or of syrup, are noAV added to the acid liquid ; and the mixture is shaken, and alloAved to stand a few minutes. If bile is present, the liquid Avill gradually assume a more or less intense red color, Avith a tinge of violet. The cause of this change of color is not clearly understood, but it appears to be occa- sioned independently of the biliphaein or coloring matter of the bile, since it is produced equally with decolorized bile. It must be borne in mind, that in liquids containing a con- siderable quantity of soluble chlorides, the color produced by this test is less bright, and more approaching to brown. 150. When the quantity of bile is small, it "is advisable, before applying the test, to concentrate the urine by eva- poration. For this purpose it is first boiled, in order to coagulate any albumen that may be present (151), and afterwards evaporated nearly to dryness on a water bath. The residue is then treated with a small quantity of boiling water or alcohol; and the solution thus formed, containing any biliary matter that may be present, is mixed, when quite cold, Avith about one-third its bulk of strong sulphuric acid, observing the precautions already mentioned (149), URINE CONTAINING PUS. 71 and afterwards Avith sugar ; Avhen the characteristic red color will appear, provided any biliary matter is present. 151. The experiment known as Heller s test is made as folloAvs: Mix with a little of the suspected urine a feAv drops of the serum of blood or Avhite of egg, or of any liquid containing albumen in solution: and having shaken them avcII together, add a slight excess of nitric acid, Avhich Avill cause the precipitation of the albumen (136). If bile is present, the coagulum throAvn down by the acid Avill have a more or less distinct dull green or bluish color, quite dif- ferent from the white or pale faAvn color which it Avould othenvisc be. When only a small quantity of biliary mat- ter is present, the urine may be concentrated, as in Pettcn- kofer's test (150), the serum or white of egg being subse- quently added to the cold concentrated aqueous solution of the evaporated residue. 152. The folloAving test may also be employed in proving the presence of bile in the urine. Pour a few drops of the suspected urine upon a clean Avhite plate or dish, so as to form a thin layer of the liquid, and then carefully add a drop or tAvo of nitric acid. When bile is present in any considerable quantity, the liquid becomes successively pale green, violet, pink, and yellow, the color rapidly changing as the acid mixes with the urine. When the bile is present only in small quantity, these colors are not distinctly visible, but unless the proportion is very minute, a greenish tint is generally perceptible. On concentrating the urine by eAraporation, the appearance may be seen to a greater ad- vantage, when only small traces of bile are present (150). The action of this test appears to depend on the presence of the peculiar brown coloring matter of bile, called bili- phoein. SECTION XIV. Urine containing Pus. 153. Pus is a substance Avhich in many respects closely resembles mucus, both in its behavior with reagents, and still more in its appearance under the microscope ; so that it is not ahvays easy to distinguish betAveen them; and when mixed together in the urine, it is frequently quite im- 72 MORBID URINE. possible to say with certainty whether or not both arc pre- sent. Like mucus, it consists of minute round or oval granular corpuscles (Fig. 19), floating in F'g m^\ tbe flu^' from which they separate on fa® (M \& fS. standing, and gradually sink to the bottom. @) <£*) These form, in urine containing pus, © .t 't£*\ @) a Pa^e greenish-yelloAV or cream-colored *s\ s-y s serve the dumb-bells, they should be put in ^g. \^ balsam, in which they will continue to re- ww <^ tain their peculiar form. There are occa- ^ sionally to be seen also, mixed with the oc- um ofLime.xaae tohedra and dumb-bells, a few minute, flat, disk-shaped particles, having a good deal the appearance of blood corpuscles (451), for which they may readily be mistaken ; they are, however, usually much smaller. 169. Oxalate of lime is readily soluble, without efferves- cence, in dilute nitric and hydrochloric acids, from which it is again thrown down in the form of a white precipitate, vrhen the acid solution is neutralized with ammonia or potash. 170. It is insoluble in both cold and hot water ; also in acetic and oxalic acids ; and in solution of potash. 171. When gently ignited before the blowpipe, it under- goes little or no blackening, and becomes converted into carbonate of lime (CaO,C02), which, when treated with dilute hydrochloric or nitric acid, dissolves with effervescence (399). The solution thus obtained by dissolving the car- bonate in acid, gives, when neutralized, a white precipitate with oxalate of ammonia, but none with ammonia. If the oxalate be kept intensely heated for some little time before the blowpipe, the carbonate itself is decomposed, and caustic lime is formed (402). SECTION XVIII. Urine containing Cystine (C6NH604S2). 172. Cystine has occasionally, though but rarely, been found both as a crystalline deposit in urine, and also in the 1 It appears probable, from the observations of Dr. Golding Bird, that the dumb-bells consist not of oxalate, but of oxalurate of lime (CaO, CGN.,lI307). See his excellent Avork on "Urinary Deposits," fourth edition, p. 219. 78 MORBID URINE. form of small calculi; in one of which latter it Avas first discovered by Dr. Wollaston. A deposit of cystine, when examined under the microscope, usually appears as a mass of minute irregularly formed crystals, having the appear- ance shown in figure 26. To the naked eye, the deposit has a good deal the appearance of pale fawn-colored urate of ammonia (93), from Avhich it may be readily distinguished by being insoluble, or nearly so, in warm water, and conse- quently not disappearing when the urine containing it is gently warmed (94). Fig. 26. Fig. 27. Fig. 28. ® o «g) ®to® g£p&% ^oo° Cystine. Cystine Crystall.zed from Crystals of Chloride of an Ammoniacal Solution. Sodium resembling Cystine. 173. One of the most characteristic properties of cystine is the readiness with which it dissolves in ammonia. If a little of the ammoniacal solution, thus formed, be allowed to evaporate spontaneously on a slip of glass, the cystine is deposited in minute hexagonal crystals, having the form and appearance shoAvn in figure 27. It must be remembered that, occasionally, chloride of sodium crystallizes in octohe- dral masses (Fig. 28), which in some positions may have at first sight very much the appearance of cystine. The ready solubility of the chloride in water, is however,.suffi- cient to prevent such a mistake. The cystals of cystine too, when examined with polarized light, appear beautifully colored, unless very thick, which is not the case with chloride of sodium. The triangular crystals of triple phosphate (44), which in some positions somewhat resemble cystine, may be at once distinguished by their ready solubility in dilute acids (49, 174). 174. Cystine is insoluble in a solution of carbonate of ammonia, but soluble in the fixed alkaline carbonates. It URINE CONTAINING IODINE. 79 is very sparingly soluble in Avater, even when warmed, and insoluble, or nearly so, in alcohol. In acetic acid it is inso- luble, and also in dilute nitric and hydrochloric acids. If, hoAvever, either of the two latter acids be in a concentrated state, a little of the cystine will be found to dissolve. 175. Urine containing cystine has usually a someAvhat paler color than the healthy secretion, with occasionally a greenish tint. Its specific gravity is most commonly rather low. It may generally be distinguished, Avhen fresh, by a peculiar and slightly aromatic smell, a good deal resembling that of sweet briar : this gradually gives place to a foetid, disagreeable odor, owing to the occurrence of putrefactive decomposition. 176. Cystic urine is, in most cases, slightly turbid when passed, and becomes considerably more so as it cools, the cystine being less soluble in the cold liquid. A small quantity of this cystine, however, is still held in solution, and may be precipitated by adding a little acetic acid to the filtered urine. SECTION XIX. Urine containing Iodine and other foreign matters. 177. When the compounds of iodine, as the iodide of potassium, are taken internally, it is generally found that nearly the whole of the iodine is carried off by the kidneys, and may be detected, in some form of combination, in the urine. It may readily be identified by adding to the secre- tion a drop or two of nitric acid or chlorine water, and then testing with a solution of starch ; when, if iodine is present, the liquid will assume a more or less intense purple color, OAving to the formation of iodide of starch (807, 810). ^ 178. Many other substances, taken into the system either as food or medicinally, pass into the urine unchanged, and may frequently be distinguished by their peculiar proper- ties. This is especially the case Avith many of the vegetable coloring matters, as those of indigo, madder, beet root, gamboge, logwood, &c. Some of these may occasionally give rise to the suspicion of the presence of blood, but their real nature may generally be ascertained by examination under the microscope. 80 QUALITATIVE EXAMINATION 179. Besides these coloring matters, various other sub- stances, both organic and inorganic, are occasionally found in urine. Thus, when any metallic preparation has been taken internally, traces of the metal, in some state of com- bination, may usually be found. The inorganic, and some of the organic acids also, are frequently to be detected; though, when neutral salts of the latter have been taken, carbonates of the bases are more usually found. In addi- tion to these, the odorous principles of many vegetables appear to pass off unchanged in the urine, where they may often be recognized by their peculiar smell. CHAPTER V. QUALITATIVE EXAMINATION OF URINE SUSPECTED TO CON- TAIN EITHER AN UNNATURAL PROPORTION OF SOME ONE OR MORE OF THE USUAL INGREDIENTS, OR ELSE SOME ABNORMAL MATTER. 180. It often happens that, owing to some peculiarity of color and appearance, either of the liquid or sedimentary portion of morbid urine, or from some other circumstance, such as its high specific gravity, we are led to form some conjecture as to its real nature. When such is the case, one or two well-selected experiments, such as those about to be described, will generally be found sufficient to decide whether or not the suspected peculiarity really exists. When, however, the observer is unable to form a tolerably strong opinion as to the nature of the urine he is about to examine, he had better proceed to test it according to the directions given in Chapter VI. SECTION I. Examination of Urine suspected to contain Urea in abnormal quantity. ^ 181. When the presence of an excess of urea is suspected, either on account of the high specific gravity of the urine OF MORBID URINE. 81 (301), or from any other cause, a drop or two of the liquid should be placed on a slip of glass, and mixed with about an equal quantity of pure colorless nitric acid. If the urea is present in large excess, there will probably be a deposi- tion of minute rhomboidal crystals of the nitrate in the course of a few minutes (Fig. 29), and if no trace of crystallization is visible to the naked eye, the mix- ture should be examined under the microscope. If no crystals appear in the course of half an hour or an hour, a few drops of the urine may be slightly concentrated by evapo- ration on a slip of glass, at a gentle heat; and when cool, mixed as before, Avith an equal quantity of nitric acid. Crystals of the nitrate Avill noAV separate, if any considera- ble quantity of urea is contained in the urine; and from the rapidity with which the crystals form, to- gether with their abundance, the student will be able, after a little practice, to form a tolerably accurate opi- nion as to the relative amount of urea present in the urine. If a microscope is not at hand, the experiment may be made, though less delicately, Avithout it. It must be re- membered that variations in the atmospheric temperature affect the crystallization of this salt very materially; in cold weather, a specimen of urine will consequently often be found to afford an abundant crop of crystals, which, in warm Aveather, Avould furnish little or none. For this reason it is often advisable to cool the mixture artificially, by im- mersing the glass containing it, either in cold water or a freezing mixture; which latter may be readily made by mixing a little pounded nitrate of ammonia with an equal Aveight of water. 182. A new method of estimating the quantity of urea has recently been contrived by Liebig, which appears likely to prove of considerable practical value. It is founded on the circumstance that urea is capable of combining with nitric acid and peroxide of mercury, to form a nearly in- 82 QUALITATIVE EXAMINATION soluble compound (C2H4N202,N05,4HgO), Avhich is imme- diately precipitated Avhen a solution of urea is mixed Avith a solution of nitrate of mercury containing no free acid. But since this reaction does not take place Avith the bichlo- ride of mercury which is formed, by double decomposition, when the nitrate of mercury is added to urine containing chloride of sodium, it is necessary to remove the chlorine previously to determining the urea; or a larger quantity of the mercury-solution would be employed than was neces- sary to precipitate the urea. The removal of the chlorine is effected by means of nitrate of silver, its quantity having been previously determined by an ingenious application of the principle above stated, that nitrate of mercury will not precipitate urea, in the presence of common salt, until a sufficient quantity of the mercury-salt has been added to convert all the chloride of sodium into nitrate of soda. I will first describe the method of preparing the test so- lutions required, viz.: The solution of nitrate of mercury, No. 1, for determining the chlorine; The solution of nitrate of silver, for removing the chlo- rine ; The solution of nitrate of mercury, No. 2, for determining the urea. Preparation of the Solution of Nitrate of Mercury, No. 1, employed for determining the Chlorine. Pure crystals of protonitrate of mercury are dissolved in moderately strong nitric acid, and the solution heated until a sample is no longer rendered turbid by chloride of so- dium ; the solution is evaporated, on a water bath, to a syrupy consistence, and diluted with about 10 times its bulk of water; it is then set aside for 24 hours, and, if necessary, filtered. In order to graduate the solution, it is requisite to prepare a saturated solution of common salt: pure chloride of sodium (colorless rock-salt) is powdered, and digested with water (at the ordinary temperature) for 24 hours, with occasional shaking; so much salt must be employed that a considerable quantity may remain undis- solved. One hundred and fifty grain-measures of this so- OF MORBID URINE. 83 lution are poured into a small beaker, and mixed with 45 grs. of a solution of urea (containing about 4 per cent. of urea) and with 75 grs. of a cold saturated solution of pure sulphate of soda ; to this mixture the solution of nitrate of mercury is added, from a burette, with constant sjjrring, until a distinct precipitate is permanently formed. The strength of the mercury-solution having been thus ascertained, such a proportion of water must be added to it that 1500 grs. may correspond to 15 grs. of chloride of sodium. Preparation of the Solution of Nitrate of Silver employed for removing the Chlorine. 174-36 grs. of fused nitrate of silver are dissolved in water, and diluted till the solution amounts to 6000 gr. measures; 1500 gr. measures of this solution correspond to 15 grs. of chloride of sodium; 100 gr. measures being equal to one grain of the chloride. Preparation of the Solution of Nitrate of Mercury, No. 2, employed for determining the Urea. A solution of nitrate of mercury is prepared, according to the directions given above, so as to contain about 25 grs. of nitrate of mercury in 180 gr. measures. In order to graduate this solution, 60 grs. of pure urea are dissolved in water, and diluted till the volume of the solu- tion amounts to exactly 3000 grs.; 150 gr. measures of this solution are poured into a beaker, and the mercury- solution is added from a burette till a few drops on a Avatch- glass produce a distinct yellow color with carbonate of soda. This should be the case after the addition of 300 gr. mea- sures of the mercury-solution, but if the latter be prepared of the above strength less than that quantity will be required, and so much Avater must be added to the solution as will bring it to the proper standard; thus, suppose only 296 gr. measures had been used, then to every 296 grains of the solution, 4 grs. of Avater must be added; 100 grs. of this solution correspond to 1 gr. of urea. For the expeditious determination of urea in urine, the 84 QUALITATIVE EXAMINATION analyst should be provided with the following measures, accurately graduated, for the solutions employed :l 1. A pipette with a mark upon the tube indicating the level at which 225 grs. of distilled water would stand. This is employed for measuring the urine after precipita- tion with baryta. 2. A burette, capable of containing 100 grs. of distilled water, for the mercurial solution No. 1. This should be graduated as accurately as possible. 3. A tall narrow glass measure, capable of containing 1000 grs. of distilled water. 4. A. graduated burette, containing 1000 grs., for the mercurial solution No. 2. Having the test solutions ready prepared, it is necessary, before determining the urea in urine, to remove the phos- phoric acid, which is effected by means of a mixture of 2 vols, of cold saturated baryta-water, and 1 vol. of a cold saturated solution of nitrate of baryta. A glass cylinder, of about 1 oz. capacity, is filled to overflowing with urine, the excess being made to flow off by covering the cylinder with a glass plate; two such cylinderfuls are poured into a beaker, and mixed with one cylinderful of the baryta-solu- tion ; the precipitate is filtered off, and the amount of chlo- ride of sodium contained in 225 gr. measures of the filtrate (=150 grs. of urine) is then determined by adding the standard solution of mercury No. 1, till the appearance of a cloudiness ; 450 grs. more of the filtrate are then mea- sured off, and mixed with a quantity of the standard solution of silver equal to twice that of the mercury-solution employed in the preceding experiment; the liquid is then filtered, and half the sum of the mixed liquids is taken for the deter- mination of the urea. This quantity is poured into a beaker, and the graduated mercurial solution No. 2 added from a burette, with frequent stirring, until no further increase of the precipitate is perceptible; to ascertain if sufficient of the mercury-solution has been added, a few drops of the turbid liquid are removed with a pipette into a watch-glass, and a few drops of carbonate of soda carefully added down the edge of the glass; if, after some minutes, the mixture 1 These may be obtained from Negretti & Zambra, 11 Hatton Gar- den. » OF MORBID URINE. 85 retains its Avhite color, a further quantity of the mercury- solution is to be added, until a fresh sample exhibits plainly the yellow color after the addition of carbonate of soda. The number of grains employed is then read off, and the amount of urea calculated, 100 grs. of the solution corresponding to one grain of urea.1 183. The absolute quantity of urea present in urine, may also be ascertained by evaporating 1000 grs. of the urine to dryness on a water bath, in a counterpoised porcelain dish, and treating the residue in the manner described in paragraphs 52 to 56. 184. When it is suspected that the urea is present in smaller quantity than in the healthy secretion, or is even altogether absent, 2000 grs. of the urine are to be eva- porated to dryness on a water bath, and the dry residue well stirred with successive small quantities of alcohol, which will dissolve any traces of urea that may be present. The alcoholic solution is then to be evaporated to dryness on a water bath, and the residue which it leaves is after- wards treated in the manner described in paragraphs 341 and 342, in order to separate the whole of the urea, which may, if necessary, be weighed. SECTION II. Examination of Urine suspected to contain Uric (or Lithic) Acid in abnormal quantity. 185. When urine is suspected to contain an excess of uric acid, it may be examined in the following manner. Pour off the clear liquid from any solid deposit that may have subsided to the bottom, and retain both the solid and liquid portions for examination. 186. A little of the sediment is placed on a slip of glass, and examined under the microscope; when, if uric acid is 1 It has been found that, in analyses of urine, when the amount of urea is increasing, an error is committed, tending to diminish the amount of urea; in order to remove this error, an addition has to be made—for 225 gr. measures of urine, and before the test is applied—of 7-5 o-rs. of water for every 15 grs. of solution of mercury which have been used over and above 450 gr. measures, in the preliminary determination. To obviate an error in the opposite direction, in the more dilute urines, a deduction has to be made of 1*5 gr. measures for every 75 grs. of mer- cury-solution used less than 450 grs. J u 86 QUALITATIVE EXAMINATION Fiir. 30. present in it, either alone, or mixed with the amorphous or rounded particles of urate of ammonia (193), or other matters, it may be distinguished by its peculiar crystalline forms, most of the modifica- tions of which are shown in the annexed figure (Fig. 30.) 187. If the sediment con- sists of uric acid, it will prove insoluble when the liquid is Avarmed. If urate of ammo- nia is also present, however, the latter Avill readily dissolve on the application of heat (192), leaving the crystalline uric acid unaffected. 188. Uric acid sediment is insoluble in dilute hydrochlo- ric and acetic acids, but dis- solves readily in a solution of potash, owing to the forma- tion of the soluble urate of potash (22). 189. When uric acid is moistened with a little tole- rably strong nitric acid, and the residue, after evaporation at a gentle heat, is treated, when cold, with a drop or two of ammonia, or exposed to ammoniacal fumes, a beau- tiful purple color is developed, owing to the formation of murexide (23). 190. The clear urine, sepa- rated from the uric acid sedi- ment (185), being still satu- rated with the acid, the latter may be gradually precipated by adding a few drops of nitric or hydrochloric acid. The uric acid thus precipitated usually has the crystalline forms shoAvn in the upper and middle part of the figure. 191. When a deficiency of uric acid is suspected, the Crystalline forms of Uric Acid. OF MORBID URINE. 87 best way of ascertaining whether or not such is the case is to filter one or two thousand grains of the urine, in order to separate the mucus and any other solid matter which it may contain, and which may be separately examined for uric acid under the microscope (186), or with nitric acid and ammonia (189.) The filtered urine is then evaporated nearly to dryness, on a water bath, and the residue di- gested Avith dilute hydrochloric acid, containing one part of strong acid to eight or ten of water. Any uric acid that may be present will thus be left undissolved, and may be examined under the microscope, or otherwise ; and, if ne- cessary, Aveighed, after being first dried at a temperature of 212° on a water bath. SECTION III. Examination of Urine suspected to contain an excess of Urate (or Lithate) of Ammonia. 192. When a sediment is suspected to consist, either Avholly or partially, of urate of ammonia, a little of the urine containing it is to be warmed over a spirit lamp. If it consists of urate of ammonia unmixed with other matters it Avill readily dissolve as the liquid becomes warm, and, on cooling, will be again precipitated. When purpurine is present (104), the urate will probably not dissolve quite so readily on the application of heat as when it is unmixed Avith coloring matter. 193. Under the microscope, urate of ammonia appears as an amorphous powder, frequently interspersed with minute round particles larger than the rest, some of which are occasionally found adhering closely together. (See Fig. 11, paragraph 91.) More rarely, it is found in the form of large masses, containing spiculse of superurate of ammonia (Fig. 12, paragraph 92.) 194. It must be remembered that phosphate of lime se- diment usually has a very similar appearance _ under the microscope (108), and may consequently be mistaken for urate of ammonia, if the microscopic appearance alone he relied upon. All that is necessary, in order to distinguish between them, is to add a drop of dilute hydrochloric acid to a little of the deposit on a slip of glass. If it consists 88 QUALITATIVE EXAMINATION G> ft Fig. 31. 0f phosphate of lime, it will instantly dissolve on the addition of the acid (49, 322); while, if urate of ammonia, it Avill be acted on much more slowly, and 7 O LI *n a snort time, minute crystals of uric C^/A E*JL £? acid. (FiS' 31). wil1 Sradually appear, If l>^ having been displaced from the urate * C\ f^ by the action of the hydrochloric acid (i96). 0 Uric Acid. NHiO,CwNiHi06+nCl=miiCl + HO\.CwKiH.iOl.. 195. When uric acid coexists in a sediment with urate of ammonia, which is of very common occurrence, it may be distinguished under the microscope, by its crystalline forms (186), totally different from the amorphous or rounded par- ticles of urate of ammonia. The uric acid would also be left undissolved when the liquid is warmed, and may then, if necessary, be separated by filtration, and further exa- mined. 196. Urate of ammonia deposits are not unfrequently found mixed with the earthy phosphates, especially when the urine has at all an alkaline reaction. These will be left undissolved when the liquid is warmed, and may be exa- mined under the microscope, and tested with dilute hydro- chloric acid (317, 322). 197. When albumen is present in urine containing a se- diment Avhich is supposed to consist of urate of ammonia, it may, by coagulating when heated, disguise the solubility of the urate, and thus lead to an erroneous opinion as to the nature of the deposit. If, however, the heat be applied very gradually, the urate of ammonia will be found to dis- solve, some time before any of the albumen coagulates; so that, with care, this source of error may be avoided. Or if the urine has been inadvertently allowed to boil, and a pre- cipitation of albumen has taken place, the liquid may be filtered while hot, and the clear filtered solution will, on cooling again, deposit the urate of ammonia ; which may then, if necessary, be further examined (94, 192). 198. If pus or mucus be contained in the sediment, together with urate of ammonia, the urine will not become OF MORBID URINE. 89 perfectly clear, on the application of heat; nor will those substances dissolve on the addition of dilute hydrochloric acid. They may, however, be distinguished with the aid of the microscope (328, 329). 199. When it is required to estimate the quantity of urate of ammonia in a urinary sediment, a portion of the latter derived from a known quantity of the secretion, is to be boiled with water, and filtered while hot; when the soluble urate will be separated from any uric acid, earthy phosphates, &c, that may be also present with it. The solution is then concentrated by evaporation at a gentle heat, and allowed to cool; Avhen the urate of ammonia will again separate in the solid form, and after drying on a water-bath, may be weighed. SECTION IV. Examination of Urine suspected to contain Urate (or Lithate) of Soda. 200. When gently warmed, the deposit dissolves, similar to urate of ammonia, and reprecipitates on cooling. 201. Under the microscope, it usually appears in the form of small circular, and sometimes semi-crystalline grains, covered occasionally with irregularly formed spiculse, or granular protuberances, as shown in fig. 13, par. 96. 202. When ignited before the blowpipe on platinum foil, it leaves an abundant white fusible residue of carbonate of soda, Avhich is readily soluble in water, forming a solution which is strongly m°-32- alkaline to test paper. ^ O <^ o 203. If the ignited residue be treated, r=| ^7 rg\ on a slip of glass, with a drop of dilute , ° -^ ^ hydrochloric acid, it dissolves with effer- ® ^ O /^ vescence, forming chloride of sodium ; .. <^ [S] ° ^ Avhich, if the liquid be expelled by gen- W ° D <^ tie evaporation, is gradually deposited chloride of sodium. in minute cubical crystals, on the glass, and may be easily recognized with a lens or microscope (Fig. 32). 204. When a little of the deposit, previous to ignition, is placed in a drop of nitric acid on a slip of glass, and 8* 90 QUALITATIVE EXAMINATION the residue, after evaporation, treated with a little ammonia, in the manner described in paragraph 23, a purple color is developed, similar to that caused under the same circum- stances, with uric acid and urate of ammonia. 205. Urate of soda may be distinguished from urate of ammonia, Avhich in chemical properties it much resembles, by its microscopic appearance (91, 96); by not being en- tirely dissipated by ignition (202, 375); by giving no am- moniacal fumes when Avarmed Avith a solution of potash (377); and by the ignited residue yielding, with hydro- chloric acid, cubical crystals of chloride of sodium (203). SECTION V. Examination of Urine suspected to contain an excess of Hippuric Acid. 206. When urine is suspected to contain an excess of hippuric acid, an ounce or so of the liquid is evaporated on a water bath to the consistence of a syrup; which is then mixed with about half its bulk of strong hydrochloric acid. The mixture is set aside, and examined after the lapse of a few hours. If any considerable excess of hippuric acid is present, it will gradually crystallize at the bottom of the dish, in fine tufts of needlelike crystals, often colored pink by the admixture of purpurine, and having the form shown at a, figure 33. Fig. 33. Hippuric Acid. 207. If the acid is present in smaller quantity, there may be merely a few detached microscopic needlelike or branched OF MORBID URINE. 91 crystals, deposited here and there upon the glass, as shown at b in the figure. 208. Hippuric acid is readily soluble in alcohol; the alcoholic solution leaving, after evaporation, a crystalline residue, which has usually the appearance shown at c, figure 33. 209. It is nearly insoluble in cold water, but readily soluble in hot. On cooling, the aqueous solution deposits the acid in Avell-defined prismatic crystals, which are either detached, as in d (Fig. 33), or in tufts, as shown at a. These crystals usually form very beautiful objects under the microscope; and when examined with polarized light, develope colors of great variety and brilliancy. SECTION-VI. Examination of Urine suspected to contain an excess of Mucus. 210. Mucous urine always deposits a viscid, tenacious mass, having an alkaline reaction (100), and consisting chiefly of mucus, often mixed with the earthy phosphates, oxalate of lime, and other matters. If the urine be shaken, the deposit does not again mix uniformly Avith the liquid, but remains cohering in ropy masses, which are very characteristic. 211. When, OAving to the admixture of a large quantity of earthy phosphates, the deposit has no longer the pro- perty of cohering together, the microscope must be resorted to, in order to determine whether or not much mucus is present; the appearance and abundance of the peculiar granular corpuscles (315, 328) furnishing a rough index of the quantity present. . 212. It is possible that pus may also be present, m which case, unless in very small quantity, it may generally be detected in the manner described further on (247-258, 156), where will be found the means of distinguishing between pus and mucus. 213. If it is wished to determine the amount of mucus contained in a deposit, in which it is mixed with earthy phosphates, urates, &c, the sediment must be filtered, and boiled with a little water, in order to dissolve out the urates ; it may then be treated with a little very dilute hydrochloric 92 QUALITATIVE EXAMINATION acid, which will dissolve out the earthy phosphates, when the residue of mucus may, after careful drying on a Avater bath or in a hot-water oven,1 be weighed. SECTION VII. Examination of Urine suspected to contain an abnormal proportion of Extractive Matter. 214. It is often of some importance to be able to identify the presence of an excess of the peculiar yellow coloring matter, of which the bulk of the extractive matter of urine appears to consist; and also that of purpurine, which is probably a morbid modification of the yellow substance. Yellow Coloring Matter. 215. An excess of the yellow coloring matter may be recognized by boiling a little of the suspected urine, and then adding to it a few drops of hydrochloric acid. A more or less intense red color is in this way produced; the intensity of the color indicating the comparative amount of the yellow coloring matter present. In healthy urine, a faint lilac or pinkish tint only is caused by the hydrochlo- ric acid; while if the coloring matter is in large excess, an exceedingly intense crimson is produced. Purpurine. 216. The presence of purpurine, or the red coloring matter so often met with in cases even of very slight derangement of the system, is easily ascertained. Owing to its solubility in water or urine, it is never met with as a depositor se. 217. Purpurine, however, has a remarkable tendency to unite with urate of ammonia (104), and whenever a deposit of that substance is formed in urine containing purpurine, the latter is invariably precipitated with it, giving the sedi- ment, which would otherwise be colorless, or nearly so, a more or less decided pink or red color. When purpurine is present in a deposit of urate of ammonia, the latter is 1 See Introduction to Practical Chemistry, second edition, p. 184. OF MORBID URINE. 93 not so easily soluble in hot water, so that the red deposit does not disappear" so readily on the application of heat, as when no purpurine is present (94). 218. If a deposit of urates, colored with purpurine, be digested in warm dilute alcohol, the purpurine will dissolve, leaving the deposit nearly colorless, and forming a solution of a yellowish-pink color. 219. Urine containing purpurine, when no excess of urates is present, has a more or less decided pink or red color, which may appear at first sight very similar to blood. 220. Purpurine may be distinguished from blood, when present in a sediment, by microscopic examination, when the true nature of the uric deposit will be at once apparent (318, 323), together with the absence of blood disks (330). When treated with warm alcohol also, the coloring matter will be dissolved out (218). 221. Purpurine, when contained in solution in urine, may be precipitated by adding a little Avarm aqueous solu- tion of urate of ammonia, which will, on cooling, separate from the liquid, carrying with it nearly the whole of the coloring matter, forming a pink deposit, and leaving the urine nearly colorless (217). SECTION VIII. Examination of Urine suspected to contain an abnormal proportion of Fixed Alkaline Salts. 222. When an excess or deficiency of any of the fixed alkaline salts is suspected to be present, a knoAvn weight of the urine may be taken, from AAdiich the proportion of the substance in question is estimated in the manner described in Chapter II, paragraphs 66 to 84. SECTION IX. Examination of Urine suspected to contain an abnormal proportion of Earthy Phosphates. 223. If the suspected urine is neutral or alkaline to test paper, a sediment of earthy phosphates may be precipi- tated even in cases where they do not exist in larger pro- 94 QUALITATIVE EXAMINATION portion than in the healthy secretion; so that the mere occurrence of a small phosphatic deposit is not necessarily a proof of their excess (107). 224. On warming the urine, the sediment, if phosphatic, remains undissolved (94, 229). 225. The earthy phosphates are readily soluble in most of the dilute acids, especially hydrochloric, nitric, and acetic. 226. If the acid solution thus formed, be neutralized or supersaturated with ammonia, the earthy phosphates are immediately reprecipitated (49 b). 227. They are quite insoluble in potash, ammonia, and the alkaline carbonates (49 c). 228. A deposit of earthy phosphates may generally be immediately recognized under the microscope. The crystalline forms of the triple magnesian phosphate have been already noticed (44), and these are often mixed with the amorphous phosphate of lime (fig. 34). If a drop of dilute hydrochloric or acetic acid be added, while the sediment is in the field of the microscope, the crystals Mixed Phosphates. will be seen rapidly to dissolve, leaving the liquid clear, unless uric acid, or some other matter insoluble in the acid, be also p resent in the deposit. 229. When urine, containing in solution an excess of earthy phosphates, is boiled, a portion of them is usually precipitated, giving the liquid a turbid appearance, re- sembling the coagulation of a small trace of albumen under similar circumstances (49, 139). It may readily be distin- guished from albumen, by adding a drop or two of dilute nitric or hydrochloric acid, Avhich will immediately redis- solve the precipitate if it consists of phosphates; but if albuminous, will not affect it. When the precipitate is found to dissolve on the addition of the first drops of acid, it is advisable, before concluding that albumen is not pre- sent, to acidify the mixture more strongly ; since the coagu- lum of albumen, when very small in quantity, occasionally OF MORBID URINE. 95 dissolves on the first application of acid, but is wholly re- precipitated on the addition of a feAv drops more of the acid (140-143). 230. If the absence or a deficiency of the earthy phos- phates is suspected, the urine may be treated with a slight excess of ammonia: Avhen, if no precipitate occurs, it may be inferred that they are either altogether absent, or else present in very small quantity. 231. In order to ascertain, in such a case, whether or not any traces of them are present, a pint or two of the urine may be evaporated to dryness, and the residue, after inci- neration, digested with dilute hydrochloric acid, which will dissolve out the earthy salts if any are present. The acid solution thus obtained is then filtered, and supersaturated with ammonia, when if any earthy phosphates are present, they will be throAvn down in the form of a white precipi- tate (49 b). Quantitative determination of the Earthy Phosphates. 232. When it is required to estimate the proportion of earthy phosphates in a deposit containing uric acid and other matters, a portion of the sediment, derived from a known quantity of urine, is first Avashed Avith a dilute solu- tion of ammonia, and then digested with dilute hydro- chloric acid, until the latter ceases to dissolve anything further. The acid solution of the earthy salts, thus ob- tained, is separated from the" insoluble matter by filtration, and then supersaturated with ammonia, which will throw down the Avhole of the earthy phosphates (70). The mix- ture, after standing a short time, to allow the magnesian phosphate (73) wholly to separate, is to be filtered; and the precipitate, after drying at a gentle heat, is to be weighed, when its Aveight will represent the amount of earthy phos- phates in the quantity of urine from which it was derived, SECTION X. Examination of Urine suspected to contain Sugar. 233. When urine is suspected to contain sugar, it may be examined by means of Trommer's test (122), Maumene's 96 QUALITATIVE EXAMINATION test (125), and the fermentation test (127).1 If any white scum or sediment is present, it should also be examined for the torula vesicles, under the microscope (132). 234. The method of estimating the quantity of sugar contained in diabetic urine will be fully described in Chap- ter VII. SECTION XI. Examination of Urine suspected to contain Albumen. 235. A little of the suspected urine is to be gently boiled in a test tube. If any albumen is present, it Avill be coagu- lated, forming a more or less copious white deposit in the liquid. The precautions necessary for the success of this experiment have been already noticed in paragraphs 139 to 143. 236. To another portion of the urine add a few drops of nitric acid, observing the precautions mentioned in para- graph 143. If a precipitate or milkiness be produced by the acid, and also by boiling (235), the presence of albumen in the urine may be considered certain (141). 237. The proportion of albumen in urine may be esti- mated with tolerable accuracy, by boiling a known quantity of the secretion, and separating the coagulum by filtration ; the insoluble matter is then Avashed with a little dilute nitric or hydrochloric acid, in order to dissolve out any earthy phosphates that may have been precipitated (140), dried on a chloride of calcium bath at a temperature of about 240° or 250°, and Aveighed. 238. If the quantity of albumen is so small as not to form a tolerably decided coagulum when boiled, but only to render the liquid opalescent, it will be hardly necessary to proceed with the quantitative determination; and it may be set down as a mere trace. 239.^ The method of making a complete quantitative analysis of albuminous urine will be fully described in Chapter VIII. 1 Even when Trommer's test affords tolerably decided indications of sugar, it is always more satisfactory, when practicable, to confirm the re- sult by the fermentation test; since certain other organic matters be- sides sugar might, if present, cause the formation of the suboxide of copper. OF MORBID URINE. 97 SECTION XII. Examination of Urine suspected to contain Blood. 240. When, from its peculiar red or brown color, or from other circumstances, the presence of blood is suspected in urine, it may first be examined under the microscope, for any blood-corpuscles that may be contained in it (146). If no coagula have separated (145), the liquid should be allowed to repose for a short time, in order to let the corpuscles subside to the bottom; and a drop then taken from the bottom of the vessel will generally be found to contain an abundance of the corpuscles, more or less modified in form and appearance (456). 241. When so much blood is present as to give the urine a decidedly red color, it will probably be unnecessary to wait for the subsidence of the corpuscles; and a drop of the liquid taken indiscriminately will usually be found to con- tain sufficient for microscopic examination. 242. If the blood has coagulated, either in the bladder, or subsequent to emission, it is most probable that the greater portion of the blood-corpuscles will have been en- tangled in the coagula, and may be forced out by gentle pressure under a strip of thin glass, so as to be made visible with the help of the microscope. 243. The urine should also be tested for albumen by heat and nitric acid, in the manner already described (139-143). The coagulated albumen will probably, in this case, be more or less highly colored, OAving to the presence of the color- ing matter of the blood (147, 455). If the urine already contains coagula, or other solid matter, it should be sepa- rated from them by filtration, before being tested for albu- men ; as their presence would tend to mask the appearance of coagulation. 244. If the urine contains much blood, it may probably become" spontaneously gelatinous, owing to the coagulation of the dissolved fibrin (145, 448). This coagulum should be examined under the microscope, since a somewhat similar gelatinous character might be occasioned by the presence of a considerable quantity of mucus (101); or, if the urme be alkaline, of pus (251, 680). The coagulum of fibrin, 98 QUALITATIVE EXAMINATION when pressed betAATeen glasses, is usually found to be com- posed of minute amorphous particles, with a feAv red blood- corpuscles ; quite different in character from the granular mucus-corpuscles (146, 328). 245. Urine containing bile or purpurine (104, 148,), has sometimes nearly the same color and appearance as when blood is present, and may, without care, be inadvertently mistaken for it. If no trace of blood-corpuscles can be detected under the microscope, we should, before deciding that blood is present, prove that the color of the secretion is not due to purpurine or biliary matter, by applying the tests described for the detection of those substances, in paragraphs 219-221, 246, &c. SECTION XIII. Examination of Urine suspected to contain Biliary Matter. 246. When urine is suspected to contain biliary matter, it may be examined by Pettenkofer's and Heller's tests, de- scribed in paragraphs 149 and 151. If these fail to afford indications of it in the urine, the latter should be concen- trated by evaporation on a Avater bath, and the strong aque- ous or alcoholic solution of the evaporated residue again tested (150). SECTION XIV. Examination of Urine suspected to contain Pus. 247. When pus is contained in urine, unmixed with any considerable quantity of mucus, it may readily be distin- guished under the microscope by its containing the peculiar nucleated pus-granules (153, 678). These particles, when the urine is allowed to stand a short time, gradually subside to the bottom of the liquid; and when shaken, again mix readily with the urine, in which respect a deposit of pus differs essentially from one of mucus; the latter forming, on agitation, tenacious ropy masses, which do not again mix uniformly with the liquid (99). 248. As purulent deposits frequently appear to the naked eye very similar to those of the earthy phosphates (106), and as it is often difficult to distinguish between pus OF MORBID URINE. 99 and mucus when they coexist in a specimen of urine, I will mention the more characteristic tests by which purulent deposits may be most readily identified. 249. It must be remembered that the form and gene- ral appearance of the pus and mucus corpuscles vary con- siderably under different pathological conditions of the pa- tient ; so "that it is not unfrequently impossible to distin- guish between them. The granules of pus appear indeed to be identical with those of mucus ; the difference between the two substances being in the composition of the fluid in which the particles float (661, 676). 250. Under the microscope, with a power of about 400 diameters, the pus-granules have the appearance represented at a, figure 35; and on the addi- tion of a little dilute acetic acid, Fig-35, they become much more transpa- rent, and in each corpuscle, one or more internal nuclei are ren- dered visible, having the appear- ance shoAvn at b in the figure. The granules of pus will be found rus-Qranuies. to float about freely in the liquid (156, 678). 251. When the urine is alkaline, the character of the pus contained in it is different; being then thick and gelatinous, closely resembling mucus (680). 252. The granules of mucus present almost precisely the same appearance under the microscope as those of pus, but are usually, perhaps, rather smaller, and less distinctly granular on the surface. The addition of dilute acetic acid renders visible the interior nuclei, as in the case of pus (250). The acid, hoA\Tever, coagulates the fluid portion of the mucus, OAving, probably, to the precipitation of the mucin, before held in solution by a small quantity of alkali (663). In the case of urine containing only a small quantity of mucus, it is uncertain whether this phenomenon of coagulation will be seen, on account of the dilution of the mucous fluid, and also because the coagulation may have been already occasioned by the presence of the large quantity of water (663). When, however, the quantity of mucus is tolerably abundant, the coagulation by acetic acid furnishes a very characteristic reaction. 100 QUALITATIVE EXAMINATION 253. The earthy phosphates, which to the naked eye sometimes closely resemble pus, may be at once distin- guished under the microscope by their crystalline form (43), and also by being readily soluble on the addition of dilute acetic acid (228). 254. The liquor puris, in Avhich the pus granules float, always contains albumen in solution (676). This may be readily detected by the tests of heat and nitric acid, already described (139); unless, indeed, the quantity of urine is so large, compared with that of the pus contained in it, as to have rendered it too dilute. 255. The fluid portion of mucus, on the contrary, con- tains no albumen, or merely a minute trace (663), and con- sequently undergoes no coagulation Avhen heated, or tested with nitric acid. It is, hoAvever, very possible that urine containing an excess of mucus, and no pus, may also contain albumen ; so that the mere presence of albumen in the secretion is not necessarily a proof of the presence of pus (101). 256. A certain quantity of fatty matter, readily soluble in ether, is ahvays present in pus (676, 678), but seldom, and in much smaller proportion, in mucus (663). If, there- fore, the deposit, or the residue after evaporation, be boiled with a little ether, and the ethereal solution thus obtained is found to yield, on evaporation, small globules of yellow- ish fat, it is probable that pus is present. 257. A deposit of pus, when treated with a solution of ammonia or potash becomes converted into a thick gelati- nous mass, often sufficiently tenacious to allow of the tube containing it to be inverted without any of the mixture flowing out. This reaction is very characteristic. 258. Urine containing pus is most commonly either neutral or slightly acid, and becomes alkaline very sloAvly. Mucous urine, on the contrary, even if acid Avhen it is passed, quickly becomes ammoniacal, and alkaline to test paper (100). SECTION XV. Examination of Urine suspected to contain Fat or Chylous Matter. 259. Urine suspected to contain fat, may be examined with a tolerably high power under the microscope, when it OF MORBID URINE. 101 is occasionally found to contain minute oil globules (158, 325). This, however, is not always the case; so that the best way of proving the presence of fatty matter, is to agi- tate a little of the suspected urine with about half its bulk of ether; Avhich will separate the fat from the watery fluid, forming, usually, a yellowish solution, which gradually rises to the surface. The ethereal solution thus obtained may then be _ cautiously evaporated on a water bath, when the fat or oily matter will, if present, be left behind; and may, if necessary, be tested as to its oily nature, by shaking up Avith hot water ; when, if oil or fat, it will break up into minute globules, immiscible with the water (158). 260. Chylous urine is usually so peculiar in appearance, that it can hardly be mistaken for any other morbid condi- tion of the secretion. Under the microscope, it appears to be chiefly composed of amorphous albuminous matter in a minute state of division, mixed occasionally with globules resembling those found in the lymph and chyle. On agita- tion with ether, it will yield abundant traces of fatty matter, and distinct oily globules may occasionally be distinguished. 261. This form of urine always contains albumen in solu- tion. A portion of this, or more probably a little soluble fibrin (145), not unfrequcntly coagulates spontaneously after emission, giving the urine a gelatinous or semi-solid con- sistence. The presence of albumen may be shown by ap- plying to the urine, rendered clear by filtration, the tests of heat and nitric acid (235). 262. If it is required to ascertain the quantity of fatty matter in any specimen of urine, a knoivn Aveight of the secretion may be agitated with successive small quantities of ether ; and the ethereal solution thus obtained will leave, after evaporation, the fatty matter which it had dissolved. This is to be dried on a Avater bath until it ceases to lose any further weight. SECTION XVI. Examination of Urine suspected to contain Semen. 263. Microscopic examination is the only trustworthy means of determining whether or not any traces of semen are contained in urine. The urine should be well shaken, 9* 102 QUALITATIVE EXAMINATION and then left to stand a short time, in order to alloAV the flocculi of mucus and spermatozoa to subside. The greater part of the fluid is then poured off, and a drop containing the sediment, taken from the bottom, and examined under the microscope, with a magnifying power of at least four or five hundred diameters. If semen is present, the sperma- tozoa always contained in that secretion will then be visible (160), together, probably, with the peculiar seminal granules also found in the spermatic fluid (161). 264. Traces of albumen, also, may generally be detected in seminal urine, by the application of heat and nitric acid (235). SECTION XVII. Examination of Urine suspected to contain Oxalate of Lime. 265. When the presence of oxalate of lime is suspected, the urine should be allowed to stand some little time, in order that the sediment may partially subside. A little of the liquid taken from the bottom of the vessel is then treated in the manner described in paragraph 164, and examined under the microscope ; when, if present, the oxalate will be seen either in the form of octohedral crystals (166), or of one or more of the modifications of the dumb- bell (168). ^ 266. Oxalate of lime dissolves without effervescence in dilute hydrochloric acid, and is again precipitated un- changed, when the acid solution is neutralized or supersa- turated with ammonia or potash. 267. If the oxalate-of-lime deposit be gently ignited, and the residue after ignition treated with dilute hydrochloric acid, it will be found to dissolve with effervescence, having been converted, during ignition, into the carbonate of lime (399). 268. When it is required to estimate the amount of oxalate-of-lime sediment, it may, if unmixed with other deposits, be separated by filtration from a known quantity of urine, and weighed. When mixed with earthy phos- phates or urates, the deposit, after filtration, may be washed with a little dilute acetic acid to dissolve out the phosphates (49 b); the mixture is then filtered, and the insoluble por- OF MORBID URINE. 103 tion digested in dilute hydrochloric acid, which will dissolve the oxalate of lime, leaving undissolved any uric acid that may be present. The acid solution is then filtered, if neces- sary, and supersaturated with ammonia; by which the oxalate Avill be again precipitated. It may then be dried on a water-bath, and weighed. SECTION XVIII. Examination of Urine suspected to contain Cystine. 269. The presence of cystine may generally be identified by means of the microscope (172), especially after the de- posit has been dissolved in ammonia, and allowed to crys- tallize, either spontaneously or with the aid of a very gentle heat, from the ammoniacal solution (270). 270. Treat a portion of the suspected deposit with a little solution of ammonia; if it is cystine, it will be found readily to dissolve. Place a drop of the ammoniacal liquid on a strip of glass, and allow it to evaporate spontaneously. The peculiar hexagonal tubular crystals of cystine thus ob- tained, are very characteristic (173). 271. Neutralize the rest of the ammoniacal solution formed in 270, Avith acetic acid ; the cystine, if present, will be precipitated (174). 272. Cystine may be distinguished from urate of ammonia, Avhich it often closely resembles in external appearance, by being insoluble, or nearly so, when the urine containing it is warmed; while urate of ammonia readily dissolves (94, 172). 273. It may be distinguished from the earthy phosphates by its insolubility in acetic acid (174) ; by its appearance under the microscope (317, 320); and also by its ready solubility in ammonia (173). From chloride of sodium cystine may be distinguished by its sparing solubility in Avater (173). 274. If cystine be boiled with a little caustic potash, and the solution tested with acetate of lead, a black precipitate of sulphide of lead will be produced ; in consequence of the large amount of sulphur contained in the cystine (C6NH6 04S2). 104 EXAMINATION OF MORBID URINE. SECTION XIX. Examination of Urine suspected to contain Iodine, or other Foreign Matters not included in the foregoing sections. 275. When the presence of any other kind of foreign matter is suspected in the urine (180), such as metallic salts, iodine, inorganic or organic acids, &c, a few tests, such as hydrosulphuric acid, hydrosulphate of ammonia, &c, will generally lead to their detection without much difficulty. (See Parts IV and V ; also my Introduction to Practical Chemistry, Parts II and III.) If the suspected substance is organic, either the urine itself or the evapo- rated residue may be tested; but Avhen an inorganic sub- stance is to be looked for, it is generally advisable to incinerate the evaporated residue, and test the ash for the substance in question. CHAPTER VI. EXAMINATION OF MORBID URINE, THE NATURE OF WHICH IS ALTOGETHER UNKNOAVN. 276. When a specimen of urine is suspected to differ in some respect from the healthy secretion, it will generally be found easy, by means of a very feAv simple experiments, such as those which I am about to describe, not only to ascertain whether or not such is the case, but also to dis- cover the nature of the particular morbid condition in question ; whether it be that one or more of the normal constituents of healthy urine is present in an abnormal proportion, or Avhether it be due to the presence of some substance which is never found in the healthy secretion. In such an examination, the microscope will be found to afford most valuable and ready assistance, the simple micro- scopic inspection of a deposit often rendering its true nature at once apparent. Whenever, therefore, the student has access to one, he will do well to avail himself of it as much EXAMINATION OF MORBID URINE. 105 as possible ; and he will soon find that, with a little experi- ence, he will be able readily to discriminate between the more common forms of urinary deposits. For the method of distinguishing the several forms of deposit under the microscope, see paragraphs 315 to 332. Fig. 36. SECTION I. Examination of Urine containing some Solid Deposit. 277. The urine may be first tested with blue litmus paper ; if acid, the color will change to red, or reddish pur- ple. Should the blue color remain unchanged, test it with yellow turmeric or reddened litmus paper; if the urine is alkaline—OAving, probably, to the conversion of urea into carbonate of ammonia (11)—the turmeric will become brown and the reddened litmus blue; while if the color in both cases remain unaltered, the urine may be considered neu- tral. 278. The specific gravity of the urine may then be taken. This is most readily done by means of the urinomcter, Avhich is a little in- strument constructed on the principle of the hydrometer, the usual form of which is shown in the annexed figure. The tube, when used, is simply immersed in the urine; and when it has come to rest, the number on the gradu- ated scale, Avhich stands at the level of the liquid, when added to 1000, will represent the specific gravity of the fluid. For exam- ple, if the level of the liquid stands at 5 on the scale, the specific gravity of the urine will be 1005; if at 30, it will be 1030, and so on (301). If a urinometer is not at hand the specific gravity of the urine may be taken by means of a bottle, or even with a small lump of glass.1 279. It is often a matter of some importance to the phy- sician, to be able to determine the amount of solid matter which' is excreted daily from the body, through the kidneys. 1 See Introduction to Practical Chemistry, second edition, p. 54. 106 EXAMINATION OF MORBID URINE. If the weight of the whole quantity of urine passed during the twenty-four hours is ascertained, and also the specific gravity of the whole of it Avhen mixed together, we can, by reference to the following table, learn, with a sufficient de- gree of accuracy for most purposes, the weight of solid matter contained in it. Table, Showing the Amount of Solid Matters and of Water, in Urine of different Specific Gravities. (Dr. G. Bird.) Specific gravity. Grains of solid matter in 1000 grs. of urine. Grains of water in 1000 grs. of urine. Specific gravity. Grains of solid matter in 1000 grs. of urine. Grains of water in 1000 grs. of urine. 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015, 1016 1017 1018 1019 1020 2-33 4-66 6-99 9-32 11-65 13-98 16-31 18-64 20-97 23-30 25-63 27-96 30-29 32-62 34-95 37-28 39-61 41-94 44-27 46-60 997-67 995-34 993-01 990-68 988-35 986-02 983-69 981-36 979-03 976-70 974-:;7 972-04 969-71 967-38 965-05 962-72 960-39 958-06 955-73 953-40 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 48-93 51-26 53-59 55-92 58-25 60-58 62-91 65-24 67-57 69-90 72-23 74-56 76-89 79-22 81-55 83-88 86-21 88-54 90-87 93-20 951-07 948-74 946-41 944-18 941-75 939-42 937-09 934-76 932-43 930-10 927-77 925-44 923-11 920-78 918-45 916-12 913-79 911-46 909-13 906-80 280. The following table, showing the weight of a pint, and of a fluid ounce, of urine, of the different specific gra- vities most commonly met with, will probably also be found useful; since it is generally easier to measure the quantity of urine passed during the day, than to weigh it. It will be seen that a curious coincidence exists between the weight of solid matter contained in a fluid ounce of urine, and the EXAMINATION OF MORBID URINE. 107 last two of the four figures which represent the specific gravity, both numbers being in most cases nearly identical. This affords a ready and tolerably accurate means of reckon- ing the quantity of solids contained in the day's urine, which may be knoAvn by multiplying the last two figures of the specific gravity by the number of fluid ounces of urine passed during the tAventy-four hours. Thus, if the specific gravity is found to be 1025, and the quantity passed 46 ounces, the amount of solid matter contained in it will be very nearly 25x46, or 1150 grains. Table, Showing the Weight of a Pint, and of a Fluid Ounce, of Urine of different specific gravities; and also the Weight of Solid Matter in each Fluid Ounce. (Dr. G. Bird.) Specific gravity of urine. Weight of one pint. Weight of one fluid ounce. Weight of solid matter in one fluid ounce. Grains. 10-28 11-33 12-37 13-42 14-47 15-52 16-57 17-62 18-67 19-73 20-79 21-85 22-91 Specific gravity cf urine. Weight of one pint. Weight of one fluid ounce. Weight of solid matter in one fluid ounce. 1-010 1-011 1-012 1-013 1-014 1-015 1-016 1-017 1-018 1019 1-020 1-021 1-022 Grains. 8837 8846 8855 8863 8872 8881 8890 8898 8907 8916 8925 8933 8942 Grains. 441-8 442-3 442-7 443-1 443-6 441-0 444-5 444-9 445-3 445-8 446-2 446-6 447-1 1-023 1-024 1-025 1-026 1-027 1-028 1-029 1-030 1-031 1-032 1-033 1-034 1-035 Grains. 8951 8960 8968 8977 8986 8995 9003 9012 9021 9030 9038 9047 9056 Grains. 447-5 448-0 448-4 448-8 449-3 449-7 450-1 450-6 451-0 451-5 451-9 452-3 452-8 Grains. 23-98 25-05 26-12 27-18 28-26 29-33 30-41 31-41) 32-57 33-66 35-75 35-83 36-92 281. The deposit may now be for the most part sepa- rated from the urine, by allowing it to subside for a short time, and then pouring off the clear liquid. The portion of urine containing the sediment in suspension may be first examined. For the mode of examining the clear liquid separated from it, see paragraphs 300 to 314. 108 EXAMINATION OF MORBID URINE. Examination of the Solid Deposit. 282. If, owing to some characteristic peculiarity in the appearance of the deposit, or of the urine containing it, or from other circumstances, the observer has reason to sus- pect the nature of the sediment, he may at once proceed to apply the tests for the suspected substance, according to the directions given in Chapter V, page 56. At first, hoAV- ever, and until he has had some little experience on the subject, he will do well to adopt some such method of ex- amination as the folloAving. 283. In the great majority of cases, the deposits con- tained in urine will be found to consist of one or other of the following substances—viz., earthy phosphates, uric acid, urate of ammonia, or oxalate of lime; sometimes alone, sometimes tAvo or more mixed with each other, or with mucus or other matters. The first experiments, there- fore, should be directed to the detection of these four sub- stances. 284. Put a little of the urine containing the deposit, in a test tube, and warm it gently over a lamp. If it rea- dily dissolves it is probably urate of ammonia (192); in which case one or two of the more characteristic tests for that substance may be applied, and the deposit may be examined under the microscope, in order to confirm or correct the first result (91, 194, 197). If purpurine is present Avith the urate, which may be known by its pink or reddish color, the deposit will probably not dissolve so im- mediately on warming as when the coloring matter is absent (192). If the deposit does not dissolve when gently Avarined, nor yet when heated nearly to boiling, it must be further tested as follows (285). 285. If the deposit does not dissolve avhen warmed, add to a few drops of the sedimentary urine in a test tube, a little acetic acid. 286. If the deposit dissolves in acetic acid, it pro- bably consists of earthy phosphates ; the nature of which, Avhether consisting of phosphate of lime, or triple phos- phate, or a mixture of both, may be distinguished by sub- mitting a little of the deposit to microscopic examination (228, 317, 322). (Confirm 47, 225-227.) examination of morbid urine. 109 287. If the deposit proves insoluble in acetic acid, test another portion with a little dilute hydrochloric acid. If it dissolves in the acid, and the acid solution thus obtained gives, when neutralized with ammonia, a Avhite precipitate, it is probably oxalate of lime (266). (Con- firm 319, 266, 267.) 288. If the hydrochloric acid fails to dissolve the deposit, it may be tested for uric acid by means of nitric acid and ammonia, in the manner described in para- graph 23. Uric acid may also be readily distinguished under the microscope (318). (Confirm 187, 188.) 289. If the deposit proves to consist neither of earthy phosphates, uric acid, urate of ammonia, nor oxalate of lime, it must be examined for the other matters which are occasionally, though less frequently, met with in morbid urine, and which have been already noticed in Chapters IV and V. It must be remembered, that in perhaps the majority of cases, urinary deposits do not consist exclusively of any one substance, but contain two or more mixed together; as when the earthy phosphates occur associated with an excess of mucus. The action of the several tests may frequently in this way be more or less masked, and when taken alone, may lead to erroneous conclusions. In such cases, the microscope will be found of infinite value, and should always, when available, be employed (315). 290. If the deposit sinks readily to the bottom of the vessel, forming a pale greenish-yellow sediment, which, on agitation, is again diffused readily and uniformly in the liquid, it probably consists of pus (247). (Confirm 250, 254, 256, 257, 156.) 291. If, on the other hand, the deposit is tenacious and ropy not'mixing uniformly with the liquid when shaken, it probably contains an excess of MUCUS (210). (Confirm 211,100,156.) 292. If the deposit is dark-colored, brown or red, and has been found not to consist of urate of ammonia colored with purpurine (284), it probably contains blood ; in which case the clear portion of the urine (218) will give indica- tions of albumen when heated, or when tested with nitric acid (243). (Confirm 240, 242, 245.) . 9P3 When the deposit is avhite or nearly so, having 10 110 EXAMINATION OF .MORBID URINE. proved insoluble Avhen warmed (284), and also Avhen treated with dilute hydrochloric and acetic acids (285, 286); and is found to be readily soluble in a solution of ammonia, the ammoniacal solution yielding on evaporation hexago- nal crystalline plates, it is probably cystine (272, 270, 273). 294. If the deposit is pale yelloav, tolerably soluble when warmed (200), but does not appear to consist of urate of ammonia, owing to its yielding no traces of ammonia when Avarmed with a solution of potash (205), and appearing under the microscope, not as an amorphous sediment, but in small irregularly shaped roundish or oval particles, with or without projecting protuberances (324), it is probably urate of soda. (Confirm 202, 203, 204.) 295. If, when a little of the urine is agitated with a few drops of ether in a test tube, and the ethereal solution, after separating from the watery portion on which it floats, is found to leave, after evaporation at a gentle heat, a re- sidue of fat or oily matter, the presence of fat may be inferred (259). (Confirm 325.) 296. If the urine is opaque and almost milky in appearance, yielding traces of fat when treated with ether; and is found, when examined under the microscope, to contain an abundant white amorphous or granular deposit of albumen, together probably with small round colorless corpuscles, it probably contains chylous matter (260). (Confirm 261, 326.) 297. If, on examination under a microscope of high mag- nifying power, minute animalcules are visible, having the appearance shown in figure 49, page 95, it is probable that semen is present (160). (Confirm 161, 264.) 298. The following table may serve to facilitate the exa- mination of deposits with reagents. It must, however, be borne in mind, that until the observer has had some little experience in the action of the several tests, he must not depend too much on the result of any one experiment; but must in all cases confirm his suspicions by one or more corroborative tests. examination of morbid urine. Ill Table For facilitating the Examination of Urinary Deposits, by means of Chemical Tests. 299. Test first for the earthy phosphates, uric acid, urate of ammonia, and oxalate of lime (283). 1. The sediment dissolves avhen warmed ; Urate of ammonia (284). Not soluble when warmed ; See 2. 2. Soluble in acetic acid ; Earthy phosphates (286). Insoluble in acetic acid : See 3. 3. Soluble in dilute hydrochloric acid ; Oxalate of lime (287). Insoluble in dilute hydrochloric acid : See 4. 4. Purple with nitric acid and ammonia ; Uric acid (288). If the deposit proves to be neither of the above, it must be one of the following: 5. Greenish-yellow deposit, easily diffused on agi- tation; Pus? (290). 6. Ropy and tenacious ; Mucus f (291). 7. Red or broavn ; not soluble when avarmed ; the fluid portion coagulable by heat and nitric acid; Blood; (292). 8. Soluble in ammonia ; the solution leaving, on evaporation, hexagonal crystals ; Cystine f (293). 9. Yellowish sediment, soluble avhen avarmed; Urate of soda ? (294). 10. Ether yields, after agitation, an oily or fatty residue ; Fatty matter (295). 11. Milky appearance ; Chylous matter (296). 112 EXAMINATION OF MORBID URINE. SECTION II. Examination of Urine containing no Solid Deposit; or from which a Dej)osit has been separated (281). 300. Test the urine with litmus and turmeric paper (277).1 If alkaline, it must be tested for albumen with nitric acid (305, 306). 301. Take the specific gravity (278).1 If the specific gravity is higher THAN 1025, the urine may perhaps be found to contain either sugar or an excess of urea (302, 304). If the specific gravity is not higher than 1025, pass on to 305. See also 304. 302. Whether urea be present in excess, may be ascer- tained by mixing a little of the urine in a watch-glass or test-tube, Avith an equal bulk of pure nitric acid, keeping the glass cool by allowing it to float in cold water. If any excess of urea is present, a more or less abundant crop of crystals of nitrate of urea will, in a short time, appear in the mixture (181). (Confirm 183.) 303. When a microscope is at hand, we can in this manner detect even a very slight excess of urea. A drop of the suspected urine is placed on a slip of glass, and mixed with a drop of pure nitric acid. If even a small excess of urea is present, minute crystals of the nitrate may generally be seen, after a short time, with a very moderate magnifying poAver. 304. To proA^e the presence of SUGAR, a little of the urine may be examined by means of Trommer's test (122), Maumene's test (125), and the fermentation test (127). (Confirm 132.) It must here be borne in mind, that very decided traces of sugar may exist in urine Avithout raising the density to a suspicious extent—so that the mere cir- cumstance of the specific gravity of the urine being below 1025, is no proof whatever of the absence of sugar ; and in any doubtful case it should be carefully looked for by means of the tests above referred to. 305. Boil a little of the urine in a test tube. If the liquid 1 If these experiments had been already made before the separation of the sedimentary and non-sedimentary portions of the urine (281), they need not be repeated. EXAMINATION OF MORBID URINE. 113 remains clear, pass on to 307 ; but if a precipitate is pro- duced, it may be owing to the presence either of albumen (235), or of an excess of earthy phosphates (109). To dis- tinguish betiveen them, add to the boiled portion a few drops of nitric acid. If the precipitate dissolves, and is not reprecipitated by the addition of a few more drops of the acid, it probably consists of earthy phosphates (229), (Confirm 228, 226); while, if it either does not dissolve, or after being dissolved by the first drop or two of the acid, again precipitates Avhen the liquid is more strongly acidified, albumen is indicated (143). (Confirm 137, 138.) 306. It must be remembered that when the urine is alkaline, albumen may be present in it Avithout being coa- gulated by boiling (142). Such urine should therefore be tested for albumen, by means of nitric acid (141). 307. Add to a little of the suspected urine a few drops of nitric acid. If a precipitate is produced, either im- mediately or after a short time, none having been occasioned by boiling (305), an excess of uric acid is probably present (190). (Confirm 23, 288.) If the urine is alkaline, the precipitate thus occasioned may consist of albumen, since that substance would not then be precipitated by boiling (306). 308. Evaporate a little of the urine on a water-bath, to the consistence of a syrup, and add about half its bulk of strong hydrochloric acid. If, after the lapse of a few hours, tufts or branches of needle-shaped crystals are visible, either to the naked eye, or when examined under the mi- croscope, an excess of hippuric acid is probably present (206). (Confirm 208, 209). 309. If the urine is highly colored, it is probable, either that it contains an excess of yellow coloring matter, or that blood, biliary matter, or purpurine, is present. To determine which of these it is,— 310. Boil a little of the urine ; if it contains BLOOD, the albumen will coagulate, mixed with some of the coloring matter (243). (Confirm 240, 245.) 311. If an excess of yellow coloring matter is pre- sent, the boiled urine, when mixed Avith a little hydrochloric acid, Avill assume a more or less decided red color (215). 10* 114 examination of morbid urine. 312. The presence of biliary matter may be proved by Pettenkofer's and Heller's tests (149, 151). (Confirm 152.) 313. If purpurine is present in solution, the urine usually has a more or less decided pink color ; and when a little warm aqueous solution of urate of ammonia is mixed with it, that salt precipitates as the liquid cools, and car- ries with it nearly the Avhole of the purpurine, which gives the precipitate a pink color (221). (Confirm 218, 220.) 314. The folloAving table may be found useful for re- ference (298). Table For facilitating the Examination of the clear liquid portion of Urine by means of Tests. 1. Specific gravity higher than 1025; See 2 and 3. 2. Crystals avith nitric acid ; Excess of urea (302). 3. Fermentation or Trommer's Test, Sugar (304). 4. If neutral or feebly acid to test paper, see 5, &c. If Alkaline, see 7. 5. Precipitate formed on boiling ; soluble in nitric acid ; Excess of earthy phosphates (305). 6. Precipitate formed on boiling ; insoluble in nitric acid ; Albumen (305). 7. Precipitate formed by nitric acid ; Excess of uric acid, or albumen (307). 8. Concentrated urine yields needle-shaped crys- tals avith hydrochloric acid: Hippuric acid (308). 9. If the urine is highly colored, see 10,11,12, and 10. Dark coagulum formed on boiling; Blood? (310). 11. Red color with hydrochloric acid; Excess of coloring matter (311). examination of morbid urine. 115 12. Pink precipitate with warm solution of urate of ammonia ; Purpurine (313). 13. Change of color avith nitric acid, &c. ; Biliary matter (152, 312). section hi. Microscopic Examination of Urinary Deposits (276, 289). 315. Place a drop of the urine containing the deposit (after being allowed to stand a short time, that the sedi- ment may subside) on a strip of glass; cover it with a small square of thin glass, and examine it with a magnifying power of about two hundred diameters. Observe whether the particles are crystalline, amorphous, or organized. If crystalline, refer to paragraph 316; if amorphous, to paragraph 321 ; and if organized, pass on to paragraph 327. When, as is frequently the case, the deposit appears to consist of a mixture of two or more different forms of matter, each of these should in succession be examined, until the nature of the whole of the deposit is clearly understood. 316. If the deposit is crystalline, it is probably either uric acid, triple phosphate, or oxalate of lime; or possibly cystine. 317. If the crystals are stellate (Fig. 37), or trian- gular prisms (Fig. 38), instantly disappearing on the addi- tion of acetic acid, they consist of the triple phosphate. (Confirm 286.) 318. If the crystals are lozenge-shaped, or possess any of the forms shown in figure 39 ; being insoluble in dilute acids, but tolerably soluble in a solution of potash, they are probably uric acid. (Confirm 288.) 319. If the crystals are octohedra (Fig. 40), or some modification of the dumb-bell form (Fig. 41); insoluble m acetic acid, but readily soluble in dilute hydrochloric acid, they are probably oxalate of lime. (Confirm 287.) 320. If the crystals are multangular plates, having the rosette-like form shown in figure 42; insoluble, or nearly so, in water and dilute acids, but readily soluble in ammonia, the ammoniacal solution leaving, on evaporation, MICROSCOPIC EXAMINATION Fig. 37. Fig. 40. Fig. 39. Fig. 41. ^> OF MORBID URINE. 117 Fig- 42. Fig. 43. ® o o hexagonal crystalline plates (Fig. 43), they are pro- bably cystine (293). 321. If the deposit is amorphous, or in minute rounded particles, it probably consists of phosphate of LIME, OR URATE OF AMMONIA ; Or possibly URATE OF SODA, fat, or chylous matter. See also 327, &c. 322. If it is INSOLUBLE AVHEN WARMED, but DISSOLVES immediately on the addition of acetic or dilute hydro- chloric acid, it is probably phosphate of lime (228). (Confirm 47, 225-227.) 323. If it dissolves readily when the urine containing it is warmed, and is again deposited on cooling, it is pro- bably urate of ammonia. (Confirm 284.) 324. If the deposit is in the form of pale yellowish grains, with or Avithout small irregular protuberances (Fig. 44), dissolving more or less readily avhen warmed, but not consisting of urate of ammonia, it is probably urate of soda. (Confirm 294.) 325. If the substance is in the form of minute round GLOBULES, AVITH DARK AND WELL-DEFINED OUTLINES (Fig. 45), and dissolves avhen agitated with ether, it probably consists of fatty matter. (Confirm 295.) 326. If the urine is opaque and milky in appearance, yielding fatty matter when agitated with ether, and contain- ing minute amorphous albuminous particles, and perhaps also colorless globules, it probably contains CHYLOUS MATTER. (Confirm 296.) 327. If the deposit consists of organized particles, it probably consists either of mucus (which is usually mixed Avith more or less epithelium), pus, blood, or semen. See also paragraph 132. 118 MICROSCOPIC EXAMINATION 328. If the PARTICLES ARE ROUND, OR NEARLY SO, AND granulated on the surface, entangled in tenacious stringy masses, which do not break up and mix uniformly with the liquid on agitation, it is probably MUCUS (Fig. 46, a). (Confirm 291.) Epithelial debris may be recognized by the peculiar forms of its particles (Fig. 46, b). (156.) Mu- cous urine very generally contains also a considerable amount of earthy phosphates and other matters (211). 329. If the particles are round and granular (Fig. 47), not being held together by any tenacious matter, but float- ing freely in the liquid, the deposit probably consists of PUS. (Confirm 290, 156.) 330. If the particles appear as circular and slightly concave disks, the outlines being occasionally irregular (Fig. 48), and of a more or less decided yellowish color, it is probable that blood is present. (Confirm 290.) 331. If the particles, or any among them, have the form of seminal animalcules, or spermatozoa, shown in Fig. 49, semen is probably present. (Confirm 297.) Fig. 44. Fig. 45. OF MORBID URINE. 119 Fig. 48. Fig. 49. 332. The following table may be useful to the student for reference, in the microscopical examination of urinary deposits. Table For facilitating the Microscopical Examination of Urinary Deposits. 1. If the deposit is crystalline, see 4 to 7. 2. If amorphous, or rounded particles, see 8 to 12. 3. If organized particles, see 13 to 17. Crystalline. 4. Lozenge-shaped crystals, and other forms shown in figure 39 ; Uric acid (318). 5. Stella, or three-sided prisms (Figs. 37 and 38); Triple phosphate (317). 6. Octohedra, or dumb-bells (Figs. 40 and 41); Oxa- late of lime (319). 7. Rosette-like tables (Fig. 42); Cystine (320). Amorphous or Rounded Particles. 8. Soluble when avarmed ; Urate of ammonia (323). 9. Soluble in acetic acid ; Phosphate of lime (322). 10. Yelloavish grains (Fig. 44); Urate of soda ? (324). 11. Round globules with dark edges (Fig. 45); Fatty matter (325). 12. White and milky ; Chylous matter ? (326). 120 quantitative analysis Organized Parlides. 13. Granulated corpuscles, in stringy aggregations (Fig. 46); Mucus (328). 14. Irregularly-shaped scales (Fig. 46, b); Epithe- lium (328). 15. Detached granulated corpuscles (Fig. 47); Pus (329). 16. Blood-corpuscles (Fig. 48); Blood (330). 17. Spermatozoa (Fig. 49); Semen (331). CHAPTER VII. QUANTITATIVE ANALYSIS OF DIABETIC URINE. 333. In the quantitative examination of diabetic urine, it is generally sufficient to estimate merely the quantity of sugar, since the determination of the other constituents is of comparatively small practical importance in diagnosis. When this is the case, all that is necessary is, to ferment 250 grains of the urine in the manner described below (336); and from the amount of carbonic acid evolved, to estimate the quantity of sugar which yielded it. 334. It is, hoivever, frequently of importance to be able to determine the proportion of some of the other matters coexisting in the urine, especially the urea (119), which has been supposed by some to diminish, and by others to increase materially in quantity, simultaneously with the appearance of sugar. The exact estimation of small quan- tities of urea, when mixed, as in diabetic urine, with a large amount of sugar, is attended with considerable practical difficulty; and, indeed, the results hitherto obtained must be regarded merely as approximations to the truth. By the method of analysis which I am about to describe, the proportions of the following substances may, without much difficulty, be determined; or the inquiry may be limited to the estimation of the sugar and the urea (335, 341):— 1, water; 2, sugar; 3, urea; 4, uric acid and vesical mucus ; OF DIABETIC URINE. 121 5, animal extractive and ammoniacal salts; 6, fixed alkaline salts ; and 7, earthy salts. 335. Two portions of the urine, A Aveighing 1000 grains, and B weighing 500 grains, are to be evaporated to dry- ness (50), in weighed or counterpoised dishes, on a water or chloride-of-calcium bath; or, still better, in vacuo, over sulphuric acid.1 While the evaporation of A and B is going on, a third portion, C, consisting of 250 grains of the urine, may be weighed out, for the purpose of esti- mating the sugar, which is done in the folloAving manner (336). 336. Treatment of the portion C.—Put 250 grains of the urine into a small wide-mouthed bottle, capable of holding an ounce and a half, or two ounces of water; to the mouth of which is adapted a cork, fitted Avith tubes of the form shown in the figure (Fig. 50). The bottle should be gra- duated in cubic inches and tenths, in order to enable the experimenter to estimate the amount of carbonic acid which is retained in solution by the liquid, at the close of the operation (338). The tube a is nearly filled with small fragments of dry chloride of cal- cium, which are prevented from falling out by a loose plug of cotton avooI placed at each end. The tube b, which reaches nearly to the bottom, is made open at both ends; the top, however, being accurately closed by means of a small bit of cork or wax, e, during the process of fermentation. 337. Mix a feAv drops of fresh yeast, or, still better, about fifty grains of dry German yeast (128), Avith the urine in the bottle; and having placed the cork, with its tubes, firmly in the neck, Aveigh the Avhole apparatus, Avith its con- tents, as accurately as possible. Allow the apparatus to stand a day or tAvo in a Avarm place, having a temperature of about 70° or 80° ; and when the fermentation appears to have entirely ceased, remove the small plug of cork or Avax from the tube b, and bloAV air gently doAvn it, for the pur- pose of expelling the carbonic acid contained in the bottle, 1 Sec Introduction to Practical Chemistry, second edition, p. 194. 11 122 QUANTITATIVE ANALYSIS and replacing it with common air. The small plug is then attached to the tube b, as before, and the Avhole apparatus is again weighed. 338. The amount of loss "will indicate the quantity of carbonic acid Avhich has escaped through the tube a ; but as carbonic acid is soluble, at ordinary temperatures, in about its OAvn bulk of AArater, the portion of acid held in solution by the liquid must be added to that Avhich has escaped. This amount is readily knoAvn, since each cubic inch of liquid, Avhich may be supposed to be saturated with the acid, must contain about a cubic inch of the gas, Aveigh- ing rather less than half a grain.1 339. The whole amount of carbonic acid formed during fermentation, therefore, is determined by adding to the loss of weight half a grain for every cubic inch of liquid contained in the bottle, the quantity of Avhich is known by the graduations on the surface (336). Thus, supposing the loss of weight during fermentation to have been 4*1 grains, and the volume of liquid in the bottle 1*2 cubic inch, the weight of the carbonic acid formed must be 4*l+ll2, or 4-7 grains. 340. Now, since every equivalent of diabetic sugar (C12HuOu) is converted, during fermentation, into two equivalents of alcohol (CJIhO,HO), four equivalents of car- bonic acid (C02), and tAvo equivalents of water (HO); C1,Hu0li=2(C47/5,0, TIO) + 4CO,+2HO ; it follows that every 198 parts by weight of sugar (one equivalent) give rise to the formation of 88 parts of carbonic acid (four equivalents); so that every 88 grains of carbonic acid would indicate 198 grains of sugar ; or, in other words, one grain of carbonic acid will represent 2-25 grains of sugar. Therefore, by multiplying the weight of carbonic acid by 2-25, we obtain the weight of sugar present in the quantity of urine operated on. Thus, in the above ex- ample, 4-7 grains multiplied by 2-25 (=10-57), gives the weight of sugar in 250 grains of urine ; which Avhen multi- plied by four (250x4=1000), represents the proportion in 1000 grains of the secretion. 1 One hundred cubic inches of carbonic acid weigh 17-26 trains • ono cubic inch, consequently, weighs 0-47 of a grain. OF DIABETIC URINE. 123 341. Treatment of the portion A.—The dry residue left after the evaporation of the 1000 grains marked A (335), is to be used for estimating the urea, which is usually present only in minute proportion in diabetic urine. For this purpose, the residue is treated with successive small quanti- ties of alcohol, stirring the mixture with a glass rod, until it ceases to dissolve anything more. The alcoholic solution is now to be evaporated to dryness on a water-bath, and the residue treated with strong alcohol (absolute alcohol, if pos- sible, 114), which Avill dissolve out the urea, leaving undis- solved most of the sugar and other matters. The alcoholic solution thus obtained is to be again evaporated to dryness on a water-bath, and the residue treated, as long as any- thing dissolves, with warm distilled water, Avhich Avill sepa- rate the urea from most of the other matters which are less soluble in Avater. 342. The impure aqueous solution of urea thus obtained is evaporated to a small bulk, and while at a temperature of about 190° or 200°, mixed with as much pounded oxalic acid (HO,C203+3Aq) as will dissolve in the liquid (14). The mixture, after cooling, is immersed in a freezing mix- ture ;* AYhen the whole of the oxalate of urea, together with the excess of oxalic acid, will crystallize out. The liquid is now to be poured off, and the crystals gently pressed be- tween folds of filtering paper, in order to remove as much as possible of the soluble impurities contained in the water. The crystals are to be redissolved in warm water, and the solution thus obtained, mixed and well stirred Avith finely pounded carbonate of lime (CaO,C02) as long as any effer- vescence occurs ; by which means the oxalic acid is sepa- rated from the urea, Avhich remains uncombined in the so- lution (8). After filtering, the aqueous solution, containing the urea, is placed in a small Aveighed or counterpoised dish, evaporated to dryness on a water-bath, or in vacuo over sulphuric acid, and accurately weighed; when its weight Avill represent the proportion of urea in 1000 grains of the urine. 1 A little pounded ice or snow, mixed with about half its weight of common salt; or in the absence of ice, a mixture of equal weights of nitrate of ammonia aud water, will be found the most convenient freezing mixture. 124 QUANTITATIVE ANALYSIS 343. Treatment of the portion B.—The residue left after the evaporation of the 500 grains of urine marked I>, may be examined, for the purpose of estimating, 1, the Avater; 2, uric acid and vesical mucus; 3, animal extractive and ammoniacal salts; 4, fixed alkaline salts ; and 5, earthy salts. For this purpose it is to be carefully evaporated until it ceases to lose Aveight, either on a water or chloride- of-calcium bath, or still better, in vacuo over sulphuric acid, since by long exposure to a high temperature, a portion of the sugar loses five equivalents of water, and becomes con- verted into a kind of uncrystallizable caramel, thus causing the residue to Aveigh less than it ought to do. It is gene- rally a matter of considerable difficulty to expel the last traces of Avater from the residue of diabetic urine ; for ordi- nary purposes, hoAvever, this is not of much importance, since the small error which it here occasions affects only the proportion of the Avater and animal extractive, and not that of the tAvo substances of most importance—viz., the sugar and the urea. 344. The dry residue B is to be Aveighed; and by de- ducting its Aveight from that of the urine before evapora- tion (500 grains), the proportion of water is determined ; which when multiplied by tAvo (500x2=1000), gives the proportion of avater in 1000 grains of the secretion. 345. The weight of the dry residue having been carefully noted, it is to be treated with boiling water as long as any- thing appears to dissolve. In this Avay, the sugar, urea, animal extractive, and alkaline salts are dissolved out, leaving a small insoluble residue, consisting of vesical mucus, uric acid, earthy phosphates, and traces of silica. 346. The aqueous solution thus formed is to be evapo- rated to dryness on a water-bath, and retained for subse- quent experiments (349). 347. The weight of the matter insoluble in water (345), having been noted after careful drying, it is to be incine- rated until the residue becomes white or pale gray. The ash thus obtained is to be Aveighed; and its weight, multi- plied by two, furnishes the proportion of earthy salts in 1000 grains of the urine. 348. The difference between the weight of the ash and that of the dry insoluble residue previous to ignition (347), OF DIABETIC URINE. 125 represents the quantity of insoluble organic matter, con- sisting of uric acid and mucus, in 500 grains of the urine, which must be multiplied by two, as in the former cases; in order to give the proportion in 1000 grains of the secre- tion. 349. The dry residue obtained by evaporating the aqueous solution (346), consisting of the soluble matters of the urine, is now to be Aveighed. It consists of tAvo portions, the organic or combustible, and the inorganic or incombustible. The relative amounts of these tAvo portions are determined by incineration ; the weight of the ash representing the fixed alkaline salts in 500 grains; which, as before, is to be multiplied by two. 350. The loss of weight experienced during incineration (349), Avhich is that of the soluble combustible matters— viz., sugar, urea, animal extractive, and ammoniacal salts, is also to be multiplied by two. Now, since we know from our experiments with the other portions of urine A and C, the weight of the sugar and urea (340, 342), we can, by deducting their combined weights from the amount of loss during ignition, obtain the proportion of animal extrac- tive and ammoniacal salts, contained in 1000 grains of the urine. 351. Thus Ave shall have determined the proportions of the several ingredients of the urine, Avhich together should amount to a fraction less than 1000—viz., Water, ......... Sugar,......... Urea,......... Uric acid and mucus, ...... Animal extract and ammoniacal salts, Fixed alkaline salts, ....... Earthy salts, ........ Loss,......... 1000-00 352. The following analyses of diabetic urine will serve to illustrate its usual composition. Analyses I & II. (Simon). I. H. Specific gravitu,.......1018 1016 Water, . '........957-00 960-00 11* 126 quantitative analysis Solid constituents,.......43#00 Urea, ........ traces Uric acid, ........ traces Sugar,........39-S0 Extractive matter and soluble salts, . . . 2-10 Earthy phosphates,......0-52 Albumen, ........ traces Analyses III, IV, & V. (Dr. Percy.) Specif c gravity, Water, Solid constituents, Urea, Uric acid, Sugar, . Extractive matters and) soluble salts, . J Earthy phosphates, III. 1042 894-50 105-50 12-16 0-16 40-12 53-06 IV. 1035 918-30 81-70 30-32 40-00 7-99 traces 25-00 6-50 0-80 traces v. 1039 898-90 101-10 2-39 0-26 not isolated 17-15 79-10 32-59 1-30 19-52 0-09 Analysis VI. (Bouchardat.) Water,.........837-58 Solid constituents,.......162-42 Urea ........8"27 Uric acid,........not isolated Sugar........134-42 Extractive matters and soluble salts, . . . 20-34 Earthy phosphates,......0.38 CHAPTER VIII. quantitative analysis of albuminous urine. 353. In the quantitative analysis of albuminous urine, it is usual to estimate the following ingredients; though for many purposes it is sufficient merely to determine the pro- portion of albumen, either with or without that of the urea : 1, water; 2, urea; 3, albumen, with traces of uric acid ;] 4 vesical mucus; 5, animal extractive and ammoniacal salts ; b, fixed alkaline salts; and 7, earthy salts. 354. Treatment of the portion A.—Two portions of the urme, marked respectively A and B, each weighing 500 1 Or the uric may be estimated separately; see paragraph 363. of albuminous urine. 127 grains, are to be evaporated to dryness on a water-bath.1 The portion A will serve for the estimation of the urea; and the portion B for that of the other substances above enu- merated. 355. The residue left after the evaporation of A, is treated with hot alcohol, to dissolve out the urea. The alco- holic solution is evaporated to dryness on a water bath, and redissolved, as far as it is capable, in hot distilled water; the aqueous solution thus obtained is evaporated to a small bulk, and mixed with pounded oxalic acid in the manner described in the analysis of diabetic urine (342). The oxalate of urea is afterwards decomposed by means of car- bonate of lime in the manner already detailed; the weight of the urea obtained being multiplied by two, in order to represent the proportion of urea in 1000 grains of the urine. 356. Treatment of portion B.—The residue left after the evaporation of B, is noiv to be examined. When it has ceased to lose Aveight by exposure on the Avater-bath, the weight of the residue is to be noted ; and the loss Avhich it has sustained during eA'aporation, multiplied by two, will represent the amount of avater in 1000 grains of the urine. 357. The dry residue, Avhen cold, is to bo carefully re- duced to poAvder in a clean dry mortar, Avhich should be placed on a large sheet of white paper, in order to catch any particles that may be projected out of the mortar during the pounding. The poAvder is to be boiled with distilled Avater, Avhich will dissolve out the urea, animal extractive, and soluble salts ; leaving an insoluble residue of coagu- lated albumen, uric acid, mucus, and earthy salts. The mixture is then filtered. The solution thus obtained Ave Avill call M, and the insoluble matter N. 358. The solution M is to be evaporated to dryness on a Avater-bath, and subsequently examined in the manner de- scribed beloAV (361). While the evaporation is going on, the insoluble matter N may be operated on (359). 359. The insoluble matter N, consisting of albumen, uric acid, mucus, and earthy salts, is to be carefully detached from the filter while still moist. It "is then Avarmed for a 1 If it is intended to estimate the uric acid separately, a third portion of urine, weighing 1000 grains, will also be required (363). 128 quantitative analysis few seconds with a little dilute nitric acid (consisting of one part of strong acid, and about six parts of Avater), and well stirred with a glass rod, in order to dissolve out the earthy phosphates. The insoluble portion is to be washed with a little warm water (360), and the acid solution, together with the washings, then evaporated to dryness on a water- bath. The dry residue is weighed, incinerated, and Aveighed again; when the weight of the incombustible matter multi- plied by two, will represent the proportion of earthy phos- phates in 1000 parts of the urine ; while the loss Avhichthe mixture sustained during incineration, also multiplied by tAvo, will represent the amount of VESICAL mucus. 360. The portion of N which proved insoluble in the di- lute nitric acid (359), consisting of albumen with probably a little uric acid, is to be dried on a Avater-bath, and weighed. The weight, multiplied by two, will represent the proportion of albumen and uric acid in 1000 grains of the urine. This residue should be tested for uric acid, by means of nitric acid and ammonia (23); and if it appears to be present in any considerable quantity, it may be esti- mated from a separate portion of urine (363). 361. The evaporated residue left by the solution M (358), containing the urea, animal extractive, and soluble salts, must now be examined. After its Aveight has been ascer- tained, the dry residue is to be gently ignited, until the incombustible matter becomes white or pale-gray. The ash thus obtained is then weighed; and its weight, multiplied by two, will represent the proportion of fixed alkaline salts in 1000 grains of the urine.1 362. The loss of weight which the residue sustained during incineration (361) being due to the combustion of the urea and animal extractive, and the volatilization of the ammoniacal salts, derived from 500 grains of urine; we obtain, by doubling it, the amount of those substances con- tained in 1000 grains. From this we deduct the proportion of urea, which Ave have already ascertained (355), and the difference will represent the amount of animal extractive and ammoniacal salts, contained in 1000 grains of the secretion. 1 During this ignition, traces of the alkaline chlorides are always volatilized, causing a slight loss. OF ALBUMINOUS URINE. 129 363. If it is required to estimate the proportion of uric acid in albuminous urine, which, however, is seldom neces- sary, since there is not often more than a small trace of it present, a separate portion of urine must be used for the experiment. For this purpose, 1000 grains are to be boiled for about a quarter of an hour, and filtered from the coagu- lated albumen. The filtered liquid is then concentrated to about one-fourth its bulk, by evaporation on a water- bath, and, after the addition of a few drops of hydrochloric acid, set aside in a cool place for forty-eight hours. The uric acid, if present in any notable quantity, will gradually crystallize out, mixed possibly with traces of hippuric acid (25), which may be Avashed out Avith a little alcohol (28). The weight of the residue will then, after drying on a water-bath, represent the proportion of the acid in 1000 grains of urine. 364. Thus Ave shall have completed the analysis, having determined the proportion of the several ingredients pro- posed ; which, when added together, should amount to a fraction less than 1000 grains, viz., Water, ....... Urea, ........ Albumen, ....... Cric acid, ....... Vesical mucus, ...... Animal extractive and ammoniacal salts, . Fixed alkaline salts, ..... Earthy salts,...... Loss,........ 1000-00 365. The folloAving analyses of albuminous urine, in cases of Bright's disease, will serve to show its usual composition. Analyses I & II. (Simon.) Specific gravity, Water, Solid constituents, Urea, Uric acid, Fixed salts, . Extractive matters, Albumen, I. II. 1014 1022 966-10 933-50 33-90 66-50 4-77 10-10 0-40 0-60 8-04 10-00 2-40 ----- 1800 33-60 130 ANALYSIS OF ALBUMINOUS URINE. Analysis III. (Dr. Percy.) Specific gravity,........1020 Water,..........9I6-S2 Solid constituents, ....... 53-18 Urea, ......... 7-fiH Uric acid and indeterminate animal matter, . . 17*52 Fixed soluble salts, ....... 5-20 Earthy phosphates, . . . . . . . 0*14 Albumen, ........ 2264 PART II. CALCULI AND CONCRETIONS. CHAPTER I. URINARY CALCULI. SECTION I. 366. Urinary calculi are composed, in the great majority of cases, of substances which are contained in healthy urine, such as uric acid, urate of ammonia, and the phosphates of lime and magnesia; they are, hoAvever, occasionally com- posed of substances which are met with only in morbid urine, such as oxalate of lime, cystine, &c. Other substances also, Avhich may strictly be called accidental, are occasion- ally contained in calculi; such as fragments of sand, or other hard bodies, which have occasionally found their way into the kidneys or bladder, and there formed nuclei, round which the earthy phosphates, or other matters, have gra- dually been deposited. Calculi always contain, in addition to the ingredients of Avhich they mainly consist, more or less animal matter; such as dried blood and urine, vesical mucus, &c. 367. Calculi are found to-consist occasionally almost en- tirely of one ingredient only, but more frequently of tAvo or more different constituents arranged together in irregular concentric layers. On this account it is impossible to deter- mine, with any degree of certainty, the nature of the mass of a calculus, by merely examining the external coating, since the more central portion may be of a nature Avholly different. The best Avay is to divide the calculus into two 132 URINARY CALCULI. equal parts, which is easily done by carefully cutting it through the centre with a fine saw. Fig. 51 represents a mixed calculus divided in this manner; the darker layers consisted, in the specimen from Avhich the drawing A\as made, of oxalate of lime, and the lighter rings of uric acid. When a calculus is thus found on examination to consist ap- parently of two or more kinds of matter, fragments of each kind should be carefully detached and separately examined (411). Fig. 51. Fig. 52. Alternating Calculus. Uric Acid Calculus. SECTION II. Uric (or Lithic) Acid (C^H.O,.). 368. Uric acid calculi are usually smooth or slightly tuberculated on the surface (Fig. 52), and of colors vary- ing from pale yelloAvish fawn to reddish brown. When sawn through, the layers will generally be found to be tolera- bly regular, though of different thicknesses, and nearly paral- lel to the outline of the section. This is the most common of all the urinary calculi. 369. Heat a small fragment of the calculus with the blowpipe on platinum foil; it immediately blackens, OAving to the charring of the animal matter, emitting, at the same time, a disagreeable smell, resembling that of burnt feathers, mixed with that of hydrocyanic acid (H,C2N), which, to- gether with carbonate of ammonia, and some other com- pounds, is formed during the decomposition. If the heat 1 A small fragment of the calculus, about the size of a pin's head is generally sufficient for each experiment, and will be found more con- venient in practice than a larger quantity. URINARY CALCULI. 133 be continued, the charred residue is gradually consumed, leaving only a slight trace of ash, which is usually alkaline to test paper, consisting of phosphate or carbonate of soda. Traces of the earthy phosphates, also, are almost ahvays to be found in this and most other varieties of calculi. 370. Uric acid is insoluble in water, and nearly so in dilute acids (22). 371. A little of the calculus in powder is placed in a drop or tAvo of tolerably strong nitric acid, in a watch- glass, or on a strip of glass; it dissolves with effervescence, carbonic acid and nitrogen being given off, and a mixture of alloxan (C8N2II4019), alloxantine (C4II3N203), and some other compounds remains. This is evaporated nearly to dry- ness at a gentle heat, when a red residue is left, Avhich, when cold, and treated with a drop of ammonia, or exposed to ammoniacal fumes, becomes purple, OAving to the forma- tion of murexide (C12N51IC08). 372. Uric acid dissolves in a solution of potash, leaving only a feAv shreds of animal matter (366); and when the mixture is warmed, no smell of ammonia is perceptible, thus differing from the urate of ammonia (377). On neu- tralizing the alkaline solution with any acid, as hydro- chloric, a white precipitate of pure uric acid is thrown doAvn, which, Avhen separated by filtration, may be tested with nitric acid and ammonia, as described in 371. KO, C^V^O^ECl^KCl+EO+C^Jifia- 373. If the precipitated uric acid be examined under the microscope, it will be found to consist of minute crystals, having the form shoAvn in Fig. 3, page 6. SECTION III. Urate (or Lithate) of Ammonia (NH4O,C10N4H4O6). 374. It is not often that we meet with calculi composed wholly of urate of ammonia, that substance being more commonly found alternating with uric acid, earthy phos- phates, or other matters. These calculi are generally small in size; smooth, or slightly tuberculated (Fig. 53); and pale slate or clay-color, sometimes inclining to brown. The concentric layers are usually thinner, and less dis- tinctly marked, than those of uric acid. 134 URINARY CALCULI. 375. When heated before the blowpipe, urate of ammonia usually decrepitates, gradually disappears, and in other respects behaves like uric acid (369). It dissolves tolerably well in hot water; but being insoluble, or nearly so, in cold, is deposited again when the solution cools, as an amorphous precipitate. If a dilute acid, as hydrochloric, be added to a hot so- lution of urate of ammonia, the lat- ter is decomposed, and the uric acid set free; which, being insoluble even in hot water, is precipitated in the form of minute crystals (Fig. 3, page 30). 376. With nitric acid and ammonia, urate of ammonia produces the same results as uric acid (371). 377. Urate of ammonia dissolves readily in a warm solu- tion of potash, giving off at the same time ammoniacal fumes; by Avhich it may be distinguished from uric acid and urate of soda. The addition of a dilute acid to the hot solution causes a crystalline precipitate of uric acid (373). Urate of Ammonia Calculus. SECTION IV. Phosphate of Lime (8CaO,3P05). 378. Calculi of phosphate of lime are most commonly smooth and even polished on the sur- face. The concentric laminae are generally arranged with considera- ble regularity (Fig. 54); and when the calculus is broken, these sepa- rate from each other Avith great facility, forming detached crusts. The color is usually pale fawn or stone color. 379. Before the bloAvpipe, it chars, owing to the presence of a little animal matter; and gradually becomes white, as the carbonaceous matter burns aAvay. It is almost infu- sible, requiring for its fusion so intense and prolonged a heat, that feAv can succeed in fus'ins: it. Phosphate of Lime Calculus. URINARY CALCULI. 135 380. The residue, after ignition, is neutral to test paper. 381. It is soluble, without effervescence, in dilute nitric or hydrochloric acid (49). 382. Divide the solution in nitric acid, formed in the last experiment, into three parts, and neutralize the first portion with ammonia; the phosphate of lime is again thrown down unchanged, in the form of a gelatinous amor- phous precipitate (49). 383. To the second portion of the acid solution, add a drop or two of nitrate of silver, and cautiously neutralize the mixture with dilute ammonia ; a pale yelloAV precipitate of phosphate of silver (3AgO,P05) will be thrown down, Avhich is soluble both in ammonia and nitric acid. 384. To the third portion of the nitric acid solution, add dilute ammonia until it is nearly neutral, taking care that it is not added in sufficient quantity to cause the precipita- tion of the phosphate of lime (382). Test the solution with oxalate of ammonia, Avhich throws down a copious Avhite precipitate of oxalate of lime (47 b). 385. If a little of the pounded phosphate of lime be mixed Avith about twice its bulk of the double phosphate of ammonia and magnesia, or triple phosphate (MgO,NII40, IIO,P05), and heated before the blowpipe on platinum wire, it readily diffuses. The fusible calculus is composed of a similar mixture of the two salts (391). SECTION V. Phosphate of Ammonia and Magnesia or Triple Phosphate (MgO,NH,0,HO,P05). 386. Calculi composed entirely of triple phosphate are of someAvhat rare occurrence ; but mixed, or alternating with other matters, and indeed constituting the great bulk of the concretion, this substance is very common. ^ Such calculi are sometimes found to have been deposited in con- centric layers, and sometimes consist of an aggregated mass of prismatic crystals. They are usually nearly colorless, or slightly tinged Avith drab or stone color. The surface is most commonly rough and uneven, and often coA'ered Avith small shining crystals. 387. The triple phosphate, when heated before the blow- 136 URINARY CALCULI. pipe, chars, and gives off the smell of ammonia ; swells up, gradually becomes gray as the carbonaceous matter is con- sumed, and ultimately fuses. 388. It is almost insoluble in water, but if boiled, a small quantity will be found to dissolve. 389. It dissohres readily in dilute hydrochloric and most other acids, and is again thrown doAvn in the form of a crys- talline precipitate, when the solution is neutralized with ammonia. If the precipitate thus obtained be examined under the microscope, it will be found to consist of Avell- defined crystals, which, if the solution has been supersatu- rated Avith the ammonia, are stellate (Fig. 10, page 39); but if merely neutralized, they are prismatic (Fig. 8, page 390. When heated Avith a solution of potash, it is decom- posed, the potash combining with the phosphoric acid, and setting free the ammonia and the magnesia. The former volatilizes, and may be detected by the smell, while the magnesia is precipitated (49). MgO, NH40, HO, V05+2KO*=2KO, HO,P05 + NH3+ MgO, HO. SECTION VI. Fusible calculus, which is a mixture of Phosphate of Lime (8CaO, 3POs), and the Double Phosphate of Ammonia and Magnesia (MgO,NH40,HO,P05). 391. The fusible matter of which this form of calculus is composed, is, next to uric acid, the most common of the ingredients of calculi. It sometimes con- stitutes the entire mass of the calculus ; is also frequently found alternating Avith other ingredients ; and very com- monly forms the outer crTist of calculi composed of uric acid and other mat- Fusibie calculus. ters. Fusible calculi are generally oval or irregular in form (Fig. 55); Avhite, soft, and friable, resembling chalk; though occasionally they are compact and hard. 392. This calculus is chiefly characterized by the readi- ness with which it fuses before the blowpipe, without being consumed; in Avhich respect it differs from all other kinds URINARY CALCULI. 137 of calculus. During the ignition, the ammonia and Avater are expelled, leaving a mixture of the phosphates of lime and magnesia. 393. If a portion of the calculus be dissolved in dilute hydrochloric acid, nearly neutralized Avith ammonia, and treated with oxalate of ammonia, the lime is separated as oxalate (47, b), while most of the magnesia remains in solution. 394. If the ammonia be added to the acid solution of the calculus (393) until it causes a precipitate, the mixed phos- phates of lime, and of ammonia and magnesia, are thrown doAvn. When examined under the microscope, the first appears as an amorphous poivder, the latter distinctly crystalline (43). SECTION VII. Oxalate-of-lime Calcidus (CaO,C203). 395. Calculi are not unfrequently met with, composed almost entirely of oxalate of lime; but more. commonly the nucleus will be found to consist of uric acid or urate of lime. Oxalate-of-lime calculi are usu- ally very dark in color, either brown or Fi&-56- dark oliAre, or a kind of dirty purple. Their surface is much more irregular and rugged than other descriptions of calculi; and Avhen sawn asunder, they exhibit an irregular and angular struc- ture, as shoAvn in figure 56. From ^^-2^^^ their resemblance to the fruit of the oxalate of Lime calculus. mulberry, this ATariety is commonly known as the mulberry calculus. 396. There is also another form in which oxalate-of-lime calculi are occasionally met Avith, commonly called hemp- seed calculi. These are small, round, or OAral, and very smooth and polished on the exterior; they generally con- tain also a little urate of ammonia. The general form and appearance of these oxalate-of- lime calculi are usually so peculiar and characteristic, that they may be, in most cases, easily recognized by simple in- spection. 12* 138 URINARY C A L (' U L I. 397. Pounded oxalate of lime dissolves Avithout efferves- cence in dilute nitric and hydrochloric acids, and is again thrown down unchanged, in the form of a Avhite precipitate, Avhen the acid solution is neutralized Avith ammonia. Occa- sionally a little carbonate of lime is found mixed with the oxalate, in Avhich case, slight effervescence will, of course, take place on the addition of the acid. 398. Oxalate of lime is insoluble in acetic and oxalic acids. 399. When heated before the blowpipe, it blackens, and gives off a disagreeable smell, resembling that of burnt feathers. If the heat be continued a short time, the residue becomes white, and then consists of carbonate of lime, into which the oxalate is converted ; carbonic acid being also, Avith other gaseous matters, at the same time given off. CaO,C203+0=CaO,C02-r-C02. 400. Treat the residue formed in the last experiment with dilute hydrochloric acid: it readily dissolves, Avith effervescence, shoAving that it has been changed into the carbonate. 401. The solution of chloride of calcium (CaCl) thus formed, may be neutralized with ammonia, and tested for lime Avith oxalate of ammonia, which will throw down the oxalate of lime (CaO,C203+2Aq), in the form of a Avhite precipitate (171). 402. If the oxalate of lime be kept intensely heated for some little time, the carbonate Avhich is at first formed is reduced to the state of caustic lime (CaO) ; which may be proved by placing the residue, when cold, on a piece of moistened turmeric paper, the yellow color of which will be turned to brown. SECTION VIII. Urate (or Lithate) of Lime (CaO,C10N4II4O6). 403. This substance, though never found composing entire calculi, is not unfrequently present in small quanti- ties in concretions Avhich consist chiefly of uric acid, oxalate of lime, or other matters. 404. Urate of lime is nearly insoluble in cold water, but dissolves in hot, though somewhat less readily than urate TABULAR VIEW OF THE DISTINCTIVE CHARACTERS OF CALCULI. (SLIGHTLY ALTERED FROM SCHARLING.) SPECIES. FORM. COLOR. TEXTURE. SURFACE. SIZE. CHEMICAL AND BLOWPIPE CHARACTERISTICS. FORM OF CRYSTALS. EXTERNAL. INTERNAL. COT. FRACTURED. Uric acid. C10N4U4O6 Ovoid, or sphe-roid,when single. Forming facettes and angles when numerous. Yellowish fawn; reddish brown; color of maho-gany, never gray or white. Dense, compact, and frangible. Smooth, or finely tuberculated. Smooth and po-lished, formed of concentric layers and striae. Crystalline when pure; earthy when mixed with other ingredients. From that of a pea to that of a duck's egg. 1-276 to 1-786 Combustible; exhales odor of burnt bone and hydrocyanic acid before blowpipe. Soluble in nitric acid, yielding pink stain on evaporation, changed to purple by Soluble in solution of caustic potash. Rhomboid, lozenge-shaped, plates, &c. Fig. 30. Urate of ammonia. NH4O,C10 NH406 Compressed spheroid or amygdaloid. Clay colored; slate colored; " couleur de cafe au lait." Frangible. Finely tubercu-lated. Smooth and even; thin concentric layers. Finely earthy; granular, like compact lime-stone. From that of a pea to that of a marble. 1-225 to 1-720 Combustible; decrepitating and yielding strong odor of ammonia before blowpipe. Soluble in nitric acid, yielding uric acid reaction. Soluble in boiling water, and carbonated alkalies. Exhales vapor of ammonia when heated with potash. Amorphous, or minute globules, Fig. 11. Phosphate of lime. 8CaO,3P05 Spheroidal. Pale brown, or grayish white. Compact. Smooth, polish-ed and porce-laneous. Laminated; the layers easily se-parable; striated perpendicularly to the surface. Semi-crystalline; conchoid al. Moderate. Incombustible; infusible except under intense heat before blowpipe. The blowpipe residue soluble in hydrochloric and nitric acids; reprecipitated by The blowpipe residue insoluble in acetic or very dilute sulphuric acids. The blowpipe residue insoluble in water, not alkaline. Amorphous. Triple phosphate. MgO,NH40, HO,P03 Compressed spheroid; compressed ovoid; pyriform; reniform. Nearly white. Friable. Powder not gritty. Uneven; studded with sharp shining crystals. Earthy, pulveru-lent; crystalline; not striated. Clusters of crys-tals imbedded in friable matter, or lining the walls of cavities and fissures. Usually large. Incombustible; fuses with difficulty, evolves ammonia before blowpipe. Soluble in dilute hydrochloric, nitric, and acetic acid?. Precipitable without decomposition by ammonia from acid solution. The blowpipe residue insoluble in water, and not alkaline. The blowpipe residue soluble without effervescence in acids; yields crystalline precipitate when ammonia is added to the acid solution in excess. Stellate, prismatic. Fig. 7. Fusible. Very irregular; round ; pyriform; lobulated. Quite white. Very white, leaving a chalk-like streak. Spongy, rough, not tuberculated nor spinous. Indistinct layers united by crys-tals of triple phosphate. Earthy, with clusters of triple phosphate sprin kled throughout. Generally large, fre-quently very large. 1-140 to 1-470 Incombustible; speedily and readily fusible into a white bead before blowpipe. The blowpipe residue soluble in acids without effervescence; reprecipitated by ammonia. The blowpipe residue insoluble in water, and not alkaline. Oxalate of lime. CaO,C203 | Deep brown; olive, or black-Spheroidal, j ish green; dull octohedral, i purple, Fome-cubical. times whitened with the phos-phates. Very compact and dense. Spinous and rugged. Eccentric lami-na-, arranged like fortification agate, smooth and polished. Uneven, splintery. Moderate. 1-428 to 1-976 Incombustible and infusible; expands into a white efflorescence before blowpipe. Soluble slowly in nitric and hydrochloric acids, without effervescence. The blowpipe residue soluble with effervescence in acids. The blowpipe residue insoluble in water, yielding, after strong ignition, an alka-line reaction. Acute octohe-drons. Fig. 23. Cystic oxide. C6NH604S2 Oval oblong. Tawny yellow; becoming green in time. o„^a. , „__- Covered with Consistence of 1 .u . , ., i smooth tuber-wax, resembles ' Ta n, a**™ peannce. [ jections. Confusedly ra-diated, but not laminated. Exhibits a pecu-liarly refractive lustre. May be scraped into a white powder. Moderate. Combustible ; yields an odor like that of sulphuret of carbon before blowpipe. Soluble in liquid ammonia, fixed alkalies, and many acids. The ammoniacal solution yields on evaporation hexagonal plates. Insoluble in carbonate of ammonia, acetic, citric, and tartaric acids. Yields a brown stain when dissolved in excess of nitric acid and evaporated. Hexagonal or roundish tables, opaque in the centre. Fig. 26. Carbonate of lime. CaO,C02 Spherical. White. I'riible. Smooth. Very Small. Incombustible and infusible. Soluble in acids with effervescence. The blowpipe residue, after strong ignition, soluble in acids without effervescence. Xanthic, or uric oxide. C5N.2H202. Ovoid, flattened at the sides. Brownish red, resembling that n . j Smooth. Compact and ,!<1Kinous iustre hard" when rubbed. Laminated, nei-ther fibrous nor crystalline. Partly brown and lustrous, partly white and earthy. Moderate. Combustible; splitting into fragments, exhales peculiar foetid odor before blowpipe. Soluble, without effervescence, in nitric acid; yielding lemon-yellow stain on evaporation. Soluble in strong sulphuric sicid. not precipitable in water. Insoluble in solution of carbonate of potash. Amorphous. (To face page 139.) URINARY CALCULI. 139 of annnonia (37")). The hot aqueous solution deposits it again on cooling, generally in the form of minute needle- shaped crystals. 40o. Like the other urates, it is decomposed by hydro- chloric acid. If the acid be added to a hot aqueous solution of the salt, a crystalline precipitate of uric acid is thrown doAvn (377, 373), and chloride of calcium remains in solution. CaO,C10N.1HiO0+^CT=CaCZ-r.^O-l-C10N4II1O6. 406. When tested with nitric acid and ammonia, in the manner described in paragraph 371, urate of lime behaves like uric acid and the other urates, yielding the rich purple color of murexide. 407. As this is the only salt of lime found in calculi which is soluble in hot water, it may be supposed to be present Avhen, after boiling a little of the pounded calculus in water, the hot aqueous solution gives a white precipitate of oxalate of lime (CaO,C203+2Aq), when tested with oxalate of ammonia (401). SECTION IX. Cystine (GiNHeO^). 408. Calculi of cystine arc of rather rare occurence. They are usually more or less crystalline in structure, not deposited in laminae, soft, and of a pale brownish-yellow or greenish tint. Small calculi composed almost exclusively of this substance have been occasionally found in the dog. 409. The chemical characters of cystine, and the methods of distinguishing it by tests, will be found described in the chapters on urine (172, 209, &c.) . 410. The annexed table shows the principal peculiarities of the several varieties of urinary calculi. CHAPTER II. JIALITATIVE EXAMINATION OF URINARY CALCULI, THE COMPOSITION OF AVHICH IS UNKNOAVN. 411 When a calculus has to be examined with a view to certaining the nature of its ingredients, a very few simple 140 ANALYSIS OF CALCULI. experiments, conducted on some such plan as the folloiving, will generally furnish the required information. The cal- culus should first be saAvn through, and the loose dust gently brushed away. If the several laminno of Avhich the mass is composed appear to be homogeneous, and to con- sist of the same kind of matter, a small fragment may be taken from any part of it for examination (412); but if, as is more frequently the case, there appear to be tAvo or more different kinds of matter contained in the several layers (367), fragments of each of them should be carefully detached from the mass, and examined separately in the following manner. 412. Place a small fragment on platinum foil, and heat it to redness before the blowpipe, until the blackness of the charred animal matter disappears. Observe Avhether,— (a) It burns aavay, leaving only a minute trace of ash (413); or (b) It proves incombustible, avithout materially lessening in bulk (414); or (c) It is partially consumed, leaAring, however, a con- siderable residue of incombustible matter (415). 413. If it burns aavay, leaving only a minute trace of incombustible ash, it is probably either uric acid, urate of ammonia, or cystine ; or possibly a mixture of two or more of them. See 416-419. 414. If it is incombustible, not materially lessening in bulk during the ignition, it is probably either phosphate of lime, triple phosphate, fusible matter (391), oxalate of lime (converted into carbonate by the heat), urate of lime (also converted into carbonate); or perhaps tAvo or more of those substances mixed together. See 420-425. 415. If the fragment is partially consumed, it will probably be found to consist of a mixture of one or more of the combustible substances mentioned in paragraph 413, with some of those enumerated in paragraph 414. See 426-428. Examination of Combustible Calculi (413). 416. If the calculus (in poAvder) is found to be insoluble IN AVARM AVATER ; SOLUBLE IN SOLUTION OF POTASH, without ANALYSIS OF CALCULI. 141 the evolution of ammonia; and to form, when tested with nitric acid and ammonia, a purple residue ; it is probably uric acid (370, 372, 371). (Confirm 373.) 417. If it is found to be soluble in hot avater ; soluble IN solution of potash, with the evolution of ammoniacal fumes; and to yield, Avith nitric acid and ammonia, a purple residue ; it is probably urate of ammonia (375, 377, 376). (Confirm 373.) 418. If it is found to be insoluble in warm water : readily soluble in ammonia ; the ammoniacal solution yielding, on sIoav evaporation, hexagonal crystalline plates, it is probably cystine (174, 173). (Confirm 174, 271, 273.) 419. If it is suspected that more than one of the above substances are present, a little of the poAvder may be boiled Avith Avater, and if any portion remains undissolved, the mixture filtered while hot. (a) If the clear filtered liquid deposits, on cooling, an amorphous precipitate, urate of ammonia is probably present (375). (Confirm 417.) (b) If the insoluble portion gives a purple color when Rested Avith nitric acid and ammonia, URIC acid is probably present (371).- (Confirm 416.) (c) If the insoluble portion is wholly or partially soluble in ammonia ; the ammoniacal solution yielding, on evapo- ration, hexagonal plates, cystine is probably present (173). (Confirm 418.) Examination of Incombustible Calculi (414). 420. If the matter of the calculus is infusible before THE BLOWPIPE ; SOLUBLE IN DILUTE HYDROCHLORIC ACID ; the acid solution of the substance after ignition, yielding, when neutralized with ammonia, an amorphous precipi- tate, it is probably phosphate of lime (379, 381, 382). (Confirm 383, 384.) 421. If it is tolerably fusible before the bloAvpipe; soluble in dilute hydrochloric acid ; the acid solution giving, Avhen neutralized with ammonia, a crystalline pre- cipitate, it is probably triple phosphate (387, 389). (Confirm 390.) 142 ANALYSIS OF CALCULI. 422. If it is readily fusible before the blowpipe; soluble in dilute hydrochloric acid ; the acid solu- tion yielding, when supersaturated with ammonia, a pre- cipitate, Avhich, Avhen examined under the microscope, is found to contain both amorphous particles and also crystalline stell^, it is probably composed of the mixed, or fusible phosphates (392, 394). (Confirm 393.) 423. If the substance, previous to ignition, is soluble avithout effervescence in dilute hydrochloric acid; the acid solution yielding a white precipitate avhen neu- tralized avith ammonia ; and after gentle ignition, is soluble avith effervescence in the dilute acid; the acid solution, moderately diluted, now yielding no precipitate when neutralized Avith ammonia, it is probably oxalate of lime (397, 400, 401). (Confirm 398, 402.) 424. If the hot aqueous solution, formed by boiling a little of the pounded calculus Avith water, gives a avhite precipi- tate avith oxalate of ammonia, the presence of urate of lime is indicated (407). (Confirm 404, 405, 406.) 425. If it is suspected that more than one of the above substances are present in the portion of calculus under ex- amination, it may be gently ignited, and then treated with" dilute hydrochloric acid. (a) If effervescence ensues (the calculus, previous to ignition, not causing effervescence with the acid), oxalate (or possibly urate (c) of lime is probably present (397, 400). (Confirm 423.) (b) Supersaturate the acid solution with ammonia; and if any precipitate is produced, examine it under the micro- scope for PHOSPHATE OF LIME and TRIPLE PHOSPHATE (38'? 389). (Confirm 420, 421.) ' V "' _ (c) Boil a little of the pounded calculus previous to igni- tion^ with water ; and test the hot aqueous solution thus obtained, Avith oxalate of ammonia. If a WHITE precipi- tate is produced, urate of lime is probably present (407). (Confirm 424.) Examination of Partially Combustible Calculi (415). 426. When the calculus, or any portion of it, is found to be partially consumed when ignited, it is probably a mix- biliary calculi. 143 ture of one or more of the combustible matters enumerated in paragraph 413, associated Avith one or more of the incom- bustible ingredients mentioned in paragraph 414. 427. A portion of the calculus, previous to ignition, may first be examined for the organic or combustible ingredients, in the manner described in paragraph 419, a, b, & c. 428. Another portion of the calculus may then be gently ignited on platinum foil, and the residue examined for the inorganic matters, according to the directions given in para- graph 425, a, b, & c. CHAPTER III. BILIARY calculi or gall-stones. 429. Biliary calculi are usually of a pale yellow or brownish color; soft, soapy to the touch, and easily crushed into small fragments by pressure; and the texture of the mass is in most cases deci- ris-67- dedly crystalline. The size most commonly ^^ met with is about that of a pea; but they are frequently found much smaller, and oc- casionally almost as large as a pigeon's egg. The form is generally irregular and some- Biliary calculi. Avhat angular, as shoAvn in Fig. 57. 430. They usually contain from fifty to eighty per cent. of cholesterin (C3cH320); the rest of the concretion being made up of biliary resin and coloring matter, mucus, and traces of other animal matters, with a small quantity of inorganic salts. The composition of three specimens ana- lyzed by Brande Avas as folloAvs : i. n. in. Cholesterin,......81-25 69-76 81-77 Biliary resin,......3*12 566 3-83 Bile pigment, ...... 9"38 11-38 7"57 Albumen and salts extractible by water, . ---- ---- 383 Biliary mucus, ...... 6-25 13-20 ---- 431. Heat a small fragment of gall-stone on platinum foil; it Avill burn with a bright but smoky flame, leaving a small fixed residue, consisting of inorganic salts. 144 gouty concretions. Fig. 58. 432. When coarsely pounded, it dissolves readily in boil- ing alcohol; and on cooling, the cholesterin crystallizes out in the form of fine scaly crystals (Fig. 58), Avhile the biliary resinous and coloring matters remain in solution, giving the liquid a yelloAvish tinge. 433. It is insoluble in dilute nitric and hydrochlo- ric acids. 434. It is insoluble also Cholesterin. jn a solution of potash; thus differing from other fatty and oily substances, which cho- lesterin resembles in many respects. CHAPTER IV. GOUTY CONCRETIONS. 435. These earthy concretions, which form in the joints of gouty persons, are usually white, or nearly so, soft and friable, closely resembling chalk in appearance, and hence commonly known as chalk stones. They seem to vary a good deal in composition; but in the great majority of those which have been analyzed, urate of soda (NaO,C10N4H4O6) appears to form the principal and most characteristic in- gredient. They contain also a considerable quantity of chloride of sodium and dried cellular tissue; with occa- sionally urate of lime (CaO,C10N4H4O6), phosphate of lime (8CaO,3P05), and chloride of potassium. The presence of a large quantity of uric acid may be shown by the forma- tion of the purple-colored murexide, when a little of the concretion, in poAvder, is treated with nitric acid and am- monia, in the manner described in paragraph 371. Qualitative Examination of Gouty Concretions. 436. Reduce the concretion intended for analysis to tole- rably fine poAvder, and digest it in cold Avater to dissolve GOUTY CONCRETIONS. 145 out the chlorides of sodium and potassium. Filter the solution from the insoluble portion, which must be reserved for subsequent examination (440). 437. Test a few drops of the aqueous solution thus formed, with nitrate of silver. A white curdy precipitate, which is readily soluble in ammonia, but insoluble in nitric acid, Avill show the presence of chlorine (chloride of so- dium) (41, a). 438. Mix the rest of the aqueous solution with bichlo- ride of platinum; evaporate the mixture to dryness, or nearly so, on a water-bath; and observe the yellow needle- shaped crystals of the double chloride of sodium and pla- tinum (NaCl,PtCl2), shoAving the presence of soda (chloride of sodium) (41,/). 439. Add a little alcohol to the evaporated residue, and observe whether any small sandy-looking crystals remain undissolved, indicating the presence of potash (41, e). 440. The portion Avhich proved insoluble in cold water (436), may noAv be treated Avithhot water, and gently boiled Avith successive small quantities of the liquid as long as anything appears to dissolve. The urate of soda is thus slowly dissolved, together Avith any urate of lime that may be present (97, 404). The matter which proves insoluble in the hot water is to be retained for subsequent examina- tion (444). 441. Hydrochloric acid is now added in slight excess to the hot aqueous solution, and the mixture set aside until it cools, in order to allow the uric acid, which will have been displaced from the soda and lime by the hydrochloric acid (405), to separate completely from the solution. The uric acid is thus precipitated; leaving in solution chloride of sodium, and also, in case any urate of lime Avas present in the concretion, a little chloride of calcium. 442. The mixture thus obtained is filtered. The uric ACID may be examined with the microscope and Avith other tests (37*3, 371); and a little of the aqueous solution may be neutralized with ammonia, and tested for lime "with oxalate of ammonia (171). 443. The rest of the aqueous solution maybe evaporated at a gentle heat with bichloride of platinum; when the vellow needles of the double chloride of sodium and pla- J 13 146 GOUTY CONCRETIONS. tinum (41, /) will prove the presence of a large quantity of soda derived from the urate (435). 444. The remaining portion of the concretion, which resisted the action of the hot water (440) may now be ex- amined. It will probably be found to consist chiefly of dried cellular matter, with perhaps a little phosphate of lime (435). The animal matter may be burnt aAvay, by keeping it at a red heat until the blackness disappears; after which the incombustible residue may be examined in ' the manner described in paragraph 425, and will probably be found to consist of phosphate of lime. 445. The folloiving is an analysis by T. J. Herapath, of some concretions taken from the joints of the fingers of a man suffering from gout: Fat,....... Chloride of sodium, .... Phosphate of soda,. .... Extractive matter,..... Albumen, ...... Urate of soda, with some urate of potash, Urate of lime, ..... Phosphate of lime, .... Perphosphate of iron, .... Water and loss,..... 100-000 PART III. BLOOD. CHAPTER I. HEALTHY BLOOD. SECTION I. General Characters of Blood. 446. The general appearance of blood, as it flows from the vessels through which it circulates in the living body,'kis familiar to every one, as an opaque, slightly viscous fluid, of a more or less brilliant red color; that from the arte- ries being brighter and more scarlet than that from the veins. It has, while warm, a faint though characteristic odor, differing in the blood of different animals, and saline and disagreeable taste. The specific gravity of healthy blood appears to ATary from 1050 to 1058, the average being about 1055. It is ahvays alkaline to test paper. 447. While circulating in the vessels, blood consists of a nearly colorless and transparent liquid, in Avhich float my- riads of minute vesicular bodies or corpuscles, of which by far the greater number are of a bright red color ; and these being so small as to be individually quite invisible without the aid of a tolerably good microscope, give the blood, when seen with the naked eye, the appearance of being a homo- geneous red fluid (451). A few of the corpuscles are color- less, and differ also in other respects from the red ones (464). The fluid portion of the blood, in which the corpuscles float, is usually called the liquor sanguinis. 448. The most remarkable peculiarity presented by the blood, is the spontaneous coagulation Avhich it begins to 148 GENERAL CHARACTERS OF BLOOD. undergo almost immediately after being drawn, gradually separating into a more or less firm and solid red coagulum or clot, consisting of coagulated fibrin mixed with the cor- puscles, and a pale yelloAvish transparent watery liquid, called the serum, holding in solution all the other solid matters of the blood. The* nature and cause of this phenome- non Avill be more fully explained further on (473). The specific gravity of the serum is loAver than that of the en- tire blood, being about 1029. 449. The chemical composition of the blood is highly complex; and though the nature of the principal ingre- dients is noiv tolerably well understood, our knowledge of the more obscure parts of its history is still very imperfect. The folloA\Ting substances appear to enter into its composi- tion (Simon), and probably further researches will reveal the presence of other compounds, and, perhaps, also prove the non-existence of some of those now included in the list. Water, Albumen, Fibrin, Globulin, Haematin, Hasmaphaein, Alcohol extractive (containing traces of urea), Water extractive, Cholesterin, Serolin, Margaric acid, Oleic acid, t Red and white solid fats, containing phosphorus, ' Oxide of iron, Albuminate of soda, Phosphates of lime, magnesia, and soda, Sulphates of potash and soda, Carbonates of lime, magnesia, and soda, Chlorides of sodium and potassium, Lactate and urate of soda, Oleate and margarate of soda, Oxygen, Nitrogen, Carbonic acid, Sulphur, Phosphorus. 450. It will, however, be more convenient for our present purpose, to consider the constituents of the blood as arranged Protein compounds, Coloring matters, Extractive matters, Fatty matters, . . . Saline matters, Gases, HEALTHY blood. 149 in the following manner, the more important substances only being placed separately, and the others being, for the sake of simplicity, grouped together : Water, Red and white corpuscles, Albumen, Fibrin, Alcohol extractive, Water extractive, Oily fats, Crystalline or solid fats. Fixed saline matters. A short description of each of these substances and groups will assist in rendering the subsequent analytical operations, both qualitative and quantitative, more simple and intel- ligible to the student. SECTION II. Blood- Corpuscles. 451. If freshly draAvn blood, previous to coagulation, be examined under the microscope, it will be found to consist of a transparent and nearly colorless fluid, in which float innumerable minute, circular, disk-shaped bodies or cor- puscles, of Avhich by far the greater number appear of a pale yelloAvish color, though they are in reality red ; the paleness of the color being caused by the red rays from each of the corpuscles being spread over so large a surface. It is to these corpuscles that the red color and opacity of the blood are due; the liquor sanguinis, or fluid portion of the blood, in which they float, being nearly colorless and perfectly transparent. 452. These minute bodies, which, when the blood is first draivn, float freely in the liquor sanguinis, occasionally adhere together, forming little aggregations resembling strings of beads or rolls of coin (Fig. 59); this arrangement, hoAvever, is not always permanent, and the corpuscles gradually become again disunited and scattered. The ten- dency to aggregate together is usually greater during the inflammatory state, frequently causing the red corpuscles 150 BLOOD-CORPUSCLES. to collect in irregularly shaped masses, Avhich sink more rapidly than Avhen they are detached from each other. This is one of the causes Avhich tend to produce what is known as the huffy coat, Avhich was formerly supposed to be always indicative of inflammation, but which has since been found to be formed almost Avhenever the fibrin, from whatever cause, coagulates more slowly, or the corpuscles subside more rapidly, than in healthy blood (454, 473). Fig. 59. Fig. CO. Blood-Corpnsclea. magnified Blood-Corpuscles, magnified 400 diameters. 400 diameters. 453. The red corpuscles of human blood vary from Tff2;j5ths to T5sffrjths of an inch in diameter, the average size being about T?sjyffths of an inch. They are nearly circular flat- tened disks, each being slightly depressed and concave in the centre; their thickness is usually about one-fourth or one-fifth of their diameter (Fig. 60).l 454. When, owing to the solidification of the fibrin, the blood coagulates (473), the corpuscles gradually become en- tangled in the network of the solidifying clot, which is, in consequence, of a bright red color ; Avhile the serum, or defi- brinated liquor sanguinis, is left nearly colorless as the clot subsides. In consequence of the corpuscles being slightly heavier than the liquid in which they float, they begin very slowly to subside almost immediately after the blood is drawn ; so that the lower portion of the clot usually contains a larger proportion of them, and has consequently a deeper color than the upper. This is the case to a remarkable ex- tent in certain morbid conditions of the blood, which will be noticed further on (589). 1 For further particulars relative to the structure of the blood-cor- of Ma S aud Bowman'8 Physiological Anatomy and Physiology BLOOD-CORPUSCLES. 151 455. The red corpuscles appear to consist of delicate membranous vesicles, filled with the red fluid to which they oavc their peculiar color, Avhich fluid is supposed to consist of a coloring matter containing a considerable quantity of iron, to Avhich the name of hsematin has been given, associated with a protein compound, in many respects analogous to albumen, and called globulin. The enclosing membrane, which is highly elastic, appears to be composed either of coagulated fibrin, or albumen, or of some other modification of protein closely allied to them. 456. When placed in solutions of different densities, the phenomena of endosmosis and exosmosis presented by the corpuscles are very curious and interesting, and may be seen with great facility with the help of a tolerable micro- scope. As long as the fluid in which they float is of the same density as that which they contain,—such, for in- stance, as the liquor sanguinis,—the corpuscles experience little or no change of form. But if the external liquid is less dense than that contained in the corpuscles, the latter will become more or less distended and globular, owing to the lighter fluid, in obedience to the well-knoAvn laws of endosmosis, passing through the membranous vesicles into the interior more rapidly than the heavier fluid Avithin can pass outAvards. If, on the other hand, the external liquid be more dense than that contained within the corpuscles, the contrary effect will be pro- duced, and the corpuscles will Flg'61' immediately begin to collapse, and assume a Avrinkled appear- ance (Fig. 61). This change of form not unfrequently takes place spontaneously, Ayhile a drop of blood, placed between two surfaces of glass, is being examined under the microscope; especially near the edges, Avhere Biood-corpuscies collapsed, magnified owing to evaporation, the liquid 400 diameters- Avith Avhich the corpuscles are in contact, gradually becomes more concentrated, and consequently more dense. 457. The liquor sanguinis, or fluid portion of the blood, as it exists in the living body, and before it undergoes 152 BLOOD-CORPUSCLES. coagulation, appears to possess the same density as the red fluid contained in the vesicles ; so that, as long as it continues so, no change takes place in the form of the cor- puscles. When, however, the fibrin, which was before dis- solved in the liquor sanguinis, has coagulated, the resulting serum becomes less dense, in consequence of its holding in solution a smaller amount of solid matter (448). The effect of this upon the blood-corpuscles, is to cause them, when in contact with the serum of coagulated blood, gradually to enlarge in size, in consequence of the increased rapidity with which the less dense serum enters through the mem- branous integument. 458. If the red corpuscles be brought in contact with water, the change is extremely rapid ; they instantly swell to a much larger size, the vesicles becoming less and less distinct, until at length, unless the quantity of water is very small, they almost entirely disappear. 459. When, owing to the action of water, or some other liquid of comparatively low specific gravity, the corpuscles have become distended, they may, if the distension has not been alloived to go too far, be again brought back almost to their original size; and even be made to assume a wrinkled appearance, by bringing them in contact with a tolerably strong solution of sugar, or of certain salts, as chloride of sodium, or muriate of ammonia. 460. The corpuscles readily dissolve in a solution of potash, ammonia, acetic acid, and some other fluids. 461. Although we are unable to separate the corpuscles from the blood by filtration, since they pass readily through the pores of the filter, it is found that when mixed with certain strong saline solutions, they are retained by it. A solution of sulphate of soda, for example, having a specific gravity of about 143, when mixed with the blood, effec- tually prevents the passage of the corpuscles through the filter. This remarkable property has been applied by Figuier to the purposes of analysis (582). 462. When blood is alloived to dry at common tempera- tures, and is subsequently moistened, even after the lapse of a considerable time, with some liquid having a specific gravity similar to that of the serum (448), the corpuscles are found to have retained their characteristic form and HEALTHY BLOOD. 153 appearance, and may be readily distinguished under the microscope. This circumstance has been ingeniously applied for the purpose-of solving a question, which in some medico- legal inquiries is one of grave importance, viz., whether the stains found on clothing, or elseAvhere, are, or are not, stains of blood. The methods hitherto devised of identi- fying minute traces of blood by means of chemical tests are very imperfect and unsatisfactory; so that the assis- tance afforded by the microscope here becomes of the highest value. 463. For this purpose, the stain is to be moistened and gently rubbed with a little fresh white of egg, or some other fluid having a specific gravity of about 1030 to 1050. It is then scraped off, and a little of the mixture examined under the microscope Avith a tolerably high power; when, if the stain consisted of blood, the characteristic corpuscles will, in most cases, be distinctly visible. 464. White corpuscles of the Blood.—In addition to the red corpuscles, there are always present in the blood a feAv colorless particles, someAvhat larger than the colored ones, and otherwise differing from them in general appearance and structure (Fig. 62). They are of irregular forms, sometimes spherical, slightly granular on the surface, and appear to be identical or nearly so, with the peculiar corpuscles always present in the lymph and the chyle. When treated with acetic acid, the granular exterior becomes transparent, as in the corpus- cles Of DUS, and One Or more White Corpuscles of the Blood, magni- .r ' . . ■■ -, fied 400 diameters. internal nuclei are rendered visible. 465. The proportion of corpuscles present in healthy blood is usually about 130 parts in 1000 (573). SECTION III. Albumen. 466. This is one of the most important of the constitu- ents of the blood, and, with the exception of the red cor- 154 HEALTHY BLOOD. pusclcs, is present in larger quantity than any of the other solid matters contained in it. It is held in solution in the serum, where it may readily be shown to exist, by gently boiling in a tube a little of the clear colorless fluid from Avhich the coagulated clot of fibrin and corpuscles has sub- sided. As soon as the temperature reaches about 170° the albumen begins to coagulate, and on being boiled for a short time, separates entirely in the insoluble form. 467. It may also be precipitated from its solution in the serum, by adding to the clear fluid a few drops of dilute nitric or hydrochloric acid (136. 141). Acetic acid fails to precipitate it; but if ferrocyanide of potassium be added to the acidified solution, a dense Avhite precipitate is produced, even when the albuminous liquid is very dilute. 468. When gently warmed with strong hydrochloric acid albumen dissolves, forming a purple-colored solution, in Avhich respect it resembles fibrin and casein. 469. When moistened with strong nitric acid, albumen becomes yellow, owing to the formation of xanthoproteic acid (2HO,034N1H24O12), which, together with oxalic acid (HO,C203), ammonia (NH3), nitric oxide (N02), and nitro- gen, is always formed by the action of strong nitric acid on the compounds of protein. A familiar example of this occurs in the yellow stain caused on the skin by nitric acid. 470. It appears from the results of numerous analyses, that the average amount of dry albumen present in healthy blood, is rather more than 70 parts in 1000 (573). 471. The composition of albumen is usually expressed by Mulder's formula (C400H310N50O120S2P); but considerable un- certainty still hangs over the real nature of this class of bodies.1 As the more important peculiarities of albumen 1 The percentage composition of the three so-called protein com- pounds, albumen, fibrin, and casein, is as follows : _, , Albumen. Fibrin. Casein. Carbon,........55-46 54-45 5466 Hydrogen,........7-20 7-07 7-15 Nitrogen,........1648 17-21 15-72 0xygen,........18-27 19-35 21-55 Sulphur,........2-16 1-59 -92 Phosphorus,....... -43 -33 100-00 100-00 100-00 HEALTHY BLOOD. 155 have been already noticed in the chapter on morbid urine (133, 235, &c), they need not be again described. SECTION IV. Fibrin. 472. This substance, of which muscular fibre is chiefly composed, is closely allied in chemical composition and general properties to albumen; and it is, indeed, not im- probable that both are, in their chemical relations, merely modifications of the same compound, Avhich from the cir- cumstance of its being apparently the basis, not only of albumen and fibrin, but also of casein (625) and some other analogous substances, has been called protein, from -pwrebw, I am first.1 473. While circulating in the vessels, the fibrin of the blood is held in a state of solution in the liquor sanguinis; but no sooner is the blood removed from the system, than it begins to separate in a solid state, after which it becomes quite insoluble in Avater. This solidification of the fibrin is the cause of the well-known phenomenon of coagulation, which blood experiences almost immediately after it is draAvn; and although the coagulum or clot contains the blood-corpuscles in addition to the fibrin, these have merely been entangled in the netAvork of coagulating fibrin, and do not themselves play any active part in the process of coagulation. 474. The coagulation of blood may be retarded, and even altogether prevented, by the presence of certain salts and other substances. The alkalies, for example, and their carbonates and acetates, entirely prevent it; and tolerably strong solutions of nitrate of potash, nitrate of lime, muriate of ammonia, and some other salts, retard it for a consider- able time. The latter salt, indeed, gradually dissolves fibrin, after it has been allowed to coagulate. Most of the dilute acids, also, cause blood to retain its fluidity, though it becomes, under their influence, more viscous and syrupy in its consistence. 475. Contact with certain animal membranes also appears to exercise a retarding influence on the coagulation of the 1 See note to 471. 156 HEALTHY BLOOD. blood. When infused into the cellular tissue, it has been knoAvn to continue uncoagulated for some weeks ; and even in a tied artery, it remains some hours Avithout coagulating. 476. It appears from the experiment of M. Denis, that if moist fibrin be digested in a solution of nitrate of potash containing a little soda, at a temperature of about 100° F., it becomes gradually converted into a substance in almost every respect identical Avith albumen; being soluble in water, and coagulable by heat. This change is said to be most readily produced when the fibrin employed in the ex- periment has been obtained from venous blood, by allow- ing it to coagulate spontaneously ; Avhile, if it is separated by agitation, or if the blood be arterial, it scarcely experi- ences any alteration in the saline solution. 477. Pure fibrin may be obtained Avithout difficulty, by receiving the blood, as it Aoavs from the body, in a clean porcelain dish, and stirring it well for some little time Avith a glass rod ; or the blood may be shaken Avith a few small fragments of lead, in a closed glass flask. The fibrin, as it coagulates, collects in loose fibrous masses round the rod or fragments of lead, colored slightly red, OAving to the im- prisonment of a feAv corpuscles Avithin the network of fibrin. These may be removed by tying the coagulum in a piece of fine muslin, and ivashing it under a stream of cold Avater until the mass becomes colorless. In this state, it still con- tains traces of fatty matter and inorganic salts, together with a considerable amount of water. To obtain the fibrin, therefore, in a state of perfect purity, the Avashed coagulum must be dried on a chloride of calcium bath at a temperature of about 250°, and the dry mass then reduced to fine powder in a mortar. The pounded fibrin may aftenvards be Avashed successively Avith alcohol, ether, and dilute hydrochloric acid; and, lastly, macerated with cold or lukeAvarm water, until all the soluble matter is removed; after Avhich it may be dried as before at a temperature of about 250°. 478. If the blood from Avhich Ave wish to extract the fibrin has already coagulated, the clot is first gently pressed betAA-een folds of bibulous paper, in order to squeeze out the greater part of the adhering serum, and then cut into thin shreds with a sharp knife. The finely-divided clot is then washed in a muslin bag under a gentle stream of cold water, HEALTHY BLOOD. 157 until it becomes colorless, by which means the imprisoned corpuscles are washed out of the fibrous mass. The latter is then dried, and reduced to powder, and subsequently purified by Avashing and drying in the manner above de- scribed (477). 479. Fibrin thus prepared is a pale-yellowish, horny- looking substance, hard, brittle, and, if all traces of fat have been removed, transparent. It is perfectly tasteless, and insoluble in Avater, alcohol, and ether ; if kept for a short time in water, hoAvever, it gradually softens, SAvells up, and reassumes the appearance it had previous to desicca- tion. When digested Avith acetic and most of the other acids, fibrin becomes gelatinous, and is in that state soluble in Avater. The acid solution, when treated Avith ferro- cyanide of potassium, gives a copious white precipitate, similar to that caused in albuminous solutions. Like albumen, and the other modifications of protein, it forms, when gently Avarmed with strong hydrochloric acid, a purple-colored solution. With nitric acid, also, fibrin behaves like the other protein compounds, forming the yelloAv xanthoproteic acid (469). 480. When examined under the microscope, coagulated fibrin appears to consist of a rude netAvork of amorphous threads, together with detached aggregations of irregular form, similar to albumen. 481. The average proportion of dry fibrin present in healthy blood, appears to be rather more than two parts in a thousand (573). SECTION V. Extractive Matters. 482. Of the real chemical nature of the substances in- cluded under the name of extractive matters, little is yet definitely known, though they have frequently engaged the attention of chemists. It is probable, however, that further researches will, ere long, throAV new light upon this at pre- sent obscure class of substances. They include all the un- defined, uncrystallizable organic matters which are soluble in Avater; or, in other words, the extractive matters of the blood may be said to include all the organic substances 158 HEALTHY BLOOD. contained in it, with the exception of the corpuscles, albu- men, fibrin, and fatty matters. 483. Extractive matters are usually divided into alcohol extractive and water extractive; the first including that portion which is soluble both in water and alcohol; and the latter, that which is soluble in wrater and insoluble in alcohol. They are of a brown or yellowish color, and are charac- terized by their solutions giATing brown precipitates with acetate of lead, but none with bichloride of mercury. A solution of the alcohol extractive is precipitated by an infu- sion of galls, which reagent causes little or no change in the water extractive. 484. Traces of urea are probably always present in the blood, and would be contained in the alcohol extractive. The method of detecting it Avill be described further on (598). The minute traces of uric acid which appear to be usually present even in healthy blood, would be contained in the water extractive ; the mode of detecting them is de- scribed in paragraph 604. 485. The amount of extractive matters present in healthy blood, seems to vary from one to three parts in a thousand. SECTION VI. Fatty Matters. 486. Our knowledge of the fatty matters contained in the blood is at present far from being complete. They are usually divided into oily fats and crystalline fats ; the first being soluble in cold alcohol, and the latter insoluble. The oily fats appear to consist chiefly of oleic (HO C H 0) and margaric (2HO,C68H6606) acids; the crystalline fatty matter is probably a mixture of serolin with traces of cho- lesterin (C36H320), together with one or more solid fats containing phosphorus. m 487. To obtain these fatty matters, a quantity of blood is evaporated to dryness on a water-bath, and the dry residue, after being reduced to powder, is digested in hot ether, successive portions of which must be added as Ions as anything appears to be dissolved by it. The ethereal solution is then evaporated to dryness on a water-bath, arid the residue, consisting of the mixed fats, treated with cold HEALTHY BLOOD. 159 alcohol, which will dissolve out the oily fats, and leave the crystalline matters undissolved. The first may be obtained by evaporating the alcoholic solution on a water-bath; and the undissolved crystalline fats may be dissolved in boiling alcohol, from Avhich they will almost entirely separate, as the liquid cools, in the form of small crystalline scales. 488. The quantity of fatty matters present in healthy blood appears to vary from 1*5 to 2*5 in 1000 parts (573). SECTION VII. Fixed Saline Matters. 4HD. The ash left after the incineration of the dry residue of evaporated blood appears to contain the following sub- stances—viz., the chlorides of sodium and potassium ; the phosphates of lime, magnesia, and soda; the sulphates of potash and soda; and oxide of iron derived from the haematin (455). If the ash has been obtained by the incine- ration of the serum, traces of alkaline and earthy carbo- nates will probably be rendered apparent by the efferves- cence caused by the addition of an acid; but if the ash has been obtained by the incineration of the entire blood, no trace of carbonates will be observable on the addition of the acid. The cause of this appears to be, that some of the fatty matters present in the clot contain traces of phos- phorus (486), Avhich during combustion, is converted into phosphoric acid (P05); and the phosphoric acid thus formed decomposes the small quantity of carbonates derived from the serum, converting them into phosphates. 490. The saline matters of the blood may be conve- niently divided into the alkaline salts, which readily dissolve in water, and the earthy salts, which require an acid for their solution. The alkaline portion of the ash consists of the chlorides of sodium and potassium; the sulphates of potash and soda ; and phosphate, with possibly traces of carbonate (489) of soda. The earthy or insoluble portion contains the phosphates of lime and magnesia; oxide of iron derived from the red coloring matter: and possibly a little earthy carbonate (489). The presence of the bases and acids contained in these several salts may be shown by the following experiments. 160 HEALTHY BLOOD. 491. Digest from twenty to thirty grains of the ash in warm Avater, in order to dissolve out the alkaline salts, and filter the solution from the insoluble portion. The aqueous solution thus obtained may be first tested, retaining the earthy residue for subsequent examination (499). 492. If the aqueous solution is at all dilute, it should first be concentrated by evaporation. To a little of the concen- trated solution, add a slight excess of tartaric acid (2IIO, C8^r4(?10), and agitate the mixture with a glass rod. A co- lorless crystalline precipitate of the bitartrate shows the presence of potash. 493. To another portion of the solution add a solution of bichloride of platinum (PtCl2), and alloAV the mixture to evaporate to dryness, either spontaneously or at a very gentle heat. Minute yellow granular crystals of the double chloride of platinum and potassium (KCl,PtCl2) will be found deposited, also showing the presence of potash. In addition to these will be seen long, yellow, needle-shaped crystals of the double chloride of platinum and sodium, proving the presence of soda, a few detached cubical crystals of chloride of sodium will also be deposited, Avhich may be proved to be such by their well-knoAvn taste. 494. The presence of soda may also be shown by adding to a little of the strong aqueous solution a few drops of an- timoniate of potash (KO,Sb05), which will gradually cause a colorless crystalline precipitate of antimoniate of soda (NaO,Sb05). 495. To another portion of the aqueous solution of the ash, add a solution of chloride of barium, or nitrate of ba- ryta, as long as it causes any precipitate. The sulphuric phosphoric, and (if any (489) ), carbonic acids, are thus throwndoAvn in combination with baryta. The mixture containing the precipitate thus produced, is now strongly acidified with hydrochloric or nitric acid, and Avarmed. If effervescence occurs on the addition of the acid, carbonic acid is probably present. The presence of sulphuric acid is shown by a portion of the precipitate (sulphate of baryta) proving insoluble in the acid. ; ♦ ^G'*f USr the, Sdd mixture formed in (495), and neu- tralize the filtered liquid with ammonia. The phosphate of baryta (2BaO,HO,P05), which had been dissoVJ bythe HEALTHY BLOOD. 161 acid, is reprecipitated, indicating the presence of phos- phoric acid (498). 497. Acidify another portion of the aqueous solution of the ash AA'ith nitric acid ; add a slight excess of nitrate of silver, and filter the liquid from the white precipitate occa- sioned by the silver salt. This precipitate may be proved to consist of chloride of silver (hydrochloric acid), by being readily soluble in ammonia, and insoluble in nitric acid. 498. Accurately neutralize the acid solution formed in (497), with dilute ammonia ; the pale yellow phosphate of silver (3AgO,P05) which had been held in solution by the excess of acid, will now be precipitated, shoAving the pre- sence of phosphoric acid (4-96). 499. The earthy portion of the ash, which proved in- soluble in water (491), may now be examined. It is to be dissolved in as small a quantity as possible of dilute hydro- chloric acid, a gentle heat being applied if necessary. If effervescence occurs on the addition of the acid, carbonic acid is present (489). 500. A little of the acid solution may now be nearly neutralized with dilute limmonia, which should not be added in sufficient quantity to cause any precipitate. The liquid is then tested with a drop or two of a solution of ferro- cyanide of potassium, which will cause, either at once, or in the course of a few minutes, a blue color, owing to the formation of the ferrocyanide of iron (Fe43FeCy3), show- ing the presence of iron. 501. The rest of the acid solution of the earthy portion of the ash may noAV be supersaturated with ammonia, which will throw down a Avhite gelatinous precipitate of earthy phosphates. A little of this precipitate may be examined under the microscope, when it will be found to consist chiefly of amorphous particles of phosphate of lime (8CaO,3P05), Avith a feAv crystals of the double phosphate of ammonia and magnesia (2Mg0,NH40,P05+12Aq). The precipitate thrown down by the ammonia may also be examined for lime, magnesia, and phosphoric acid, by redissolving it in acetic acid, and testing the solution in the manner described in paragraphs 47, 71, &c. 502. The quantity of alkaline salts usually present in 162 QUANTITATIVE ANALYSIS OF BLOOD. healthy blood, varies from about seAren to ten parts in 1000 ; and that of earthy salts from 0-5 to 1*5 in 1000 parts. CHAPTER II. QUANTITATIVE ANALYSIS OF BLOOD. 503. A complete quantatitive analysis of the blood, in- cluding the separation from each other, and estimation of all the ingredients, Avould be, even if our knoAAdedge and resources Avere much less limited than they are, in the highest degree complicated and difficult; while at present it may be said to be altogether impracticable. For most purposes, however, a comparatively incomplete analysis, embracing the determination of the more important ingre- dients, is all that is required; and in the majority of cases, a knowledge merely of the proportion of fibrin, the cor- puscles, and the solids contained in the serum, is what the medical practitioner chiefly requires. 504. I Avill first describe the mode of conducting such an analysis, by Avhich the amount of water, corpuscles, fibrin, and solids contained in the serum, may, with very little difficulty, be ascertained; and subsequently go through a somewhat more complete scheme, by which, in addition to the above substances, the more important constituents of the serum may also be individually estimated. See sections 3 & 4. 505. When the blood intended for analysis can be col- lected in the proper vessels as it Aoavs from the body, the process is somewhat simpler than when it has been allowed to coagulate; and the results are generally more accurate. As, however, this is frequently impracticable, I will also describe the method by which the analysis of coagulated blood may be effected. SECTION I. Quantitative Analysis of Uncoagulated Blood, includinq the estimation of the water, corpuscles, fibrin, and the solid matters contained in the serum. 506 Before proceeding to collect the blood as it flows from the body, for the purpose of analysis, the experimenter QUANTITATIVE ANALYSIS OF BLOOD. 163 should provide himself Avith three vessels, the exact Aveight of each of Avhich is to be carefully ascertained and noted. These vessels are— 1. A six- or eight-ounce bottle provided with a stopper; this bottle should be perfectly clean and dry, and of knoAvn weight. Eight or ten small strips of thin sheet lead, about half an inch square, the weight of which should also be knoAvn, are put into the bottle, which Avill then be ready to receive the blood (507). This bottle is used for effecting the separation of the fibrin. 2. A small platinum or Berlin porcelain capsule, capable of holding from half an ounce to an ounce of water. This is used for estimating the proportion of water in the blood (508). 3. A rather tall, upright beaker, or cylindrical glass, capable of holding about six ounces of Avater. 507. The blood may now be collected. About five or six ounces of the fluid are first poured into the bottle con- taining the fragments of lead, Avhich should then be tightly closed Avith the stopper, and kept gently agitated for about a quarter of an hour, in order to j^Ioav the Avhole of the fibrin to coagulate, and attach itself to the pieces of lead (477, 506). This portion of blood we will call A (510). 508. Tavo or three drachms of blood are collected in the capsule, which is then again accurately weighed, and the weight of the empty capsule, previously ascertained (506), deducted from the gross weight, in order to determine the exact quantity of blood contained in it. It may then be placed on a Avater bath, and evaporated to dryness. This portion Ave Avill call B (514). 509. The beaker or cylindrical glass is to be nearly filled Avith the frcshly-draAvn blood, covered with a glass plate, and set aside in a tolerably cool place for twenty- four hours ; at the end of Avhich time it Avill be found to be thoroughly coagulated, and separated into a firm clot and clear serum. This portion Ave will call C (516). 510. Treatment of the portion A.—When the blood has been gently shaken for about a quarter of an hour, imme- diately on being placed in the bottle (507), the fibrin -will be found to have separated, and collected round the frag- ments of lead which have been previously introduced. The 164 QUANTITATIVE ANALYSIS OF BLOOD. outside of the bottle is then cleaned with a wet cloth, and wiped dry. 511. The weight of the bottle, with its contents, is now taken, in order to ascertain the exact quantity of blood employed in the experiment, which is known by deducting from the gross weight that of the empty bottle and the lead, the difference being the Aveight of blood contained in it. 512. The stopper is noAV removed, and the contents of the bottle poured out into a small basin or saucer. The liquid portion is carefully poured off, and may be thrown aAvay; after Avhich the fibrin adhering to the lead is to be washed with a gentle stream of cold Avater, until it becomes colorless, in order to separate from it the whole of the cor- puscles and serum. During the Avashing, the spongy aggre- gations of fibrin may be gently pressed occasionally betAveen the fingers, care being taken that none of the fragments are lost. When clean, the fibrin is to be placed in a small evaporating dish, and dried on a chloride-of-calcium bath, at a temperature of 220° or 230°, until it ceases to lose weight. It is unimportant whether it is dried and weighed with the pieces of lead, or first separated from them, since the weight of the lead being known (506), may be deducted from the gross weight of the lead and fibrin, the difference being that of the fibrin. 513. The weight thus obtained represents the proportion of fibrin in the quantity of blood used in the experiment; the proportion in 1000 parts of blood may afterwards be ascertained by the following calculation : | Wt. of blood ) f AVt of fibrin ) .. . ( Quantity of fibrin in > i employed. i { obtained. J ■• 100° • | 1000 parts of blood. J 514. Treatment of the portion B.—The capsule contain- ing the portion B, after being accurately weighed (508), is allowed to remain on the water bath (or still better, on a chloride of calcium bath, heated to about 220° or 230°), until it ceases to lose weight on being weighed at intervals of half an hour or an hour, care being taken to wipe the outside clean and dry each time. When the weight becomes constant, it may be concluded that the whole of the water has been expelled. 515. From the weight thus obtained, that of the empty capsule is now to be deducted; the difference being the QUANTITATIVE ANALYSIS OF BLOOD. 165 weight of the entire solid matter contained in the quan- tity of blood operated on. The difference between the Aveight of this dry residue and that of the blood before evapo- ration, or in other Avords, the loss Avhich it has experienced during the evaporation, will then represent the amount of avater contained in the quantity of blood employed in the experiment. The proportion of solid matter and of water present in 1000 parts of the blood, may therefore be calcu- lated in the folloAving manner: For the Solid Matter. ( AVt. of A ( Wt. of ) ( Proportion of solid ] -{ blood \- : ] dry [ :: 1000 : < matter in 1000 \ [ evaporated. J ( residue. ) f parts of the blood. ) For the Water. I Wt. of 1 l Loss of AVt. ) { Proportion of water 1 ? blood \ : < during S :: 1000 : I in 1000 parts of > ( evaporated. ) ( evaporation. ) ( the blood. ) 516. Treatment of the portion C.—The third portion of blood which was collected in the beaker (50!)), is alloAvcd to stand for about tAventy-four hours, or until it separates into a firm clot and clear serum. Tavo or three drachms of the clear scrum are carefully poured off from the clot into a small platinum or porcelain capsule, similar to that before used (506), the Aveight of Avhich has been previously accu- rately noted. The capsule with the serum is now Aveighed, to ascertain the quantity of the latter employed in the experiment, and then evaporated to perfect dryness on a chloride of calcium bath, at a temperature of about 230°, until it ceases to lose Aveight. The loss of weight which it experiences during evaporation, represents the amount of water in the quantity of serum used; Avhile the weight of the dry residue shows the amount of solid matter contained in the same quantity of serum. 517. From the numbers noAv obtained, we are enabled to calculate the proportion of the solid matters of the serum in 1000 parts of blood, in the folloAving manner. Knowing, as Ave do, the quantity of water in 1000 parts of the blood (515); and assuming (as we safely may) that the water of the blood exists Avholly in the form of serum ; knoAving also the proportion of Avater and of solid matter contained 166 QUANTITATIVE ANALYSIS OF BLOOD. in the serum (516); we may, from the quantity of water in the blood, estimate the quantity of solids held in solution in the serum, thus: (Wt. of water 1 f Wt. of solid mat-1 (AVater in 1 f Solids of ] in the quan-1 . J ter in the qnan- I ! 1000 pts. I . J serum in ( tity of serum] '• j tity of serum [ ' • 1 of the j • ] 1000 pts. of [ employed, j [ employed. J { blood. J { the blood. J 518. We have noAV determined the proportion of water, fibrin, and solid matters of the serum, contained in the blood, and have only to ascertain the weight of the corpuscles, in order to complete the analysis. This is done by adding together the weights of the fibrin and the solids of the serum contained in 1000 parts of blood, and deducting the sum of them from the weight of the entire solid matter, which consists of fibrin, solids of the serum, and corpuscles; the difference therefore will represent the proportion of the latter in 1000 parts of the blood. 519. The several results now obtained may be recorded thus ; and the numbers, when added together, should amount to within a fraction of 1000. Water,........ Corpuscles, ....... Fibrin,........ Solid matters of serum, ..... 100000 SECTION II. Quantitative Analysis of Coagulated Blood, including the estima- tion of the water, corpuscles, fibrin, and the solid matters con- tained in the serum. 520. The portion of blood intended for analysis, which may consist of about ten fluid ounces, should be collected in a weighed or counterpoised glass beaker, or other cylin- drical vessel, and accurately weighed; or if it has been accidentally collected in any vessel of which the weight has not previously been determined, it may be Aveighed as before, *? i*i jTeight °f the containing vessel, ascertained after the blood has been removed, deducted from the gross weight • the difference being, of course, the weight of the blood em- ployed. The blood, after being collected, is to be set aside QUANTITATIVE ANALYSIS OF BLOOD. 167 in a tolerably cool place for about twenty-four hours, to allow it to coagulate ; the top of the glass being covered with a glass plate or small dish, to preserve it from dust and pre- vent evaporation. 521. About two or three fluid drachms of the clear serum are to be drawn off with a pipette, or carefully poured off, into a small weighed platinum or porcelain capsule; after being accurately weighed, it is to be evaporated, until it ceases to lose weight, on a chloride of calcium bath, kept at a temperature of about 220°. When dry, the weight is noted ; the loss during evaporation representing the amount of water in the quantity of serum operated on, and the weight of the dry residue being that of the solid matter contained in the same. The relative proportions of solid matter and water which form the serum, are thus ascer- tained. 522. While the evaporation of the serum (521) is going on, the examination of the rest of the coagulated blood may be proceeded with. The serum is first poured off from the clot with great care, avoiding the escape of any portion of the coagulum; the last portions of the liquid being removed by means of a fine-pointed pipette, or by introducing one end of a folded piece of bibulous paper, which will suck up the liquid until it is saturated, and may then be replaced by another. This serum, although it will probably not be wanted for any subsequent experiments, had better be for the present retained, in case of any accident happening to the portion already taken for evaporation (521). 523. The clot thus separated from the greater part of the serum, is now to be divided, by means of a sharp knife, into two portions of equal weight; the weight of both being accurately made to correspond by weighing, and adding or taking off small slices, as necessity may require. When this is done, each portion will contain one-half the fibrin and corpuscles of the quantity of blood operated on, toge- ther with a certain amount of serum. One of these equal portions of the clot we will call A, and the other B. 524. Treatment of the portion of clot A.—This is to be cut into thin shreds with a clean, sharp knife, carefully avoiding any loss of the fragments of the coagulum. The finely sliced clot is then tied up in a piece of fine muslin 168 QUANTITATIVE ANALYSIS OF BLOOD. or calico, and Avashed under a gentle stream of cold Avater, Avith the assistance of occasional pressure betAveen the fingers and thumb, until the Avhole of the serum and cor- puscles are remoAred from the interstices of the coagulum, and the fibrin is left quite clean and colorless. It is then taken out of the muslin, and dried on a chloride of calcium bath until it ceases to lose weight. The weight thus ob- tained represents the fibrin contained in half the clot, and when multiplied by two, gives the proportion of fibrin in the quantity of blood employed. 525. Treatment of the portion of clot B.—The weight of the portion B having been noted, it is to be evaporated to dryness on a chloride of calcium bath in a counterpoised or Aveighed capsule. The loss of weight which it experiences during evaporation, shows the quantity of water contained in half the clot, which, Avhen multiplied by tAvo, gives the amount of water present in the entire clot; Avhile the weight of the solid residue, also multiplied by two, shows the quantity of solid matter which the entire clot contains. 526. From the data thus obtained, we are enabled to calculate the proportion of the several constituents, in the following manner. Having ascertained the Aveight of the whole solid matter of the clot (525), which consists of fibrin, corpuscles, and solids contained in the portion of serum with Avhich the clot is saturated, we first calculate hoAv much of the weight is due to the solids of the serum. To do this, we assume that the Avhole of the water present in the clot is due to serum; then, knowing, from a previous experiment (521), the relative proportions of water and solid matter in the serum, and knowing also the quantity of water contained in the clot (525), Ave calculate the amount of solid matters in the clot, Avhich belong to the serum, as follows : AVt. of water "\ r Wt. of solid \ ( AVt. of \ ( AVt. of solid in quan- F 1 matter in I ] water ( | matters of tity of > : < quantity of V ;; J in the V • J serum, con- Berum ( ) serum I ) entire [ " \ tained in the evaporated. ) 1^ evaporated. J [^ clot. ) [^ entire clot. 527. The weight, thus calculated, of solid matters of serum present in the clot, is deducted from the weight of the entire solid matter contained in the clot (525), and the difference will represent the Aveight of the fibrin and cor- QUANTITATIVE ANALYSIS OF BLOOD. 169 puscles. Having, therefore, previously determined, by a separate experiment (524), the amount of fibrin, we have only to deduct that number, in order to obtain the propor- tion of corpuscles in the quantity of blood operated on. 528. Knowing now the amount of the fibrin and corpus- cles, we can, by deducting their combined weights from that of the entire blood, learn the quantity of serum which it contained, since the blood is wholly composed of fibrin, corpuscles, and serum. 529. From the weight of serum thus obtained, assuming that the whole of the water in the blood is due to the serum, we can calculate that of the water and solid matters OF the sbrum contained in the entire blood, in the following manner, since we have before determined, by experiment (521) their relative proportions. For the Water. { AVt. of serum ) f Loss of wt. 1 f Wt. of serum ~) (Proportion") which was 1 . J during I .. 1 in quantity I . J of water in [ evaporated f " J evapora- [ " ) of blood ( ' j quantity of ( to dryness. ) (. ration. J (_ used. J (_ blood used. J For the Solid Matters of the Serum. r Weight of -\ ( Weight of ~\ ( Weight of "\ r Wt. of solid "\ j serum which I j solid [ I serum in ( J matters of I J was evapo- s. ; J residue of \ •• J quantity S. ; J serum in v j rated to I j serum after ( \ of blood ( J quantity of I ^ dryness. J (^ evaporation. J (^ used. J ^_ blood used. J 530. We shall now, therefore, have ascertained the pro- portions of the four several constituents required, in the quantity of blood employed in the analysis, viz. : Water, ......... Corpuscles, ........ Fibrin,......... Solid matters contained in the serum, . . ------- which, when added together, should amount very nearly to the weight of the blood used. 531. In order to determine the proportion of the several constituents present in 1000 parts of the blood, the follow- ing calculation will in each case be necessary : 1000 Proportion of that constituent in 1000 parts of the blood. 170 QUANTITATIVE analysis of blood. SECTION III. Quantitative Analysis of Uncoagulated Blood, including the determination of the Water, Corpuscles, Albumen, Fibrin, Alcohol Extractive, Water Extractive, Oily Fats, Crystalline or Solid Fats, and Fixed Saline Matters. 532. The vessels required for this analysis are nearly the same as those already described in the shorter scheme of analysis (506)—viz.: 1. A six or eight-ounce stoppered bottle, the weight of Avhich is accurately known ; and in which are placed a few small strips of thin sheet lead, the weight of which also is knoAvn. 2. A weighed platinum capsule or crucible, capable of holding rather more than an ounce of liquid; or, in default of this, a thin Dresden porcelain crucible, of about the same capacity. And 3. A tall upright beaker or cylindrical glass, capable of holding about eight ounces of liquid. The weight of this need not be taken. 533. The three vessels being in readiness, the blood is first to be collected. About six ounces of the fluid are allowed to Aoav into the bottle, which should immediately be closed with the stopper, and gently shaken for a quarter of an hour or tAventy minutes, at the end of which time the fibrin will be found to have separated from the liquid, and attached itself round the fragments of lead. This portion of blood we will call A (536). 534. About an ounce of blood is collected in the weighed capsule or crucible, and, after being weighed for the pur- pose of ascertaining the exact quantity of blood employed, it is placed on a water bath or chloride-of-calcium bath, and allowed to evaporate. This portion we will call B (539). 535. From six to eight ounces of blood are allowed to flow into the beaker, and set aside to coagulate in a tolera- bly cool place for about twenty-four hours. This portion we will call C (541). 536. Treatment of the portion A.—As soon as the fibrin is supposed to have separated completely from the blood, and become attached to the pieces of lead, the outside of the bottle is to be Aviped clean and dry, and the whole is QUANTITATIVE ANALYSIS OF BLOOD. 171 weighed ; when the difference between the combined weights of the empty bottle and the lead, and that of the whole when filled, will represent the quantity of blood employed in the experiment. 537. The contents of the bottle are now to be emptied out into a small evaporating basin, and the fibrin is to be carefully separated from the fragments of lead, to which it adheres loosely. It is then Avashed, under a gentle stream of cold water, from the serum and corpuscles with which it is saturated, carefully avoiding the loss of any particles of the fibrin. 538. When quite clean and colorless, the fibrin is placed in a platinum or thin porcelain crucible of known weight, and dried on a chloride of calcium bath, at a temperature of about 220° or 230°, until it ceases to lose weight. When dry, the Aveight is noted. As the fibrin, in its present state, contains traces of earthy phosphates, which add slightly to its apparent Aveight, it may now be incinerated in the crucible, until the ash becomes Avhite or gray. The loss of .weight Avhich the dry fibrin experiences during incineration, represents the amount of pure fibrin in the quantity of blood that Avas contained in the bottle. The proportion present in 1000 parts of the blood may then be calculated as follows:— (Weight of) (Weight of) I Proportion of 1 I blood \ : ] fibrin \ :: 1000 : < fibrin in 1000 \ ( employed. S ( obtained. ) (pts. of blood. ) 539. Treatment of the portion B.—This portion of the blood, after being weighed, is alloAved to remain on a ehloridc-of-calcium bath, heated to about 220°, until it ceases to lose Aveight; when it may be concluded that the whole of the Avater has been expelled. When this is the case, the Aveight is noted; and the proportion of avater and solid matters of the blood, contained in 1000 parts of the fluid, may be calculated as folloivs: For the Water. i AVt. of blood 1 ( Loss of wt. ) ( < evaporated. \ : < during > : : 1000 : \ f to dryness. ) ( evaporation. ) ( ( Proportion of 1 water in 1000 ! pis. of blood. ] 172 QUANTITATIVE ANALYSIS OF BLOOD. For the Solid Matter. I Wt. of blood ) ( Weight of) ( Proportion of solid ) I evaporated > : < dry \ ; ; 1000 : < matter in 1000 S ( to dryness. ) ( residue. S ( pts. of blood. ) 540. The dry residue (539), after being weighed, is to be incinerated in the capsule or crucible, until the whole of the charcoal of the organic matter is burnt away, and the ash becomes of a pale red color. The weight of the ash thus obtained, shows the amount'of fixed saline matter in the quantity of blood evaporated; and from this, the' proportion contained in 1000 parts of the blood may be thus estimated: C Weight of A C Wt. of ash") ( Proportion of fixed ( I blood V : < after in- S- ; ; 1000 : < saline matter in (evaporated.) ( cineration. j ( 1000 pts. of blood. 541. Treatment of the portion C.—This portion of blood is allowed to stand for about twenty-four hours, in order that it may coagulate spontaneously, and divide itself into a firm clot and perfectly clear serum. 542. Two or three fluid drachms of the serum ^are first removed from the surface, and placed in a small platinum or porcelain capsule ; the exact quantity of serum taken, being ascertained by again Aveighing the capsule and its contents. It is then placed on a chloride of calcium bath, and Avhen perfectly dry, again weighed, in order to deter- mine the relative proportions of solid matter and water in the serum; the weight of the dry residue, and the amount of loss during evaporation, representing respectively the proportion of solids and of water, in the quantity of serum employed. 543. From the numbers thus obtained, Ave are able (as- suming that the whole of the water in the blood exists in the form of serum) to estimate the quantity of serum con- tained in 1000 parts of the blood, since Ave have before ascer- tained the amount of water in 1000 parts of blood (539), and also the relative proportion which the serum bears to the water contained in it (542), thus : Wt. of water "\ C Weight of in the quan- 1 1 serum tity of serum I . J which was that was f~ ' "\ evapo- evaporated 1 1 rated to to dryness. J ^. dryness. r Weight of "A r AVeight of I water I I serum J in 1000 I J in 1000 ^ parts | "A parts (^ blood. J (. blood. QUANTITATIVE ANALYSIS OF BLOOD. 173 544. Another portion of the clear serum, weighing exactly 500 grains, is noAv to be Aveighed out in a platinum or porcelain capsule, and evaporated to dryness on a water- bath. This Avill serve for the estimation of the albumen, oily and crystalline fats, and alcohol and water extractives. 545. The dry residue is to be carefully detached, by means of a knife, from the capsule, which should be placed ou a sheet of clean paper, in order to catch any fragments that may be projected over the sides of the capsule. The dry mass is then reduced to fine poAvder in a mortar, also placed on a sheet of paper, carefully avoiding the loss of any of the particles. The poAvder is then digested in suc- cessive small quantities of boiling ether, which may be poured off, as the insoluble matter readily subsides to the bottom of the capsule (547). 546. The ethereal solution thus obtained, containing the fatty matters, both oily and crystalline, is to be eA'aporated in a capsule of known Aveight, on a water-bath, until the whole of the ether is expelled. The residue is now weighed, by which the whole amount of fatty matters is ascertained. It is then treated with cold alcohol, which will dissolve out the oily fat. The weight of the residue left on evaporating the alcoholic solution, therefore, will represent the amount of oily fat in 500 grains of serum ; and the difference between this and the Aveight of the Avhole fatty matter sIioavs the quantity of solid or crystalline fatty matter in the same serum. The proportion of each of these, Avhich is contained in 1000 parts of blood, may then be calculated as folloAvs : For the Oily Fat. f AVt. of oily I ( Wt. of serum ) ( Proportion of oily "1 600 : \ fat in 500 > : : -j in 1000 parts > : -j fat in 1000 parts [■ I. grs. of serum. J I of blood. j (. of blood. ) For the Crystalline Fatty Matter. ( Wt. of crystal-) f AVt. of serum ) ( Proportion of crys-1 500 : -j line fat iu 500 \ :: -j in 1000 parts > .- J "talline fat in 1000 >■ I. grs. of serum. J (.of blood. J (. parts of blood. J 547. The residue which proved insoluble in the ether (545), is noiv to be warmed, in order to expel any traces of ether that still may be present, and then treated with boil- ing Avater, Avhich will coagulate the albumen, thus render- fa 15* 174 quantitative analysis of blood. ing it insoluble; while the extractive matters are dissolved out (549). The mixture is then filtered, and the insolu- ble residue of albumen washed on the filter with hot Avater, until a drop of the filtered liquid causes no precipitate, or merely a very slight opalescence, when tested with a solu- tion of nitrate of silver. 548. The albumen, thus freed from extractive and solu- ble saline matters, is to be dried and weighed ; but as some traces of inorganic matter are ahvays associated with the albumen, the dry mass is to be incinerated, and the weight of the ash deducted from it; when the difference will represent the amount of pure albumen in 500 grains of serum. The proportion in 1000 parts of blood may then be calculated thus: {Wt. ofalbu- ) f Wt. of serum 1 ( Proportion of albu-1 men in 500 Y : : -j in 1000 parts Y : -j men in 1000 parts Y grs. of serum. J (.of blood. J (.of blood. ) 549. The aqueous solution filtered from the albumen (547), containing the extractive matters and soluble salts, is now to be evaporated to dryness in a capsule of known weight, on a water-bath, and Aveighed. The dry residue is then treated with alcohol, which should be poured off and renewed as long as anything continues to be dissolved by it. The alcoholic solution is evaporated to dryness on a water-bath, and Aveighed; it is then incinerated, and the weight of the ash is deducted from that of the dry mass previous to incineration. The number thus obtained re- presents the amount of alcohol extractive in 500 grains of serum, which may be reduced to the proportion in 1000 parts of blood, as follows: ( Wt. of alcohol "I ( AVt. of serum 1 ( Proportion of alcohol 1 500 : S extract in 500 Y : : ■< in 1000 parts Y : -j extract in 1000 parts f I grs. of serum. J t of blood. ) t of blood. J 550. The portion of the dry residue which proved in- soluble in alcohol (549) is now to be dried, weighed, and ignited ; the Aveight of the ash being deducted from that of the dry mass previous to ignition. This will give the weight of the avater extractive in 500 grains of serum; from which the quantity in 1000 parts of blood may be estimated as in the former cases: f AVt. of water A f Wt. of serum ) ( Proportion of water ) 500 : < extract in 500 Y :: < in 1000 parts Y : ■{ extract in 1000 parts Y I grs. of serum. ) ( of blood. ) ( of blood. J quantitative analysis of blood. 175 551. We shall now have estimated the proportion of water, and of all the solid constituents, with the exception of the corpuscles. The proportion of these is known by deducting the sum of the seA'eral solid matters, the weights of which are already determined (including everything but the corpuscles), from the weight of the Avhole solid matter contained in 1000 parts of blood (539), the difference repre- senting the proportion of corpuscles present in 1000 parts of the fluid. 552. The results of the analysis may then be recorded as follows, and should, when added together, amount to a fraction less than 1000. Water,......... Corpuscles, ........ Albumen,......... Fibrin,......... Alcohol extractive, ....... Water extractive, ....... Oily fals,......... Crystalline or solid fats, ...... Fixed saline matter, ...... SECTION IV. Quantitative Analysis of Coagulated Blood, including the esti- mation of the water, corpuscles, albumen, fibrin, alcohol extrac- tive, water extractive, oily fats, crystalline or solid fats, and fixed saline matters. 553. About ten or twelve ounces of blood having been collected in a beaker, or other rather tall vessel of known Aveight, it is to be covered over to prevent evaporation, and set aside in a cool place for about tAventy-four hours, Avhen it will be found to have separated into a firm clot and clear serum. The Aveight of the Avhole blood is to be accurately determined either before or after coagulation. Three or four fluid drachms of the clear serum are first drawn off with a pipette, Aveighed in a platinum or porcelain crucible of knoAvn Aveight, evaporated to dryness on a chloride of calcium bath, and the Aveight of the dry residue ascertained. The loss of Aveight during evaporation representing the 176 QUANTITATIVE ANALYSIS OF BLOOD. water, we thus determine the relative proportions of solid MATTER AND WATER IN THE SERUM. 554. The dry residue of the serum (553) is now to be incinerated, until the ash becomes Avhite or gray ; and the latter is then weighed. The proportion of fixed saline matter of the serum is thus ascertained. 555. The greater part of the remaining clear serum is now to be carefully poured off from the coagulum, and re- tained for further examination (565). The last portions of the liquid are to be remoAred by means of a fine pipette, or by sucking it up with little rolls of bibulous paper (522), carefully avoiding the removal of any portions of the clot. _ 556. The coagulum, thus separated as completely as pos- sible from the serum, is now to be divided into two portions of exactly equal Aveight (523), each of which will then con- tain one-half of the fibrin and corpuscles present in the quantity of blood operated on, together with a certain amount of serum. These two equal portions of clot we will distinguish as A and B. / 557. Treatment of the portion of clot A.—This portion ot the clot is to be cut with a sharp knife into fine slices carefully avoiding any loss. These are then tied up in a piece of fine muslin, and washed, until they become quite colorless, Avhen it may be concluded that the whole of the corpuscles and serum have been washed out. The fibrin is Tut >40ri a1Chl0^de?f caTIcium ^th at a temperature of about 2.0 and weighed. It still, however, contains traces W X J ii' • ^ qTtity °f Which is kn^n by incinerat ing the dry fibrin, and deducting from it the weight of the ash. The loss of weight during incineration represents thl quantity of fibrin contained in" one-half the clot andtbt ttir >phe/Jfy V™' ^VeS the ProportionTiS^S tiie_ quantity of blood employed. 1W in 008 Treatment of the portion of clot B — This half „f tity of WATER CONTAINED r»™r »L ' g he ^^^ weigM„f *. dry .e^r™--^ the QUANTITATIVE ANALYSIS OF BLOOD. 177 sents the amount of solid matter present in the entire CLOT. The dry residue of B is to be retained for subsequent in- cineration (563). 559. Having thus determined the weight of the Avhole solid matter of the clot, Avhich consists of fibrin and cor- puscles, together Avith the solids contained in the portion of serum with Avhich the clot is saturated, we now have to calculate hovv much of the Aveight is due to the solids of the serum. Assuming that the whole of the water present in the clot is due to the serum, and knowing the relative proportions of Avater and solid matter in the serum (553); knowing also the quantity of Avater present in the entire clot (558); the amount of solid matters in the clot which belong to the serum may be calculated in the following manner: Wt. of water ) ( Wt. of solid ) ( Wt. of A ( AVt. of solid mat- J in quantity f 1 matter in f _ 1 water f # 1 ters of serum, f of serum ( '• \ quantity of £ ■ • \ in entire t '• } contained in the ( evaporated. ) ' serum evap. * ' clot. ) ' entire clot. * 560. The weight of solid matters of the serum thus found to be present in the clot, is to be deducted from the Aveight of the entire solid matter of the clot (558), Avhen the difference will represent the weight of the fibrin and cor- puscles ; the weight of the fibrin, hoAvever, having been already ascertained by a separate experiment (557), we have merely to deduct that amount, in order to determine the proportion of corpuscles in the quantity of blood employed in the analysis. 561. Now since the blood may be said to consist wholly of fibrin, corpuscles, and serum; and knowing, as we do (557, 560), the weight of the fibrin and the corpuscles; we can, by deducting the combined Aveights of those two sub- stances from the weight of the entire blood, learn the pro- portion of serum in the quantity of blood operated upon. 562. But Ave have before determined the relative propor- tions of solid matter and water in the serum (553); so that, assuming that the whole water of the'blood is due to the serum, avc can, from the quantity of serum obtained in paragraph 561, estimate the proportion of water in the blood, thus: 178 QUANTITATIVE ANALYSIS OF BLOOD. (Wt. of serum A f Loss of wt. A C Wt. of serum A f Proportion A which was { _ J during eva- [ J in quantity f ! of water in [ evaporated j • j poration j • • ] of blood j •* 1 quantity of f to dryness. J (. (water). ) (. used. J I blood used. J 563. The dry residue of the portion of the clot B (558) is noAv to be incinerated. The Aveight of the ash thus ob- tained, multiplied by two, will give the amount of the inor- ganic salts contained in the clot. A certain portion of this wTeight, hoAvever, is due to the salts of the serum Avhich Avas contained in the clot, the amount of Avhich may be learned by the folloiving calculation, since we have before deter- mined the relative proportions of solid matter and inorganic ash in the serum (553, 554). ( Wt. of solid mat J ter in quantity J of serum evapo J rated to (^ dryness. By deducting this number from the weight of the ash of the whole clot, avc ascertain the amount of inorganic saline matter derived from the fibrin and corpuscles. 564. In order to determine the whole amount of fixed salts in the blood, we must now reckon how much the whole of the serum contains. This is done as follows : i ess j ■ te-j:: HroH : I «SS-1 By adding together the ash of the serum thus obtained, and that derived from the fibrin and corpuscles (563) we ascertain the proportion of fixed saline matter in the quantity of blood employed in the analysis. 565. Estimation of the albumen, extractives, and fatty matters.-Five hundred grains of the clear serum (555) are to be weighed outm a platinum or porcelain evaporating baBm, and evaporated to dryness on a water-bath. Thf basin is then placed on a clean sheet of paper, and the drv residue carefully detached from it, and Educed to £ powder in a mortar, taking care that none of the small fragments are lost. The pulverized residue is then treated with successive small portions of boiling ether untd all thp soluble matter is removed (545) g ' the drynes's^a ct^t^11 ^ "7 t0 be eVaP°™ted to dryness in a capsule of known weight on a water"hath, and QUANTITATIVE ANALYSIS OF BLOOD. 179 the residue of fatty matter weighed. This is then di- gested with cold alcohol, in order to dissolve out the oily fat, Avhich will be left as a residue after evaporating the alcoholic solution to dryness. The weight of this oily fat is then taken ; and the difference between this weight and that of the whole fatty matter left on evaporating the ethereal solution, will represent the quantity of crystalline or solid fat contained in five hundred grains of serum. 567. The proportions of these fats present in the whole quantity of blood employed in the analysis, are calculated as follows : For the Oily Fat. ( Wt. of oily ] ( AVt. of serum in ) ( Proportion of oily 1 500 : -j fat in 500 grs. Y : i quantity of blood Y : < fat in quantity Y I of serum ) (. used (561). J (of blood used. J For the Crystalline Fat. ( Wt. of crystal-1 ( Wt. of serum in ] f Propor. of crystal-1 500 : -j line fat in 500 Y '• '• ] quantity of blood Y : -j line fat in quan- Y (. grs. of serum. ) I used (561). ) I tity of blood used. J 568. The portion of the residue which proved insoluble in ether (565) is now warmed, to expel the still adhering ether, and then digested in boiling water, Avhich Avill dis- solve out the extractive matters, leaving the coagulated albumen undissolved. The latter is separated from the solution by filtration, and washed with warm Avater until the washings cause merely a slight opalescence when tested with nitrate of silver. The albumen is dried, Aveighed, and the dried mass then incinerated, in order to determine the amount of inorganic ash with which it is associated. The ash is weighed, and its wTeight deducted from that of the dry mass previous to incineration. The difference between the tAvo Aveighings represents the quantity of albumen in 500 o-rains of serum. The proportion of albumen contained in the Avhole quantity of blood may then be estimated as follows : !Wt of albu- A C AVeightof A f Proportion of albu-1 men in 500 I . . J serum in [ J men in quantity I grains of • • j quantity of f ■ 1 of blood f serum. J v- blood used. J I used. J 569. The solution filtered from the albumen, and contain- ing the extractive matters and soluble salts, is evaporated to dryness in a capsule of knoAvn weight, on a water-bath, 180 quantitative analysis of blood. and weighed. The weight of the eA-aporated residue having been noted, it is exhausted with alcohol, and the alcoholic extract is evaporated to dryness on a Avater-bath, and Aveighed; it is then incinerated, and the weight of the ash is deducted from that of the dry mass previous to incinera- tion. The weight thus obtained represents the quantity of alcohol extractive in five hundred grains of serum ; which may be reduced to the proportion present in the whole quantity of blood used, in the following manner: Wt. of alco- hol extract. in 500 grs. of serum. {Weight of serum in quantity of blood used. Proportion of alcohol extractive in quantity of blood used. 570. The portion of the residue which the alcohol failed to dissolve (569), is now to be dried, weighed, and inci- nerated ; the weight of the ash being then deducted from that of the dry mass previous to incineration. This will give the weight of avater extractive contained in five hundred grains of serum; from which the proportion pre- sent in the whole quantity of blood used, may be estimated as before: {Wt. of water A extractive in 500 grains of f serum. I I Weight of serum in quantity of blood used. {Proportion of water" extractive in quantity of blood used. 571 The results of the analysis may then be summed up as follows; and if the experiments have been conducted with care the numbers will, when added together, coincide th^arXsfs ^^ quantit^ of bIood employed in Water, Corpuscles, Albumen, Fibrin, . Alcohol extractive, Water extractive, Oily fats, Crystalline or solid fats, Fixed saline matters, lowing calculation must iZJTelte^' ^ **' quantitative analysis of blood. 181 SY}' °I) i aaa ( wt- of each 1 ( < blood \ : 1000 :: •> constituent £ : 1' i HSe'1- > ( obtained. S ( Proportion of that con- stituent in 1000 parts of blood. The several quantities thus obtained should, Avhen added together, amount to a fraction less than one thousand. section v. Average Composition of Healthy Blood. 573. The following analyses will serve to show the usual composition of healthy blood. Analysis I. Healthy Venous Blood 130 Clot, 870 Serum, (Albuminous matter, (Dumas.) {Fibrin, Globules, JHfBmatin, Water, Albumen, . Oxygen, . Nitrogen, . Carbonic acid, Extractive matter, Phosphorized fat, . Cholesterin, . Serolin, Oleic and margaric acids, Chlorides of sodium and potassium, Muriate of ammonia, Carbonates of soda, lime, and magnesia, Phosphates of soda, lime, and magnesia, Sulphate of potash, . . . . Lactate of soda, . . . . . Salts of the fatty acids, . w Yellow coloring matter, 3 2 125 790 70 10 1000 1000 Analysis II. (Simon.) Water,..........795-278 Fibrin,..........2-104 Fat,..........2-346 Albumen,.........76-600 Globulin,.........103-022 Haematin,.........6-209 Extractive matter and salts,.....12-012 16 182 quantitative analysis of blood. Analyses III d- IV. (Becquerel and Rodier.) Showing the mean Composition of Male and Female Blood. Density of defibrinated blood, Density of serum, Water, Fibrin, Fatty matters, Serolin, Phosphorized fat, . Cholesterin, . Saponified fat, Albumen, Blood-corpuscles, . Extractive matters and salts, Chloride of sodium, . Other soluble salts, . Earthy phosphates, Iron, Male. Female. 1060-00 1057-50 1028-00 1027-40 779-00 791-10 2-20 2-20 1-60 1-62 0-02 0-02 0-49 0-46 0-09 0-09 1-00 1-04 69-40 70-50 141-10 127-20 6-80 7-40 3.10 3-90 2.50 2-90 0-33 0-35 0-57 0-54 Analysis V. (Lecanu.) Water, Solid residue, Fibrin, Organic residue of serum, Inorganic ditto, . Blood corpuscles, 790 210 3 72 8 127 Analysis VI. (Enderlin.) Showing the Composition of the Ash of Human Blood } Tribasic phosphate of soda (3NaOP05), . Chloride of sodium, . Chloride of potassium, Sulphate of potash, . Phosphate of lime, . Phosphate of magnesia, . Peroxide of iron and phos- . phate of iron, 22-100 54-769 4-416 2-461 3-636 0-769 10-770 83-746 | Sol"ble ( salts. 15-17 5 | Insoluble ( salts. 98-921 morbid blood. 183 CHAPTER III. morbid blood. 571*. The chemistry of the blood in its pathological con- ditions has, until within the last feAv years, occupied very little attention from the chemist or physician; the conse- quence of Avhich has been, that much ignorance has always prevailed, and it is to be feared still prevails among the great mass of the profession, respecting this important and interesting subject of inquiry. It is not unreasonable to anticipate that the fresh knowledge which we are now almost daily acquiring in this and other kindred branches of physiological and pathological chemistry, will gradually lead to highly important and beneficial practical results, in the more enlightened treatment of disease, and the more ready mitigation of suffering. 575. The variations which are found to occur in the chemical composition of morbid blood may be divided into two classes: 1st. Those in Avhich, so far as we are aware, no abnormal matter, not contained in healthy blood, is present; but in Avhich one or more of the normal constituents of healthy blood exist in a greater or less proportion than in the healthy fluid. 2d. Those in Avhich Ave can detect the presence of one or more abnormal matters Avhich are not found in healthy blood. 576. To the first of these classes belong those cases in which we find an excess or deficiency of Avater, corpuscles, albumen, fibrin, fatty matters, cholesterin, urea, uric acid, or inorganic salts ; and to the second, those in which either sugar, biliary matter, pus, entozoa, or other abnormal matter, can be detected. I will briefly notice each of these morbid conditions of the blood, together with the mode of examination, Avhether chemical or microscopic, which will be found most readily applicable to each. 184 MORBID blood. Class I.—Morbid Blood in ivhich no abnormal matter is present. SECTION I. Blood containing an Excess or Deficiency of Water. 577. The proportion of water even in healthy.blood appears to vary considerably, so that it is difficult to say what may be considered as the normal amount. The usual average, however, contained in human blood, seems to be from 790 to 800 in 1000 parts. 578. In some forms of disease, as, for example, anaemia and chlorosis, the proportion of water is usually much greater, and has been known to amount to upwards of 900 parts in 1000. In certain other pathological conditions, on the contrary, the blood is found to contain considerably less water than is present in the healthy fluid; in cholera, for instance, where the blood is so rich in solid matter as almost to resemble jelly in appearance, it has been knoAvn to contain not more than 480 parts of water in WOO. 579. The proportion of water present in any specimen of blood may readily be ascertained, by evaporating a known weight of the fluid in a weighed or counterpoised capsule, on a chloride of calcium bath, heated to about 220° or 230° until it ceases to lose weight. The loss of weight during the evaporation will then represent the proportion of water in the quantity of blood employed, which may be reduced to 1000 parts, as folloivs: f Weight of A ( , , _ \ blood Y : \ Loss of weight / ( Proportion of i I. evaporated. ) j during evaporation. 1 : : j water in 1000 J > I parts of blood. ) SECTION II. Blood containing an Excess or Defieiency of Corpuscles. hilt!!; L^ ^f^ P^ortion of corpuscles contained in 3 Tan,W00d apPears t0 be from 120 to 130 part* n 1000. In disease, especially in some forms of fever it other affections Ion. Ln ' i! ' m an*mia' and certai* poorness of Moo ffc "• bemg atten^ed with great poorness ot blood, the proportion of corpuscles frequently MORBID BLOOD. 185 does not amount to more than 60 or 70, and has been known to be as low as 21 in 1000 parts. 581. The direct determination of the weight of the cor- puscles is a matter of considerable difficulty, so that they are generally estimated by deducting the combined Aveights of the water, fibrin, and solid matters of the serum, which are easily determined experimentally, from that of the entire blood, in the manner described in paragraphs 518, 527, &c. 582. According to Figuier, their weight, may be deter- mined Avith considerable accuracy by mixing the blood, previously weighed and defibrinated by agitation with frag- ments of lead (507), with about twice its bulk of a strong solution of sulphate of soda (specific gravity 1*13), filtering through a filter of knoAvn weight,1 and Avashing the corpus- cles on the filter Avith a little more of the saline solution (456). When most of the liquid has drained through, the filter Avith its contents is dipped in boiling water, and allowed to remain in it some little time, in order to dissolve out the salt; while the organic matter of the corpuscles is coagulated by the heat, and thus rendered insoluble. The filter, with the corpuscles, is then dried at 212°, Aveighed, and the Aveight of the dry filter, previously determined, being deducted, the difference Avill represent the weight of the corpuscles contained in the quantity of blood operated on. 583. The microscopic appearance of the corpuscles is also not unfrequently found to vary under the influence of disease, the modifications of form occurring occasionally in the living body, but more frequently after death. Most of these changes are due to the phenomena of endosmosis or exosmosis already referred to (456). Thus they are sometimes met Avith having a more or less globular form, OAving to the entrance of fluid less dense than the serum of healthy blood ; at other times they are found to have a Avrinkled or indented outline, similar to that which the healthy corpuscle assumes Avhen placed in contact Avith strong saline solutions of high specific gravity. (See fig. 61, page 151.) 1 Sec Introduction to Practical Chemistry, second edition, p. 191. 16* 186 MORBID BLOOD. 584. In examining the blood-corpuscles under the micro- scope, with a view to detecting any abnormal appearance as a consequence of disease, it must be borne in mind that these and other analogous changes in the form of the cor- puscle, are artificially induced by the action of water or other liquids with which they may have been allowed to come in contact; such contact should therefore be carefully avoided. The wrinkled appearance is sometimes caused also by the concentration of the serous fluid, owing to spontaneous evaporation (456). SECTION III. Blood containing an Excess or Deficiency of Albumen. 585. The average proportion of albumen in healthy blood appears to lie between 70 and 75 parts in 1000; Avhile in disease it is occasionally (as in cholera) as high as 131, and (as m Bright's disease) as low as 55 parts in 1000. 586. The amount of albumen in any specimen of blood may be ascertained in the manner described in paragraphs 547, 568 ; or a weighed portion of serum may be carefully neutralized with dilute hydrochloric acid, diluted with an equal bulk of water, and boiled for about a quarter of an hour. _ The coagulum of albumen is then separated by nitration ; washed with a little boiling ether, in order to remove the fat; dried at 212°, and weighed before and after incineration; the difference between the two weighings (548) '"^ °f albUmen ln the qUantit? 0f serui* us^ ent^f thplS^^r8'™^011 °f the 0ther constit*- ents ot the blood may, if necessary, be conducted as in thp case of healthy blood (503, &c.) conauctecl as m the SECTION IV. Blood containing an Excess or Deficiency of Fibrin found to vary from a mere trace, to upwards of ten parts iS o«9. The peculiar appearance frequently to be seen after MORBID BLOOD. 187 coagulation, in blood taken from the body during certain pathological conditions, long known as the huffy coat, is caused by the upper portion of the clot being composed almost entirely of fibrin, or of some modification of protein closely allied to it, unmixed with the red corpuscles. This may be owing either to the blood-corpuscles subsiding in the liquid more rapidly than in ordinary blood, or to the fibrin coagulating more sloAvly; in either case the upper portion of the coagulated fibrin would be more or less free from the corpuscles to Avhich the red color of the ordinary clot is due. The blood in which the buffy coat is found to occur is in most cases, rather rich in fibrin, and it was formerly regarded as a sure sign of inflammation; an opinion Avhich has since been proved to be altogether erro- neous (454). • 590. The proportion of fibrin may already be determined either in coagulated or freshly drawn blood, in the manner already described. For freshly drawn blood, see paragraph 510, &c, and for coagulated blood, see paragraph 524, &c. The quantitative estimation of the other ingredients may also, if necessary, be conducted in the same manner as in healthy blood (503, &c.) SECTION V. Blood containing an Excess of Fatty Matter. 591. The average amount of fat in healthy blood appears to be something more than two parts in a thousand. The Avhole of the oily fat probably exists in combination with potash or soda, forming a kind of soap ; so that in the healthy fluid no oil-globules can be detected. 592. In certain pathological con- Fig 63 ditions, wTe occasionally meet Avith , _——----------— blood, containing a considerable : -J""® I o©@ *9®° quantity of free fat, which is held r^© © ©'•••R)V> in suspension, in the form of minute pi° ® • '^^2 9 ^ globules, in the serum, giving that j l\f %%\A ^©%• fluid a more or less opaque or milky (g^ °0 @*®..g aQ appearance. In this form of blood, | « . ^ go© j®),*°\g)' which, from its peculiar appearance, - FatinBiood. has been called milky blood, may be 188 MORBID BLOOD. seen, with the help of the microscope, innumerable fat-glo- bules, Avhich may be readily distinguished by their bright centres, and black well-defined outlines (Fig. 63). They may be separated by agitating the blood with a little ether, which Avill readily dissolve them. 593. The amount of fat in any specimen of blood may be determined by evaporating to dryness a knoAvn weight of the fluid, pounding the dry residue, and boiling it with successive small quantities of ether. The ethereal solution of the fat thus obtained is evaporated to dryness in a counterpoised capsule, and Aveighed; its weight represent- ing the proportion of fat in the quantity of blood employed. 594. The quantitative determination of the other con- stituents of the blood may, if required, be effected in the same manner as the healthy fluid (503, &c.) SECTION VI. Blood containing an Excess of Cholesterin: 595.^ Minute traces of cholesterin appear to be always present in healthy blood, though some observers have failed in their endeavors to detect it. The amount, however, in certain forms of disease not unfrequently rises as high as 0-15 to 0-20 in 1000 parts ; and in one case of so-called milky blood, Lecanu found not less than 1-08 in 1000. 596. When an excess of cholesterin is suspected to be present in any specimen of blood, it may be separated and estimated with tolerably accuracy in the following manner. Fig. 6i. A known weight of the blood is evaporated to dryness on a Avater-bath, and the dry residue, after being reduced to fine poAvder in a mortar, is digested for a few hours in ether, the solvent action being assisted by occasional boiling. In this way the cholesterin. cholesterin, together with j- i -i tne other fatty matters is issolved, and may be obtained by evaporative etherea solution on a water-bath. The residue is then deprived of 7999� MORBID BLOOD. 189 the oily portion of the fat, by digestion with cold alcohol, which leaves undissolved the cholesterin, with the other solid fatty matters; the crystalline scales of cholesterin (Fig. 64), which are easily distinguishable from the rest, may then be, for the most part, mechanically separated with the point of a knife. Their weight may then, after drying, be ascertained if necessary. 597. The quantitative estimation of the other constitu- ents may be conducted as in the case of healthy blood (503, &c.) SECTION VII. Blood containing an Excess of Urea: 598. Minute traces of urea are probably always present in healthy blood (484), though the amount is so small as to be incapable of determination, unless considerable quanti- ties of blood are used. In some forms of disease, however, especially in Bright's disease, cholera, and certain other pathological conditions, in Avhich the functions of the uri- nary organs are to any serious extent interfered with, the amount of urea is found to increase considerably, and may frequently be met with in a sufficiently large quantity to be weighed. 599. The detection and estimation of urea in the blood may be conducted in the following manner. A known weight of serum is first evaporated to dryness on a water- bath, at a very gentle heat, a precaution necessary to be observed, since a temperature of 212°, long continued, such as is required in this analysis, would probably cause the decomposition of some portion of the urea. The dry residue is reduced to fine poAvder in a mortar, and treated with distilled Avater, heated to about 200°, the quantity of which may be about double the volume of the serum em- ployed in the experiment. The mixture is allowed to digest for about half an hour at 200°, after which it may be filtered from the insoluble residue of albumen, which latter must be washed Avhile on the filter with a little more warm water. The filtered aqueous solution is now evaporated to dryness, and the residue digested with a little absolute alcohol, at a very gentle heat, which may be continued for 190 MORBID BLOOD. about half an hour ; a little fresh alcohol being added occa- sionally, to replace that lost by evaporation. The mixture is then filtered; the clear alcoholic solution is evaporated to dryness, and the residue treated Avith a little lukewarm distilled water, which will then contain merely the urea, together with a small quantity of extractive matter. 600. The aqueous solution thus obtained is evaporated at a very gentle heat, to the consistence of a syrup, and then mixed with a few drops of pure and colorless nitric acid (16, 182), the mixture being kept cool by immersing the glass containing it in a little cold water, or, still better, in a freezing mixture composed of equal weights of crys- tallized nitrate of ammonia and water. If urea is present, delicate crystalline plates of nitrate of urea (C2H4N202, HO,N05), Avill gradually appear (Fig. 2, page 29), which, if in sufficient quantity, may be dried by gentle pressure betAveen folds of filtering paper, and weighed. From the weight thus obtained, that of the urea in the quantity of serum employed may be calculated as follows: ( Atomicwt. ) ("Atomic ) f W4. „<•„;....„..„ 1 f Wt. ofureain 1 \ of nitrate. [ \ wt. of [ \ WtnV°tfinlt^te [ \ quantity of [ I of urea. ) (. urea. ) (. 0Dtamea- J ( serum employed. J 123 : 60 601. If no appearance of crystallization can be detected with the naked eye, a drop of the acid liquid, cooled by means of a freezing mixture, is to be examined under the microscope, by which means very small traces of urea may be detected (181). 602. The quantitative determination of the other con- stituents may be effected Avith a fresh portion of the blood, in the same manner as in the healthy fluid (503, &c.) SECTION VIII. Blood containing an Excess or Deficiency of Inorganic Saline Matter. _ 603. The average proportion of inorganic saline matter in healthy blood, appears to be about seven parts in 1000. In scurvy, and some other pathological conditions, their amount has been found to increase, and has been knoAvn MORBID BLOOD. 191 to amount to as much as eleven parts in 1000. In some other diseases, on the contrary, the amount falls below the healthy average. The proportion of fixed saline matter in any specimen of morbid blood, may be determined as in the case of the healthy fluid—viz., by evaporating to dryness a known weight, and incinerating the residue until the ash becomes nearly colorless. The weight of the ash thus obtained represents the amount of salts in the quantity of blood employed. 604. The presence of uric acid (urate of soda) in the blood of gouty patients, may be shoAvn by evaporating a little of the fluid to dryness on a Avater-bath, and, after washing the dry residue with alcohol, adding a slight excess of dilute hydrochloric or acetic acid to a strong aqueous solution of the extract which proved insoluble in the alco- hol. After standing a day or two, minute crystals of uric acid, similar to those formed in the urine, are gradually deposited, and may be identified under the microscope (186, 194), or by their behavior Avhen treated Avith nitric acid and ammonia (23). Even in healthy blood, minute traces of uric acid may generally be detected. Class II.—Morbid Blood containing some Abnormal Ingredient. SECTION IX. Blood containing Sugar (C12Hu01A). 605. The blood of patients suffering from diabetes, ap- pears most commonly to contain a very sensible amount of suo-ar. This may usually be detected in the following manner: 606. The portion of serum intended for examination is first evaporated to dryness, either in vacuo over sulphuric acid,1 or at a very gentle heat on a water-bath. The dry residue is then reduced to tolerably fine powder, and treated with a small quantity of boiling water, which will have the effect of coagulating the albumen, and dissolving 1 Sae Introduction to Practical Chemistry, second edition, p. 194. 192 MORBID BLOOD. out the sugar, together with the extractiAre matters and soluble salts. The mixture is then filtered, and the clear liquid examined for sugar, by means of Trommer's test, which may be thus applied : 607. The liquid is treated with a drop or two of a solution of sulphate of copper, and then supersaturated with potash (123), the excess of which will probably, if sugar is present, redissolve the blue precipitate of hydrated oxide of copper at first thrown down. The mixture may now be gently boiled for a few minutes, when, if sugar is present, an orange-brown or ochre-colored precipitate of suboxide of copper will be thrown down ; while, if no sugar is contained in the mixture, the precipitate will be nearly black (124). 608. It is ahvays more satisfactory, when practicable, even when Trommer's test affords tolerably decided indica- tions of sugar, to confirm the result by applying also Mau- mene's test (125), the fermentation test (127), and examin- ing under the microscope for the torula (132); since certain other organic matters besides sugar give rise to the forma- tion of the suboxide. 609. When, after having proved the presence of sugar m the blood, it is required to determine its amount, the following method of insulating it is, perhaps, the best, though the results must not be regarded as by any means exact, but merely as an approximation to the truth. The fermentation process (336) cannot be here applied, since traces of carbonic acid may be evolved by some of the ^^constituents °f the blood' when no suSar is present. 610. A known weight of serum is evaporated to dryness either m vacuo over sulphuric acid, or at a very gentle heat on a water-bath. The dry residue is then finely com- minuted, and treated with boiling water, in which it may be allowed to digest for three or four hours, in order to insure the solution of the whole of the soluble matter. The aqueous solution is separated from the albumen by filtration and evaporated to dryness as before. The dr? residue S tiolofthfsaf11 al,COh01' Which leaVGS -disi'd po- tions ot the saline and extractive matters. The alcoholic solution is again evaporated to dryness, and the dry residue treated with ether, which dissolves ou the fat WnTun dissolved the sugar, mixed with a little alcohol extract MORBID BLOOD. 193 and chloride of sodium. This residue is once more dissolved in alcohol, and the alcoholic solution, on being allowed to evaporate spontaneously, aat111 gradually deposit the sugar, mixed with a little chloride of sodium, in the form of small hard crystals. These are to be Avashed Avith a very small quantity of cold Avater, and pressed between folds of filter- ing paper, in order to remove most of the uncrystallizable matter. The mixed crystals of sugar and salt are then dried on a water-bath, and weighed. By careful incinera- tion, the sugar may then be burnt off, leaving the incom- bustible saline matter ; the Aveight of which, Avhen deducted from that of the dry mixture previous to incineration, will represent the proportion of sugar in the quantity of serum used. 611. The quantitative determination of the other con- stituents of blood containing sugar may be effected in the same manner as in the case of healthy blood, the weight of the sugar being deducted from the extractive matter (503, &c.) SECTION X. Blood containing Biliary Matter. 612. In jaundice, and some other affections in Avhich the functions of the liver are interfered Avith, an accumulation of biliary matter is found to take place from the blood, giving the serum a more or less decided saffron or orange- broAvn color, which is due to the peculiar coloring matter of the bile, called biliphaein. 613. The presence of bile in the blood may be detected by adding to a little of the clear serum a few drops of nitric acid, which will throAV doAvn the albumen; the pre- cipitate having, if biliary matter (biliphsein) is present, a decided greenish tint, while in healthy serum it would be white, or very nearly so. 614. If so small a quantity of bile is present as to fail in producing a perceptibly green color with nitric acid, a little of the suspected serum may be first concentrated by evaporation at a temperature not exceeding 120° or 130°, and then exhausted Avith alcohol or Avater, and the solution IT 194 MORBID BLOOD. tested in the manner already described in the case of urme (149-152). 615. We have at present no means of estimating the quantity of biliary matter contained in blood, though the depth of color of the serum furnishes some indication of the relative amount present. The quantitative determina- tion of the other constituents of the blood may be made in the same manner as in the analysis of the healthy fluid (503, &c.) SECTION XI. Blood containing Pus. 616. The existence of pus in morbid blood is probably by no means a rare occurrence, especially in diseases which are attended with suppuration. Its detection, however, is far from easy, since we possess no characteristic chemical test by which it may be distinguished from the ordinary constituents of the blood; and in microscopic appearance, the pus granules very closely resemble the colorless cor- puscles which are always present in the blood (464). The pus granules are in general somewhat larger than the white corpuscles of the blood, and when treated Avith dilute acetic acid, develope internal nuclei, which are usually from three to five in number, and more distinct than those in the white corpuscles of the blood. The pus granules, when present in blood, appear to have a tendency to adhere together in groups of five or six; while the colorless corpuscles of the blood always float detached from each other. 617. According to Heller, the granules of pus, when mixed with blood, subside much more slowly than the blood-corpuscles ; so that when present, they may always be found in the uppermost layer of the coagulum. He recommends a thin slice to be taken from the upper surface of the latter, which, after being mixed with a little distilled water should be filtered through muslin, in order to sepa- rate the fibrin The blood-corpuscles are for the most part dissolved by the action of the water (458); and after allow- ing the filtered liquid to stand a short time in a tall glass the pus granules will be found at the bottom of the liquid and may be detected under the microscope. ' MORBID BLOOD. 195 618. The action of ammonia upon pus has been proposed by Donne as a test for its presence in the blood. When blood, free from pus, is mixed with ammonia, it becomes clear; while if pus is present in any considerable quantity, the liquid becomes more or less gelatinous. If the amount of pus present is small, stringy flocculi only are formed, which subside to the bottom of the liquid. SECTION XII. Blood containing Animalcules. 619. Instances have occasionally been observed, in which minute thread-like animalcules have been present in con- siderable numbers in the blood. Those described by Dr. Goodfellow, Avhich he detected in the blood of a patient suffering from fever, measured from jj^th to 3Aotii of an inch in length, and from ^^th to gouuTJtn 0I> an m^h in diameter. The only method of detecting such entozoa in the blood, is to examine it carefully under the microscope, with as high a magnifying power as the observer has at his command. PAET IT. MILK, MUCUS, PUS, BONE, &c. CHAPTER I. MILK. / SECTION I. General Characters of Milk. 620. Milk, as is well known, is a watery liquid, having in solution a certain amount of casein, sugar of milk, or lactine, and extractive matter, together with several inor- ganic salts, and holding in suspension myriads of extremely minute globules of fatty matter, plainly visible through the microscope, which give the fluid its peculiar Avhite and opaque appearance. It has a pleasant and rather sweetish taste, and a slight agreeable smell, especially while warm. The specific gravity of milk varies considerably ; that of Avoman being sometimes as low as 1020 (the average being 1032), while that of the sheep is as high as 1041. 621. Fresh milk is almost invariably slightly alkaline to test paper, but on exposure to the air, especially in warm weather, it rapidly becomes acid, owing to the conversion of the sugar of milk into lactic acid (HO,C6H505), under the influence of the casein, which acts as a ferment (630). If the milk has been long retained in the mammary glands this change occasionally takes place before being drawn • and m some morbid conditions also, the milk is found to have an acid reaction even when freshly drawn. 622. When allowed to stand for a few hours, the fatty globules, which have a somewhat lower specific gravity than MILK. 197 the fluid portion of the milk, gradually rise to the surface, carrying wTith them a portion of the caseous matter, forming a layer of cream, Avhich is more or less thick and copious in proportion to the richness of the milk. 623. If a little acetic or lactic acid, rennet, or even sour milk, be added to hot milk, the casein of the latter is preci- pitated in the coagulated form ; and the same effect is pro- duced by warming milk or cream which has been allowed to turn sour ; the sourness being due to the lactic acid, into which the sugar of milk has been converted. The solid and liquid portions into Avhich the milk is thus divided, are com- monly called curds and whey. 624. Before describing the mode of analyzing milk, I will briefly notice the several constituents which we find con- tained in it—viz., casein, sugar of milk, fat-globules, and saline matter. SECTION II. Casein. 625. Casein is a modification of protein1 (472) peculiar to the milk, and constitutes the chief source of nourishment to the young animal; for which purpose it is admirably adapted, from the readiness with Avhich it appears capable of being converted into the other modifications of protein—viz., fibrin and albumen. 626. It may be obtained in a state of tolerable purity by evaporating a quantity of milk to dryness on a water- bath, and reducing the dry residue to powder in a mortar. This is then boiled in successive portions of ether, in order to dissolve out the fat. The residue which remains insoluble in the ether is then dried, and digested in water, which will dissolve the casein and other soluble matters of the milk. On adding alcohol to the aqueous solution, the casein is thrown down in the form of a white curdy precipitate, which may be purified by again dissolving it in water, and once more precipitating it by means ot alcohol. ... , ,, 627. It is most probable that pure casein is insoluble, or 1 See note to 471. IV* 198 MILK. very sparingly soluble, in water, and OAves its solubility in milk to the small quantity of alkali which is present. When dry, it closely resembles fibrin and albumen in appearance (479), and its behavior with reagents is in most cases very similar; it differs from the latter chiefly in not coagulating when heated; and it is precipitated by acetic, and nearly all the acids, but redissolves in a con- siderable excess of most of them. The ferrocyanide and ferridcyanide of potassium also cause precipitates in solu- tions of casein. SECTION III. Sugar of Milk, or Lactine (C24H24024). 628. The sugar contained in milk may be prepared in the following manner:—The curd, including the greater part of the casein and fat globules, is first separated by the addition of a few drops of acid to hot milk, and the remain- ing traces of those substances are then removed by mixing a little Avell-beaten white-of-egg Avith the whey when cold, and afterwards boiling the mixture. The whey, thus clarified by the coagulating albumen of the egg, is filtered from the precipitate by passing it through muslin or calico ; and the clear liquid may then be evaporated to about one- fourth or one-fifth its bulk, and set aside in a cool place for a few days. The sugar will gradually separate from the liquid, in the form of minute hard crystals, Avhich adhere to the surface of the containing vessel. These may be purified by dissolving them again in water, boiling the solution with animal charcoal, and recrystallizing. 629. This variety of sugar is less sweet than that obtained either from the cane or the grape (114); it is also harder, and less soluble in water, requiring as much as five or six times its weight of cold, and two and a half times its weight of hot water to dissolve it. When mixed with a little hydrochloric or sulphuric acid, sugar of milk gradually becomes converted into grape sugar (C12HuOuY and this change takes place more rapidly if the solution^ boiled milk thiYf / mfluenceJof the caseous matter of the umrZnT Tgar gradua1^ Passes int0 i«*i° acid {JiU^H.O,}, a change easily accounted for, since the MIL K. 199 formula of the sugar is a multiple of that of the acid, one equivalent of the former being broken up into four of the luttGr C2iH2i02i=4(HO,C6ffb0.0). SECTION IV. Fat Globules. 631. The minute globules which are held suspended in milk, and to which the opacity and Avhiteness of the fluid are due, consist mainly of oily fat, which appears to be surrounded by a thin covering of insoluble matter, differing in its properties from fat, and probably composed of one of the modifications of protein (472). 632. The size of the globules in healthy milk varies from a mere point to about s^outi1 of an inch in diameter, the average size being rather more than ^o\)atn C^g* 65). 633. In the milk which is secreted during the first feAv days of lactation, called the colostrum, and which is always much richer in quality than ordinary milk, we find, in addition to the common milk globules, numerous granular corpuscles of a pale yelloAvish color, and considerably larger than the others, their diameter varying from 2 0Vuta to 5 o ntn of an inch (Fig. 66). Similar corpuscles are also occasion- Fig. 65. Fig- 66. Milk Globules. Colostrum Corpuscles. ally present in milk secreted during disease. They appear to be almost peculiar to human milk, being rarely met Avith in that of the cow and other animals. 634. The fatty matter of milk consists for the most part of a solid fat, called margarine (C74H74012), mixed with a 200 M ILK. liquid fat or oil, called oleine (C7sH7,013), together Avith small quantities of butyrine and other fats. The proportion in which these several fats are found mixed in milk varies considerably, being influenced by the health and food of the individual, the season of the year, and other circum- stances. A specimen of the fat contained in cow's milk, analyzed by Bromeis, contained— Margarine, ........ 68 Elaine,.........30 Butyric, caproic, and capric acid, .... 2 100 SECTION V. Saline Matters. 635. It is probable that the following salts are present in milk, though an analysis of the ash will not, of course, detect the organic and volatile compounds included in the list, since they are either decomposed or volatilized during the process of incineration:—the chlorides of potassium and sodium; the phosphates of potash, soda, lime, and mag- nesia, with traces of phosphate of the peroxide of iron ; and the lactates of potash, soda, lime, magnesia, and probably of ammonia. 636. According to Haidlen, the ash obtained by incine- rating 1009 parts of cow's milk, consisted, in two instances, of the following substances : Phosphate of lime, Phosphate of magnesia, Phosphate of peroxide of iron, Chloride of potassium, Chloride of sodium, Soda, .... I. n. 2-31 3-44 0-42 0-64 0-07 0-07 1-44 1-83 0-24 0-34 0-42 0-45 4-90 6-77 637. The presence of these several salts may be proved by applying to a solution of the ash in water and hydro- ch one acid the tests mentioned in the chanters on to urine and the blood (41, 490 &c ) cnaPteis on the MILK. 201 SECTION VI. Composition of Human Milk. 638. In healthy human milk, the several constituents which I have now briefly described, are not always present in the same relative proportions ; various circumstances, as those of age, temperament, and food of the mother, as well as the period of lactation, causing considerable variations in the composition of the secretion. The following examples will serve to show to what extent these variations usually occur. Analysis I. (Simon.) Showing the Mean of Fourteen Analyses made at different periods, with the Milk of the same Woman. Water,.........883-6 Solid constituents,.......116-4 Butter,.........25-3 Casein, .....•••• 343 Sugar of milk and extractive matters, . . . 48*2 Fixed salts,........2'3 Analyses II, III, & IV. (Clemm.) The fourth day The ninth day The twelfth day after delivery. after delivery. after delivery. 879-848 885-818 905-809 120-152 114-182 94-191 42-968 35-316 33-454 35-333 36-912 29-111 Water, Solid constituents, Butter, . Casein, . Sugar of milk and extractive matters, Salts, 41-135 2-095 42-979 1-691 Analyses V & VI. (L'Heretier.) Water, . Solid constituents, Butter, Casein, Sugar of milk, Salts, . 867-8 132-2 42-5 11-7 74-0 4-0 31-537 1-939 870-6 129-4 520 9-5 63-4 4-5 Analysis VII. (Chevallier and Henri.) Water, . Solid constituents, Butter, Casein, Sugar of milk, Salts, 879-8 120-2 35-5 152 650 45 202 BULK. The recent analyses of MM. Vernois and Alfred Bec- querel give the following as the composition of normal human milk: Water,........889'08 Sugar,........43-64 Casein and extractive, ..... 39'24 Butter,........26-66 Salts (ash),....... 1*38 1000-00 Specific gravity, 1032-67. SECTION VII. Composition of the Milk of other Animals. 639. The proportion of the several constituents is found to differ considerably in the milk of different animals. The subjoined table, showing the composition of the milk of a few of the more important domestic animals, from the ana- lyses of Chevallier and Henri, will serve to illustrate this : Casein, Butter, Sugar of milk, Saline matter, Water, Cow. Ass. Goat. Ewe. 4-48 1-82 4-08 4-50 3-13 o-n 3-32 4-20 4-77 6-08 5-28 5-00 0-60 0-34 0-52 0-68 87-02 91-65 86-80 85-62 100-00 100-00 100-00 100-00 CHAPTER II. QUANTITATIVE ANALYSIS OP MILK. 640. Two portions of milk, one weighing about 100 wrhe/fhefi^-11" *??m grain^-to Laccltely weighed, the first in a platinum crucible or capsule and tbp second in a porcelain capsule ; both the vesselsWW W previously weighed or counterpoised. The tsfportln of MILK. 203 100 grains we will call A, and the second, of 400 grains, we will call B. 041. Treatment of the portion A.—This portion, after being weighed, is to be evaporated to dryness on a water- bath, or, still better, on a chloride of calcium bath heated to about 220°, until, on being weighed at intervals of half an hour or an hour, it ceases to lose any further weight. The weight of the dry residue will then represent the amount of solid matter contained in the quantity of milk used, while the loss of weight during evaporation shows the amount of water. 642. In these and the other determinations, the propor- tion present in 1000 parts of the milk is calculated in the following manner : Wt. of milk 1 I Wt. of each 1 f Proportion of that con- 1 used in the > : J constituent j : : 1000 : J stituent in 1000 parts } experiment. ) ( obtained. ) (of the milk. ) 643. The weight of the dry residue having been noted, the crucible, with its contents, is to be placed over a lamp, and kept at a red heat until the whole of the charcoal is burnt away, and the ash becomes white or nearly so. The weight of the ash thus obtained will represent the amount of inorganic saline matter in the quantity of milk eva- porated, from which the proportion in 1000 parts may be calculated as before (642). 644. Treatment of the portion B.—This portion, after being weighed, is to be mixed with about one-fourth its weight of finely-pounded hydrated sulphate of lime (CaO, S03+2Aq) or unburnt gypsum, with which it is to be well stirred for a short time, and then raised to a temperature of 212° ; by which means the whole of the casein will be- come coagulated, and insoluble in water. The mixture is noAV to be evaporated to dryness on a water-bath, being oc- casionally stirred, in order that the solid residue of the milk may be pretty uniformly mixed with the sulphate of lime. 645. The mass, when dry, is then easily reduced to pow- der ; after which it is to be digested with successive small quantities of ether, which will dissolve out the whole of the fatty matter. The ethereal solution is now eA'aporated to dryness on a water-bath, and the residue weighed; its weight representing the amount of FAT in the quantity of 204 milk during disease. milk operated on; from Avhich the proportion present in 1000 parts of milk may be calculated as before (642). 646. The portion of the residue AAdiich proved insoluble in ether (645) is now to be treated with hot alcohol, as long as anything dissolves. In this wTay, the Avhole of the sugar, together ivith a little saline matter and alcohol-extractive, is dissolved. The alcoholic solution is to be evaporated to dryness on a water or chloride of calcium bath, and the dry residue having been accurately weighed, is incinerated; the difference between the weight before and after incine- ration will then represent the quantity of sugar, with a little alcohol extractive matter, in the portion of milk em- ployed. The proportion contained in 1000 parts is then calculated as in the former cases (642). 647. The remaining portion of the dry residue, which resisted the action of the alcohol (646), is to be dried on a water, or chloride of calcium bath, weighed, incinerated, and the weight of the ash ascertained. The loss of weight during incineration will represent the amount of casein, with a little water extractive matter, in the quantity of milk used, from Avhich the proportion in 1000 parts may be determined as before (642). 648. The proportion of casein may also be estimated by adding together the amount of water, fat, sugar, and saline matter, already ascertained as being present in 1000 parts of the milk, and deducting the sum of them from 1000. The experimental determination is, however, to be preferred! CHAPTER III. milk during disease. 649. The milk which is secreted during disease is usually more or less modified in its composition; even slight de- rangements of the system, and any great mental fnxiety or sudden emotion of fear, &c, not unfrequently have the effect of disturbing in a remarkable manner, the natural character of the secretion. The exact naturo? these changes is very imperfectly understood. They are mo bably sometimes merely variations in the relativepro£o/ milk during disease. 205 tions of the several constituents of the healthy fluid; at others, and perhaps more frequently, certain abnormal matters are formed. 650. With the assistance of the microscope, we are not unfrequently able, with great facility, to detect the presence of certain morbid products which are not found in the healthy secretion. The peculiar form of milk called the colostrum, which is secreted during the first few days of lactation, has been already mentioned as differing very con- siderably in microscopic appearance from healthy milk, and as containing numerous granular corpuscles, much larger than the ordinary milk-globules (633). The corpuscles of the colostrum also shoiv a tendency to adhere to each other, while the globules of the healthy fluid usually float freely about. It occasionally happens that the milk, instead of changing, in the course of a few days, to its more natural condition, continues for a length of time to possess the characters peculiar to colostrum; and has even been ob- served to change back again to this condition, after being secreted for a time in a healthy state. The presence of the colostrum corpuscles (Fig. 66), and the slightly viscid appearance also characteristic of this condition, may at once be detected under the microscope. 651. The presence of pus, Avhich during the formation of a mammary abscess often finds its way into the milk, may also be detected under the microscope, by the occurrence of the peculiar pus-granules (Fig. 67). Blood-corpuscles, too (451), are also found, though more rarely than those of pus, owing, in most cases, to the rupture of some of the Fig. 67. Fig. 6S- S© e£fi?~ u &7&P Pus in Milk. Blood in Milk. minute bloodvessels with Avhich the mammaryg land is per- meated (Fig. ('s). 18 206 T II K A D I L T E R A T 10 N S OF M I L K 652. In addition to the strictly morbid products, other substances, especially certain salts, which have been taken into the system either in the food or as medicine, appear occasionally to find their way into the milk, where they may sometimes be detected by the proper tests. Analysis of the Colostrum of a Woman together with that of the Healthy milk of the same individual. (Simon.) Water, Solid constituents Fat, Casein, . Sugar of milk, Saline matter, 1 t Healthy ) s rum. Milk. 828-0 887-6 172-0 122-4 50-0 25-3 40-0 34-3 70-0 48-2 3-1 2-3 CHAPTER IV. THE ADULTERATIONS OF MILK. 653. It is well known that much of the milk which is supplied in large toAvns is almost constantly more or less adulterated, and although the substances employed for the purpose are in most cases comparatively innoxious, it is much to be wished that some simple and efficient test of its genuiness and purity could be devised, capable of being applied by those who are unaccustomed to experiment. 654. The substances most commonly used for the pur- pose of adulteration appear to be water, flour, starch, and finely-pounded chalk ; and besides these, the macerated brains of sheep and other animals are said to be sometimes introduced. All these, with the exception of the first, may be easily detected. ' J 655. On examining a little of the milk under the micro- scope the peculiar granules of starch and flour may be ItJJey ft* 6? f these is by no means clearly ascertained. SECTION II. Quantitative Analysis of Mucus. 664 The quantitative determination of the principal con- stituents of mucus may be made in the following manner. The mucus intended for analysis is first divided into two portions, A and B ; the first, A, being about one quarter, and the second, B, about three quarters, of the whole. 18^ 210 QUANTITATIVE A N A L \ S I S OF MUCUS. Both portions are to be weighed in counterpoised capsules, that containing A, being of platinum, and evaporated to dryness on a chloride of calcium bath, at a temperature of about 220°. 665. Treatment of the portion A.—This portion, after being dried until it ceases to lose weight, is to be accurately weighed. The Aveight of the dry residue gives the amount of solid matter in the quantity of mucus evaporated, while the loss represents the amount of WATER. 666. The proportion of these and the other ingredients contained in 1000 parts of the mucus, may in each case be estimated by the folloAving calculation : {Weight of A ( Wt. of each con- A f Proportion of that A mucus [ _ J stituent contained [ mnn J constituent con- before eva- r • A in the quantity of f :: iu"" : A tained in 1000 parts f poration. J [ mucus employed J I of mucus. j 667. The dry residue is then to be incinerated at a low red heat, until the ash becomes white, or nearly so. The weight of the ash will then represent the amount of saline matter in the quantity of mucus used; from which the proportion present in 1000 parts may be calculated as be- fore (666). 668. Treatment of the portion B.—The dry residue left after evaporation (664) is to be removed from the capsule, and reduced to fine powder in a mortar. It is then boiled with successive small portions of ether, which will dissolve out the fat. The ethereal solution is evaporated to dryness on a water-bath, when the Aveight of the residue will indi- cate the amount of fat in the quantity of mucus employed • from which the proportion in 1000 parts maybe estimated as before (666). tJo?' The*esidue wnich proved insoluble in the ether (668) is to be boiled with a little alcohol, after which the alcoholic solution is to be evaporated to dryness, and the dry residue weighed. This is then incinerated, and the weight of the ash, deducted from that of the dry extract will give the amount of alcohol extractive, with the lactic acid of the lactates, in the quantity of mucus used • £n ^ corrected, as before, for 1000 parts (666) ' 670. Ihe portion of the residue Avhich proved insohVhlp m the alcohol (669) is to be dried and weigLd thS indicating he amount of mucin, together with cdlSar matter, and probably traces of albumen, in the quantit^ MORBID MUCUS. 211 of mucus employed; from which the proportion present in 1000 parts of mucus may be calculated, as in the former cases (666). 671. According to Nasse, the composition of fresh pul- monary mucus is as follows : Water, .... 955-520 Solid constituents, . 44-480 Mucin, with a little albumen, 23-754 Water extract, 8-006 Alcohol extract, 1-810 Fat, .... 2-887 Chloride of sodium, 5-825 Sulphate of soda, 0-400 Carbonate of soda, . 0-198 Phosphate of soda, . 0-080 Phosphate of potash, with traces of ron, 0-974 Carbonate of potash, 0-291 Silica, and sulphate of potash, 0-255 SECTION III. Morbid Mucus. 672. The characters of mucus secreted during disease are usually more or less different from those of the normal secretion, and an admixture of foreign matters frequently alters its appearance considerably. Pus, for instance, when mixed with it, diminishes its tenacity, owing to the mucin being present in smaller proportion (663); and when the liquid portion of mucus containing an admixture of pus is tested for albumen (254, 677), a considerable amount of that substance may usually be detected; since the liquor puris, or liquid portion of pus, contains a comparatively large quantity of albumen, but no mucin. Our means of detecting the presence of minute traces of pus in mucus are very imperfect; the decided presence of albumen in the purulent secretion is, indeed, almost the only test, since the microscopic characters of the corpuscles appear to be identical in both (249). 673. The morbid mucus expectorated in pulmonary dis- ease frequently contains, besides pus, red blood-corpuscles, minute globules of fat, fragments of tuberculous matter, and other abnormal substances, most of which may gene- rally be detected without difficulty under the microscope. 212 GENERAL CHARACTERS OF PUS. The indications afforded by a careful microscopic exami- nation of such expectorations, indeed,.may often lead to results in diagnosis, of great importance to the practical physician. CHAPTER VI. PUS. SECTION I. General Characters of Pus. 674. Pus is the peculiar semifluid matter which is formed in abscesses, and in other kinds of wounds. In common language, a considerable variety of substances, more or less resembling each other in appearance, though differing in many respects, are included under the name of pus; and hence it has been found necessary to distinguish the normal secretion by the name of true or genuine pus; the other substances being called spurious ox false pus. 675. Normal pus is a thick, creamy-looking fluid, per- fectly opaque, and usually of a pale yellow or greenish color. It possesses litle or no tenacity, and may conse- quently be poured in separate drops; in which respect it diflers essentially from mucus, which in color and general appearance it often much resembles. Its specific gravity is usually about 1030 or 1033, so that it sinks in water ; and if shaken up with that fluid, mixes uniformly with it The mixture, after standing a short time, gradually deposits a sediment, consisting of the pus corpuscles (678). It is most tThTL116^1 t0,te?J paPer' ^ also occasionally nie with slightly acid and alkaline. * 676. Like mucus, pus consists of a clear fluid portion or serum, m which float innumerable minute granular cor puscles, which latter appear to be almost preciily the same" as those contained in mucus, and when examinedunderZ microscope, exhibit the same granular apJZl^The i« us. 213 liquid portion of pus, or liquor puris, however, differs essen- tially from the fluid portion of mucus, and contains the following substances in solution, which, it will be seen, are nearly the same as those held in solution in the serum of the blood (573)—viz., albumen, together with a peculiar compound called pyin, or tritoxide of protein, which is soluble in water, and precipitated by acetic acid, fat, ex- tractive matters, and inorganic salts. These latter consist, for the most part, of chloride of sodium, with small quan- tities of phosphate, sulphate, and carbonate of soda ; the chlorides of potassium and calcium ; phosphates and car- bonates of lime and magnesia; and traces of peroxide of iron. 677. The presence of these matters in the liquor puris may be shoAvn by placing some pus in a tall narrow glass, and allowing it to stand, in order to give the corpuscles time to subside ; after Avhich, a little of the clear liquid may be drawn off Avith a pipette. On boiling a feAv drops of this in a test tube, the albumen becomes coagulated, and separates from the liquid ; after Avhich the pyin may be thrown down in the form of a Avhite flocculent precipitate, "by adding a little acetic acid. The liquid may then, if ne- cessary, be tested for the several inorganic salts above enu- merated (676, 490). 678. The pus-corpuscles though quite invisible to the naked eye, may be distinguised under the microscope Avith a magnifying poAver of from fifty to one hundred diameters ; a considerably higher poAver, however, is required for exhi- biting their peculiar granular structure (Fig. 70, a). The size Fis-70- of these corpuscles varies consi- @« ^ @ QQOQ derably, being commonly about fN^ $©4*fl| TJJiffffth of an inch in diameter. /^Xp^Q S2JP Thev are nearly spherical; and ^||*§ 0| ^Jijg have a very pale yellowish color, *© % % w W @ AA'hich is SCai'CelAT perceptible, Un- Pus-corpuscles, magnified 400 cliam. less several of them are aggregated _ together. Being slightly heavier than the liquor puns with ' which they are surrounded, they gradually subside to the bottom, leaving the fluid portion nearly clear. Minute globules of fat may usually be detected, mixed with the corpuscles. 214 PUS. 679. The pus-corpuscles, when treated with liquids of different densities, exhibit the phenomena of endosmosis and exosmosis, somewhat similar to those already described as taking place in the corpuscles of the blood (456); in- creasing in size when the external liquid, such as pure water, is of lower density, and collapsing when it is of higher density, than the fluid contained in them. When treated Avith dilute acetic acid, the external covering be- comes transparent, and exhibits one or more internal nuclei (Fig. 70,5). 680. When mixed with a solution of ammonia, pus loses its fluidity, and assumes a jelly-like appearance, Avhich is highly characteristic. A somewhat similar effect is pro- duced also by the alkaline carbonates, and certain other salts. 681. Although the general appearance and characters of pus are usually sufficiently marked to enable us to identify it, it is always advisable, in cases where any doubt exists, to submit it to microscopic examination ; since occasionally we meet with fluids containing a large quantity of epithe- lium and other products, Avhich, in appearance closely re- semble pus, though differing entirely in composition from*' that substance, and containing no trace of the characteristic pus-corpuscles (678). The form of these corpuscles is found to vary considerably under certain pathological conditions ; but there may generally be traced sufficient resemblance to the normal corpuscles to enable us to distinguish them from other matters. The modes of distinguishing between pus and mucus, have been already noticed in paragraphs 248, &c. SECTION II. Quantitative Analysis of Pus. 682. The quantitative analysis of pus may be made in the following manner :—Two portions of the fluid are to be weighed out; the first, A, in a small counterpoised flask • and the second, B, in a counterpoised or weighed evapo- rating dish. r ■ 683. Treatment of the portion J..—-The portion A, after being weighed in the flask, is to be boiled with successive PUS. 215 small quantities of strong, or absolute alcohol, which must be separated while hot, either by filtration or decantation, from the insoluble portion. The alcoholic solution is then set aside to cool, and alloAved to stand a feAv hours, in order that the fat may, for the most part, crystallize out. The cold alcoholic liquid is then poured off, and the solid matter dried and weighed; when the weight thus obtained will represent the amount of FAT in the quantity of pus em- ployed in the experiment. 684. The cold alcoholic liquid (683) is now to be evapo- rated to dryness in a counterpoised platinum capsule, and the dry residue, after being weighed, is incinerated. The weight of the ash is then ascertained, when the difference betAveen the weight before and after incineration will repre- sent the quantity of extractive matter (together with traces of fat Avhich had not separated from the cold alcohol), in the portion of pus employed. 685. The residue Avhich proved insoluble in the boiling alcohol (683), is to be dried on a water-bath, and then boiled Avith a little Avater, Avhich will dissolve out the pyin, and at the same time cause the coagulation of the albumen. The aqueous solution thus obtained is to be separated from the insoluble portion; evaporated to dryness in a platinum capsule on a Avater-bath; and the Aveight of the dry residue having been noted, it is to be incinerated. The difference between the Aveight of the dry residue previous to incine- ration, and that of the inorganic ash, represents the amount of pyin in the portion of pus used in the experiment. 6^6. The matter AA'hich remained insoluble in the hot water (685), is now to be dried and Aveighed. The dry residue is incinerated ; and the loss of Aveight which it experiences during incineration will show the amount of albumen and corpuscles in the quantity of pus operated on. 687. Treatment of the portion B.—The weight of this portion having been noted, it is to be evaporated to dry- ness on a chloride of calcium bath, at a temperature of about 220°, the heat being continued until it ceases to lose Aveight on being Aveighed at intervals of half an hour or an hour. The loss of Aveight during the evaporation Avill then represent the proportion of avater in the quantity of pus 216 PUS. employed ; while the weight of the dry residue shows the amount of solid matter. 688. The dry residue is now to be incinerated in a pla- tinum capsule or crucible, until the ash becomes Avhite or pale gray. The weight of the ash will then show the amount of inorganic saline matter in the quantity of pus used in the experiment. 689. The proportion of the several constituents contained in 1000 parts of pus, may then be estimated from the num- bers obtained in the above experiments, by the following calculation : Wt. of pus used in the experiment. ) ( AVt. of each ) ( [ : J constituent } : : 1000 : J ) ( obtained. ) ( Proportion of that constituent in 1000 parts of pus. 690. From the analysis of Dr. Wright, the composition of pus appears to be as follows : Pus from Pus from a Dsoas Pus from a a vomica. abscess. mammary abscess. Water, .... . 894-4 885-2 879-4 Fatty matter, Cholesterin, . . 17-5) 5-4] 28-8 26-5 Mucus, . 11-2 6-1 Albumen, . 68-5 63-7 83-6 Lactates, carbonates, and ) phosphates, of soda, pot- r- 9-7 135 8-9 ash, and lime, . j Iron, .... a trace. Loss, .... 3-3 2-7 1-6 CHAPTER VII. BONE. SECTION I. General Characters of Bone. 691. The color, texture, specific gravity, and general characters of bone, differ very much in different parts of the body ; and the proportions of the several chemical in- general characters of bone. 217 gredients are also found to vary considerably. The two principal constituents of bone are cartilage (C9GH82F150.i6), and phosphate of lime (8CaO,3P05); the proportion of the first being usually about 29 to 34 per cent., and that of the latter from 50 to 60 per cent, of the entire bone. The other substances which are present in smaller quantity, are carbonate of lime (CaO,C02); phosphate of magnesia (2MgO,HO,P05); fluoride of calcium (CaF); soluble soda salts, chiefly chloride of sodium; traces of the oxides of iron and manganese; and fat; which latter, however, does not belong strictly to the bone, but to the marroAv contained in it. The presence of these several substances may be demonstrated by the following experiments. 692. The cartilaginous matter of bone may be obtained almost entirely free from the saline and other ingredients, by digesting a bone for a day or two, at a temperature not higher than about 50°, in dilute hydrochloric acid, composed of about one part of the strong acid and five parts of water. The earthy and saline matters gradually dissolve in the acid, leaving the cartilage unaffected, and still retaining the exact form of the bone. In this state it is soft and elastic; be- coming, Avhen dried, hard, somewhat brittle, and horny in appearance. 693. If the cartilage be boiled for some time in Avater, it Avill almost wholly dissolve, being converted into gelatine (C0liHS2NVjO.i6); leaving undissolved nothing more than a delicate network of vessels. The aqueous solution thus obtained becomes, unless very dilute, gelatinous on cooling. 694. The fat may be separated by boiling a feAv fragments of crushed bone with ether, and evaporating the ethereal solution ; when the fat will be left behind as a residue. 695. The phosphate of lime and phosphate of magnesia may be isolated by dissolving a fragment of calcined bone in dilute hydrochloric acid, and supersaturating the acid solution with ammonia; Avhich will throAV doivn a white gelatinous precipitate of the mixed earthy phosphates. If this precipitate be examined under the microscope, it will be found to be chiefly composed of amorphous particles of phosphate of lime, mixed with a small quantity of the crvstalline double phosphate of ammonia and magnesia 19 218 BONE. (2MgO,NH40,P05+12Aq), showing the presence of phos- phate of magnesia. 696. The presence of carbonic acid (carbonate of lime) may be proved by the effervescence which ensues when a fragment of uncalcined bone is moistened Avith dilute hydro- chloric acid. If the solution, filtered from the precipitate of earthy phosphates (695), be tested with oxalate of am- monia, it AA'ill be found still to contain a considerable amount of lime (475), which existed in the bone as carbonate; since that portion only of the lime was precipitated by the am- monia, which Avas in combination with phosphoric acid. 697. If calcined bone, reduced to powder, be boiled for some little time in a test tube or glass flask, with a little rather dilute sulphuric acid, consisting of about equal parts of the strong acid and water, the inner surface of 'the glass will generally be found to be slightly corroded, owing to the disengagement of hydrofluoric acid (hf) by the action of the sulphuric acid on the fluoride of calcium. GaR+HO, AS'03=CaO,S03+HF. This substance, however, does not appear to be invariably present in bone, and some observers have been unable to detect it. 698. The presence of chloride of sodium may be shown by boiling a little calcined bone reduced to powder with water, filtering from the insoluble earthy portion, and testing a feAv drops of the aqueous solution with nitrate of silver, which will give an abundant precipitate of the chloride ^ gi?l* i,By concentrating the rest of the solution to a small bulk, and testing it with antimoniate of potash, a white crystalline precipitate of antimoniate of soda (NaO, «rJoW1 £"! J appear' showing the presence of soda. o9J. A little sulphate of soda may also be detected, by means of chloride of barium (41 c), in the soluble portion of calcined bone, though no trace of sulphuric acid is to be tound in it previous to calcination; being produced during ignition, by the oxidation of the sulphur contained in the T/1SSU6S* SECTION II. Quantitative Analysis of Bone. 700. About three hundred grains of the bone intended for analysis should be first cleaned from adhering fat, peri QUANTITATIVE ANALYSIS OF B 0 N E. 219 osteum, and other impurities, and then reduced to tolerably small fragments either by crushing or rasping. 701. Treatment of the first portion.—One hundred grains of the bone are to be dried in a counterpoised platinum capsule or crucible, on a chloride of calcium bath, at a temperature of about 250°, until it ceases to lose weight on being weighed at intervals of half an hour or an hour. The loss of weight Avhich it experiences during desiccation represents the percentage of avater. 702. The dry mass is now to be incinerated in the capsule at a low red heat, until the whole of the organic matter is burnt away, and the ash becomes throughout perfectly Avhite. The weight of this ash gives the percentage of inorganic matter contained in the bone; while the loss during incineration represents the percentage of organic matter. The inorganic residue may then be digested in dilute hydrochloric acid, and retained for subsequent exa- mination (706). 703. Treatment of the second portion.—A second portion of the crushed or rasped bone, weighing one hundred grains, is to be digested for a day or two, in cold dilute hydrochloric acid, containing one part of the strong acid to five or six of Avater; the whole being kept at a temperature not higher than about 50°, as otherwise some traces of the animal matter of the bone would be acted upon by the acid. The Avhole, or at least by far the greater portion of the in- organic matter is thus dissolved, and when the acid liquid has been Avell Avashed out of the insoluble residue by means of cold water, little will remain but the cartilaginous matter of the bone. 704. The cartilaginous residue is to be evaporated to dryness, or nearly so, on a Avater-bath, and then boiled with a little ether, which must be poured off, and renewed if necessary, until all the fat is dissolved. The ethereal solu- tion is then evaporated to dryness in a counterpoised capsule on a Avater-bath; Avhen the weight of the residue will give the percentage of FAT in the bone. 705. The matter which proved insoluble in the ether (704), consisting chiefly of cartilage, wdth traces of inorganic matter, is noAv to be dried on a chloride of calcium bath, at a temperature of about 250°, Aveighed and incinerated. 220 BONE. The difference between the weight of the dry residue before and after incineration, will then represent the percentage of cartilage in the bone. 706. The ash left after the incineration of the first hundred grains of bone (702) is now to be dissolved^ in moderately dilute hydrochloric acid; a gentle heat being applied if necessary. The acid solution is then slightly supersaturated with ammonia, which will throw down the phosphate of lime, together with the small quantity of phosphate of magnesia and fluoride of calcium ; as well as any traces of peroxide of iron and oxide of manganese that may be present. The precipitate is to be well washed, fil- tered, dried, and ignited; after which its weight will repre- sent the amount of bone earth, consisting of phosphate OF LIME Avith PHOSPHATE OF MAGNESIA, and FLUORIDE OF calcium, in one hundred parts of the bone. 707. If it is required to determine separately the pro- portion of phosphate of magnesia, the ignited precipitate (706), after being weighed, is to be redissolved in dilute hydrochloric acid; the acid solution is then mixed with an excess of perchloride of iron (Fe2Cl3), and supersaturated with ammonia. The phosphoric acid of the earthy phos- phates is thus precipitated in combination with peroxide of iron, together with any excess of uncombined peroxide of iron, leaving in solution the chlorides of calcium and magnesium.1 The lime (chloride of calcium) is first preci- pitated by adding oxalate of ammonia (NH^O^O^), as long as it causes a precipitate, boiling the mixture, and filtering. The filtered solution is then concentrated by evaporation, and the magnesia thrown down by adding phosphate of soda (2NaO,HO,P05), and a decided excess of ammonia. The mixture is allowed to stand for some hours, after which the precipitated double phosphate of ammonia and magnesia (2MgO,NH40,P05+12Aq) is to be filtered, dried, and ignited, by which it is converted into phosphate of magnesia (2MgO,P05), and weighed. This Aveight will represent the amount of phosphate of mag- nesia in the 100 grains of bone; which, when deducted from the whole earthy phosphates (706), will give the per- centage of phosphate of lime. 1 See Introduction to Practical Chemistry, second edition, p. 159. quantitative analysis of bone. 221 708. The solution filtered from the precipitate of earthy phosphates (706), containing the portion of lime which existed in the bone as carbonate, is now to be treated with oxalate of ammonia as long as any precipitate is produced. The whole of the lime is thus separated as oxalate (CaO, C20.,-| 2Aq), which, after boiling the mixture, is filtered, dried, and ignited. The oxalate is converted, during the ignition, into carbonate (CaO,C02), so that the weight of the ignited precipitate will represent the amount of car- bonate of lime in the hundred grains of bone. 709. As a check upon the estimation of the carbonate of lime, the amount of carbonic acid in the bone may be de- termined by placing 100 grains of the un- burnt bone in fine powder, in a flask a, provided with a desiccating tube b, con- taining fragments of chloride of calcium (Fig. 71). A test tube c, containing hydro- chloric acid, is then placed in the flask, and the Avhole apparatus is weighed ; after which the acid is allowed to flow gradually upon the powder, from which it will expel the carbonic acid. The amount of the latter, which, being gaseous, escapes in a dry state through the chloride of calcium tube d, is then represented by the loss of Aveight which the apparatus with its contents experiences during the experi- ment (337). It Avill probably be found that the carbonic acid thus determined, bears to the carbonate of lime (708) the proportion of 22 to 50, those being the atomic Aveights of carbonic acid and carbonate of lime respectively. 710. The solution filtered from the oxalate of lime (708) Avhich contains the soluble salts (chiefly chloride of sodium) together with the excess of oxalate of ammonia employed to precipitate the lime, is noiv to be evaporated to dryness, and the residue ignited in order to expel the ammoniacal salts. The weight of the residue after ignition will then represent the percentage of soluble saline matter. 711. The following analyses Avill serve to illustrate the composition of bone, both of man and some of the lower animals. 19* 222 BONE. Analysis I. (Von Bibra.) Showing the Composition of the Bones of a Child two months old. Phosphate of lime, with a little fluoride \ of calcium,.....j Carbonate of lime,..... Phosphate of magnesia, - Soluble salts, ------ Cartilage,...... Fat,....... Tibia. Ulna. 57-54 56-35 6-02 6-07 1-03 1-00 0-73 1-65 33-86 34-92 0-82 101 Analysis II. ( Von Bibra.) Composition of the Bones of a Middle-aged Man. Femur. Tibia. Humerus. Costa. Phosphate of lime with a little fluo- - 59-63 58-95 59-87 55-66 ride of cal- cium, Carbonate of] lime, j 7-33 7-08 7-76 6-64 Phosphate of j magnesia, j 1-32 1-30 1-09 1-07 Soluble salts, 0-69 0-70 0-72 0-62 Cartilage, - 29-70 30-42 29-28 33-97 Fat, - 1-33 1-55 1-28 2-04 Analysis III. (Berzelius.) Composition of Human Bone. Phosphate of lime,...... 51-04 Fluoride of calcium, ----.. 2-00 Carbonate of lime,......11-30 Phosphate of magnesia, ----- \.\q Soda, with a little chloride of sodium, - - 1-20 Cartilage, -----.. 32-17 Vessels,........^.-.^ MORBID BONE. 223 Analysis IV. (Von Bibra.) Composition of the Bones of Lower Animals. Femur of Femur of Femur of Humerus of sheep aged bull aged horse aged cat aged 4 years. 4 years. 6 years. 6 years. Phosphate of" lime with a ^ little fluo- - 55-94 54-07 54-37 59-30 ride of cal- cium, Carbonate of lime, ► 12-18 12-71 12-00 10-69 Phosphate of 1-00 1-42 1-83 1-70 magnesia, 1 Soluble salts, . 0-50 0-80 0-70 0-40 Cartilage, . . 29-68 29-09 27-99 27-21 Fat, . . 0-70 1-91 3-11 0-70 Vertebrne Humerus Vertebrae Vertebrae of dolphin. of thrush. of snake. of salmon. Phosphate of \ lime with a little fluo- [ 52-51 62-65 59-41 36-64 ride of cal- cium, 1 Carbonate of !■ 9-37 60-5 7-82 1-01 lime, I Phosphate of [■ 0-98 0-90 1-00 0-70 magnesia, J Soluble salts, - 1-24 0-84 0-73 0-83 Cartilage, - 33-97 28-02 24-93 21-80 Fat, - - 1-54 6-11 38-82 SECTION III. Morbid Bone. 712. Certain diseases are found to be always accompanied by remarkable changes in the chemical composition of the bones ; the earthy matter being sometimes so deficient, that they no longer possess the rigidity and strength necessary for sustaining the weight of the body. Other variations also, are occasionally met with, a few examples of which are subjoined. 224 QUANTITATIVE ANALYSIS OF BONE. Analyses of the Tibice of three Rachitic Children. (Lehmann.) Phosphate of lime, Carbonate of lime, Phosphate of magnesia, Chloride of sodium, - Soda, Cartilage, - Fat, ---. I. 32-04 4-01 0-98 0-21 0-54 54-14 5-84 II. 26-94 4-88 0-81 0-27 0-81 60-14 6-22 Analyses of Bone in Osteomalacia. (Prosch.) Phosphate of lime, - Carbonate of lime, - Sulphate of lime and phosphate of soda, Cartilage, - Fat, - - . . . Vertebra. 13-25 5-95 0-90 74-64 5-2G III. 28-13 3-75 0-87 0-28 0-73 58-77 6-94 Costa. 33-66 4-60 040 49-77 11-63 Analyses of Carious Bone. ( Valentin.) Vertebra? of a man aged 20. 33-914 7-602 0-389 3-157) 0-118 J 54-830 Phosphate of lime, - Carbonate of lime, - Phosphate of magnesia, - Chloride of sodium, - Carbonate of soda, - Organic constituents, - Analyses of Necrotic Bone of a Middle-aqed Man. ( Von Bibra.) Stat o^W, ^ \^^ of aJdnm, - Phosphate of magnesia, - Soluble salts, .... Cartilage, - Fat, .... ' 34-383 6-636 1-182 1-919 55-880 72-63 4-03 1-93 0-61 19-58 1-22 CHAPTER VIII. EXAMINATION OF MIXED ANIMAL FLUIDS orglnt ^S^'^^J^^ variety of of such a mixture as we «^£^*? -P^ EXAMINATION OF MIXED ANIMAL FLUIDS. 225 impossible to lay down any general and consecutive scheme of experiments, which shall comprise all even of the more commonly occurring organic compounds. All that I shall attempt, therefore, in the present chapter, is to describe very briefly the methods of detecting the presence of a few of the substances which are most frequently met with in organic liquids, and which are of the most practical import- ance to the pathologist and the physician. 714. The color, consistence, and general appearance of the fluid, should be first carefully observed, as the presence of many substances, such as blood, mucus, fat, fibre, &c, may often be readily detected, even with the naked eye. Should any solid or semi-solid matter be held in suspension in the liquid, or be found as a sediment at the bottom, it should be separated, either by decantation, or by filtering through fine muslin or paper. 715. The matters thus separated from the fluid may be reserved for examination under the microscope, and also, if necessary, with other tests. The folloAving substances, among others, may in this way be readily detected :— muscular fibre and other organized tissues; epithelium (328); mucus and pus granules (329); fat and milk globules (325, 632, 633); infusoria of several kinds ; besides various amorphous and crystalline substances, many of which may at once be recognized by their peculiar form and appear- ance (315-322, &c.) 716. The liquid may first be tested with litmus and tur- meric paper, since the behavior of several of the substances about to be noticed, with reagents, will be found to vary according as the liquid containing them is acid, alkaline, or neutral. 717. The specific gravity may also be ascertained, when it can conveniently be done, as a knowledge of the density of the fluid will serve to furnish some indication of the amount of solid matter held in solution (278). Fibrin. 718. When fibrin, in the soluble state, is contained in a liquid, it gradually undergoes spontaneous coagulation, and separates from the solution, forming a more or less firm 226 ALBUMEN.—CASEIN. coagulum or jelly; and if other matters are held in sus- pension in the liquid previous to the coagulation, they are usually entangled in it,—a familiar instance of which is afforded by the coagulation of blood (473). If the liquid is decidedly alkaline to test paper, it should be neutralized with a little dilute acid, as the excess of alkali would other- wise have the effect of preventing the coagulation, since fibrin is soluble in alkaline liquids (474). The more im- portant peculiarities of fibrin have been already noticed in paragraphs 472 to 481. Albumen. 719. When albumen is suspected to be present in solu- tion, the clear liquid is to be gently boiled for a feiv minutes; if coagulation takes place, and if the ivhite pre- cipitate thus occasioned does not disappear on the addi- tion of a feiv drops of nitric acid, albumen is present. If the mixture is alkaline, it should be neutralized with nitric acid previous to boiling, since any excess of alkali would tend to retain the albumen in solution, and thus prevent the coagulation. For further particulars respecting albu- men, and its behavior with reagents, see paragraphs 133, 235, 466, &c. Casein. 720. Casein may be recognized by its forming a white curdy precipitate, when the solution containing it is neu- tralized, or very slightly supersaturated with acetic acid. It redissolves however, if the acid be added in decided ex- cess If the liquid is slightly acid to test paper, casein hardly need be looked for, since it is not soluble in acid solutions, unless the acid is present in considerable excess. It may be distinguished from albumen by not coagulating when heated; it forms, however, a thin insoluble pelHle on the surface when exposed to the air while hot-of which a familiar example is afforded in the skin of boiled milk If casein be dissolved m acetic or any other acid, it isprecipi tatedon the addition of ferrocyanide of potassium £ resembling the other modifications of protein (625) PYIN.--PUS.--MUCUS.--GELATINE. 227 Pyin. 721. This substance, which appears to be identical with the tritoxide of protein, and is consequently closely allied to the other protein compounds (472), may be recognized by its throwing down a precipitate with acetic acid, which does not redissolve in an excess of the acid. A solution of alum also causes a white precipitate, insoluble in excess; in which respect pyin differs from glutin and chondrin (725, 726). Unlike most of the protein compounds, it is not pre- cipitated by ferrocyanide of potassium. Pus. 722. When pyin has been detected in a liquid, it is not improbable that, on examination with the microscope, the peculiar pus granules (678) will also be found to be present, since pyin is one of the characteristic constituents of the fluid portion of pus (676). The principal characters of this substance, together with the modes of its detection, have been already described in paragraphs 153, 247, 674, &c. Mucus. 723. If much mucus is present, it gives to the mixture a more or less tenacious and ropy consistence, wdiich is very characteristic. Under the microscope the peculiar mucus corpuscles, as well as the fragments of epithelium which usually accompany them, will also probably be apparent (Fig. 5); and these, in conjunction with the ropiness above alluded to, are generally sufficient evidence of the existence of mucus. When present only in minute quantity, and es- pecially when mixed with pus, it is often extremely diffi- cult, if not impossible, to identify it with any degree of certainty. (See also paragraphs 31, 99, 210, 660, &c.) Gelatine; Glutin or Collin; Chondrin. 724. These substances, which are formed by boiling the cartilaginous tissues in water, closely resemble each other in many respects ; and their hot aqueous solutions all be- come gelatinous on cooling. Glue, isinglass, and the several 228 EXAMINATION OF MIXED ANIMAL FLUIDS. varieties of gelatin, met Avith in commerce, are all modifi- cations of these principles. Both glutin and chondrin are immediately precipitated, even in very dilute solutions, by a solution of tannin. They are not precipitated by ferro- cyanide of potassium ; in which respect they differ from the protein compounds. They are thrown down from their strong solutions by alcohol, in the form of a white tenacious precipitate ; and creosote causes their solutions to become turbid and gelatinous. 725. Glutin, which is obtained by boiling in water for some hours, the cartilage of bone, tendons, skin, &c, is characterized by giving with acetic acid a very slight pre- cipitate, Avhich readily redissolves in an excess of the acid. A solution of alum gives with glutin no precipitate ; or if a slight opalescence is occasioned, it disappears on the addi- tion of a further quantity of the precipitant. 726. Chondrin, on the other hand, which is formed by boiling in water any of the permanent cartilages, as those of the larynx, ribs, &c, is immediately precipitated by acetic acid, and an excess of the acid does not redissolve it. Alum, too, causes a precipitate, which, hoAvever, readily dissolves when the salt is added in excess. The solubility of gelatine in a solution of alum serves to distinguish it from pyin (721). & Blood. 727. The color which it imparts to any liquid Avith Avhich it is mixed, is usually almost sufficient evidence of the presence of blood, unless the quantity is very small. Ihe red corpuscles may also, in most cases, be detected under the microscope, more or less altered in form and size by the action of the fluid in which they float (456, 583) When blood is present, albumen also Avill be found dissolved in the liquid, unless it has been previously coagulated bV hea or otherwise ; it may be detected by the application of 235* a236n&cMC ' m the manner described in Paragraphs Biliary Matter. 728. Biliary matter, if present in any considerable quan- tity, generally communicates a more or less decided brown UREA. — FAT. 229 or yellowish color to the liquid, and also a peculiar bitter taste. It may be identified by means of Heller's and Pet- tenkofer's tests, described in paragraphs 149 and 151. If these fail to detect it in the fluid, a little of the latter may be evaporated nearly to dryness on a water-bath, and a strong aqueous solution of the residue tested as before. Urea. 729. This_ substance may be detected in organic liquids in the following manner : The portion of the organic mix- ture intended for the examination, is evaporated to dryness at a gentle heat on a water-bath, and the dry residue treated with alcohol, which will dissolve out any urea that may be present, together, probably, with some other of the matters with which it is associated. The alcoholic solution is then evaporated to dryness, and the dry extract digested with a very small quantity of moderately warm water; which will readily dissolve out the urea. The aqueous solution thus obtained is then mixed, after filtering, with pure nitric acid, in the manner described in paragraph 16, and then cooled by means of a freezing mixture; when if urea is present, delicate crystals of the nitrate (Fig. 2) will gra- dually appear. When the quantity of urea is very small, the microscope may be employed to detect any traces of the crystalline nitrate, and some other precautions must be observed, which have been described in paragraphs 181- 184, 341, &c. Fat. 730. When any considerable amount of fatty matter is present in an aqueous mixture, it may be readily detected with the naked eye, and still more delicately under the microscope, by the appearance of oily or fatty globules floating on the surface. When, however, the quantity is very small, or, owing to other circumstances, no appearance of fat is to be seen; a little of the mixture suspected to contain it, is to be evaporated nearly to dryness on a water- bath, and the residue digested Avith a little warm ether, which will readily dissolve any traces of fatty matter that may be present. On evaporating the ethereal solution on 20 230 EXAMINATION OF MIXED ANIMAL FLUIDS. a water-bath, the oil or fat will be left as a residue, and may be identified by its possessing the well-knoAvn physical characters of fatty matters (158). 731. The saponifiable fats most commonly met with in animal fluids are, oleine (C-sII75013), stearine (C142H]41017), margarine (C74H74012), and butyrine. The degree of hard- ness or of oiliness, and the temperature to which the fatty matter requires to be raised before it melts, serve to furnish some indication as to the relative amounts of the solid stearine and the oily oleine. Butyrine may generally be detected by the peculiar smell which it gradually acquires, resembling that of rancid butter. Cholesterin and Serolin. 732. If either of these surfaces are present, they will have been dissolved by the ether (730), together Avith any other fatty matters that may be contained in the liquid. They may be separated from the other fats by digestion with a solution of potash, which will dissolve out the saponi- fiable fats, and leave the cholesterin and serolin unaffected (596). These may be distinguished from each other by their different fusing-points, that of cholesterin being 278°, while that of serolin is as low as 97°. Milk. 733. The well-known physical characters of milk are generally sufficiently apparent to lead to its detection, unless largely diluted with other matters. When any doubt exists as to its presence, a drop of the liquid may be examined under the microscope for the milk globules (632); and the clear liquid, after filtration, may be tested with acetic acid for casein (623), the existence of which, in any fluid, is strong evidence of the presence of milk. The residue left by evaporating the liquid to dryness, may be tested for fat also, by digestion with warm ether, and evaporating the ethereal solution on a water-bath (730.) Sugar. _ 734. The most convenient test for the presence of sugar is that known as Trommer's which has already been fully AMMONIA. 231 described in paragraphs 122 to 124. Maumene's (125) and the fermentation test (127), may also, in many cases, be employed with advantage ; and, indeed, it is ahvays more satisfactory to confirm the results of Trommer's experiment by applying also the fermentation test; since the suboxide of copper may be sometimes produced by certain other organic substances, even when no sugar is present. If the sugar is present only in very minute quantity, it may be advisable to evaporate the liquid to dryness on a water- bath, and redissolve the soluble portion of the residue, in- cluding the sugar, in a small quantity of hot water, in the manner described in the process for detecting sugar in the blood (606). The strong aqueous solution may then be examined by Trommer's, Maumene's, and the other tests. 735. When cane sugar is suspected to be present, the solution should first be boiled for a feAv minutes with dilute sulphuric acid before the application of Trommer's test, in order to convert it into grape sugar ; since the cane variety does not otherwise produce the same characteristic results. Ammonia. 736. This substance, which is so constantly to be met with in animal fluids, as one of the results of the decom- position of nitrogenous compounds, may be readily detected even when present in very small quantities. A portion of the liquid is mixed in a test tube Avith a little caustic potash, or still better, with caustic baryta (note to 38), and warmed. The ammonia, if present, is thus disengaged, and may be detected by the smell, or, still more delicately, by holding at the mouth of the tube a glass rod moistened Avith dilute hydrochloric acid, Avhen Avhite fumes of muriate of ammonia will be distinctly visible. 737. If the ammonia is present only in minute quantity a little of the suspected liquid may be mixed with a few drops of dilute sulphuric acid, in order to fix the ammonia, and then concentrated by evaporation at a gentle heat on a water-bath; the concentrated liquid may then be super- saturated Avith potash or baryta and examined in the manner above described. 232 EXAMINATION OF MIXED ANIMAL FLUIDS. Uric (or Lithic) Acid. 738. When an organic mixture is suspected to contain uric acid, it may, if free from albuminous matter, be acidified with a few drops of hydrochloric acid, and allowed to stand a short time. The uric acid will gradually separate in the form of minute crystals (20), which may be examined under the microscope, and also tested Avith nitric acid and am- monia, in the manner described in paragraph 23. If any albuminous matter is mixed with the liquid, the latter is to be evaporated to dryness on a water-bath, and the resi- due digested with a dilute solution of caustic potash. The alkaline solution is then supersaturated with a decided excess of hydrochloric acid, which will throw down the uric acid in the form of a crystalline precipitate. If the quantity is small, a drop of the liquid may be mixed with the acid on a strip of glass, and examined for the charac- teristic crystals under the microscope (318). 739. The principal characters of uric acid, and the methods of detecting and estimating it in the urine, have been already noticed in the several chapters of Part I. P A E T V. THE DETECTION OF POISONS IN ORGANIC MIXTURES, &c. CHAPTER I. ARSENIC. 740. Although all, or nearly all, the compounds of arsenic appear to be more or less intensely poisonous, I shall here allude especially to the detection of arsenious acid (As03); since in the vast majority of cases in which arsenic is taken, whether criminally or accidentally, it is in the form of arsenious acid, or, as it is often called, oxide of arsenic, or white arsenic. The experiments which I am about to describe will serve, however, for the most part, equally well for identifying the presence of arsenic in other forms of combination than that of arsenious acid; so that, if the processes are carefully conducted, the risk of any traces of the metal escaping detection is very small. 741. When the presence of the sulphide (or sulphuret) of arsenic (AsS3) is suspected, the substance supposed to contain it may be first examined for any particles of yellow poAvder; Avhich, if present, should be mixed, when dry, with a little black flux, and heated in a small German glass tube, closed at one end ; when, if it consists of sulphide of arsenic, a crust of the metal will appear in the upper part of the tube (743). If no yellow powder can be detected, the mass in which it is suspected to be present is to be boiled with nitrohydrochloric acid, when the sulphide will become converted into arsenic acid (As05), which ^ will remain in solution, and may be detected by Reinsch's or Marsh's test (749, 745). 234 DETECTION OF AKSENIOUS ACID. SECTION I. Detection of Arsenious Acid when unmixed with other substances. 742. Place a little of the white powder in a small tube of German glass, closed at one end, and heat it gradually with the blowpipe, or in the flame of a spirit lamp. If it is arsenious acid, it will sublime, and condense in the upper part of the tube, forming a colorless crystalline sublimate, which, when examined with a good lens or microscope, will be found to consist of beautiful sparkling octohedral crystals (Fig. 72). The size and regularity of the crystals appear to depend on the slowness with which the vapor is condensed. If the surface of the glass on which the condensation takes place is quite cold, the sublimate is often amor- phous, as may be seen by holding a piece of cold glass in the fumes given ™ „i, i mL 7 off by a little arsenious acid heated on charcoal The best way to obtain large and well-defined Som^ t° r! L f6W/?inS °f ™us acid at the W ™fww be' and allow H t0 stand on a tolerably hot sand-bath for a quarter or half an hour, the lower Dart only of the tube being imbedded in the sand. If a smal stnp of flat ^ b also placed inside the tube, a portion of the acid will condense upon its surface; thus furnishW a convenient specimen for microscopic examination.8 w/l ?i f1* a li,ttle of the ^spected powder peSeJM*' t^ f°Vhis P-P-eshLldbe til of%t7y and1heaV^e mixture in a small tube of German glass before the blowpipe If arsenic is present, it will be reduced^ the metallic state, and sublime into the upper nart fa Zfi) fThingt I SMning ^tJTcSn {a Jig. (6). The tube may then be broken > u dgdin neated. 1 he reduced metal will Arsenious acid. Fig. 73. MARSH'S TEST. 235 in this Avay be reconverted into arsenious acid, crystals of Avhich will condense in the cool part of the tube (742). 744. Make a solution of some of the powder in hot water, in Avhich arsenious acid is sparingly soluble, and apply to separate portions of the solution the following tests. (See also 745 & 749.) (a) Acidify a portion of the solution with a drop or two of hydrochloric acid, and pass a current of hydrosulphuric acid gas (sulphuretted hydrogen) through the liquid, until it smells distinctly of the gas. If arsenic is present, a bright yellow precipitate of sulphide (AsS3) will be throivn doivn. (b) Add to a second portion of the neutral solution a few drops of nitrate (AgO,N05), or, still better, ammonio- nitrate (Ag0,2>NH3,N05), of silver. If arsenic is present, a canary-colored precipitate of arsenite of silver (2AgO, As03) Avill be throAvn down, which is soluble in nitric acid and also in ammonia. (c) Test a little of the neutral solution with sulphate (CuO,S03) or ammonio-sulphate (CuO,2NHvHO,SOs) of copper. This will cause, Avith arsenic, a pale green pre- cipitate of arsenite of copper (2CuO,As03), Avhich readily dissolves in an excess of ammonia, forming a rich blue solution. Marsh's Test. 745. Arrange a wide-mouthed bottle, of six or eight ounces' capacity, with tubes as shown in the annexed figure; the tube d being of hard German glass. Place in it a feAv fragments of zinc, and add a little dilute sulphuric acid, consisting of one part of the strong acid to six or eight of water. When the hydrogen has been coming off about five minutes,1 apply a light to the gas as it issues from the aperture at e, and hold over it, or rather in it, a clean porcelain crucible lid, in order to prove whether any traces of arsenic are contained in the zinc or acid employed, in which case a more or less distinct arsenical stain would be 1 This interval must be allowed to elapse, in order that the whole of the common air in the apparatus may be expelled before the light is applied; since a mixture of hydrogen and common air is highly explo- sive. 236 ARSENIC. Fig. 74. produced. If the materials are thus found to be pure, a little of the solution of the supposed arsenic is to be intro- duced through the tube b. 746. Again apply a light to the jet of gas at e, and hold in the flame a clean porcelain crucible lid. If arsenic is present, dark spots of the metal will be deposited on the surface of the porcelain, wher- ever it has been allowed to enter the flame. A few of these stains may be prepared and tested in the following manner, in order to prove whether they really consist of arsenic, and not of antimony; which latter, if present, would produce stains very similar in appearance to those of arsenic. (a) Apply the heat of a spirit lamp to one of the spots. If arsenic, it will readily volatilize, and a slight smell, re- sembling garlic, will probably be perceptible. (b) Moisten one of the spots with a drop of yellow hydro- sulphate of ammonia, containing an excess of sulphur. If it consists of arsenic it will remain undissolved for some considerable time; while, if it were antimony, it would immediately dissolve. (c) Add a drop or two of a solution of chloride of lime (CaOCI) to one of the stains. If it consists of arsenic it will immediately dissolve. 747. Hold over the flame a short wide test tube (Fig. 75), so as^ to collect the fumes of arsenious acid formed during the combustion of the arseni- uretted hydrogen. The arse- nical sublimate, which is usu- ally crystalline, may be dis- solved in hot water, and the tt. .-, . solution tested with hydro- sulphuric acid, nitrate of silver, and sulphate of cooper as described m paragraph 744, a, b, k c. (See also 749.) Fig. 75. DETECTION OF ARSENIC IN LIQUIDS. 237 The sublimate formed in the tube by antimony, under the same circumstances, would, on the contrary, prove quite insoluble in water. 748. Apply the heat of a spirit lamp to the tube at the point d (Fig. 74), and observe the formation of a dark ring of metallic arsenic inside the tube, a little in advance of the heated point. The arsenic thus deposited may be vola- tilized backwards and forwards in the tube, by applying the heat of a spirit lamp (765, a). If the tube be then dis- connected from the bottle, and the arsenic volatilized in it while filled with atmospheric air, the metal will gradually become oxidized and converted into arsenious acid, crystals of Avhich will appear in the cool part of the tube. Reinseh's Test. 749. Acidify a little of the aqueous solution of the sub- stance suspected to contain arsenic, with a few drops of pure hydrochloric acid,1 and boil in it two or three strips of clean copper foil. If arsenic is present, it will be depo- sited in the metallic state on the surface of the copper, and may be proved to be arsenic in the following manner. (a) Dry the copper strips by gentle pressure between folds of filtering paper, or by warming them on a water- bath ; when dry, place them in a small clean and dry tube of German glass, closed at one end, and apply the heat of the blowpipe. The arsenic will volatilize; and becoming oxidized while in contact with the air, arsenious acid will condense in the upper part of the tube, forming a crystal- line sublimate, which may be examined with a lens (742). (b) Dissolve the sublimate obtained in a in a little hot Avater, and apply to the solution the tests described in para- graph 744. SECTION II. Detection of Arsenic in Liquids containing Organic Matter. 750. When the liquid suspected to contain arsenic is tolerably clear, and unmixed with solid matter, it should 1 The acid employed for this purpose must be first proved to be free from all traces of arsenic, which is frequently present in small quanti- ties in the hydrochloric acid of commerce. This is readily ascertained by boiling a little of the diluted acid with strips of copper, which may then be examined for arsenic in the manner described in paragraph 749, a. 238 ARSENIC. be acidified with a little pure hydrochloric acid (the purity of which has been previously ascertained (Note to 749), and then boiled with two or three small strips of copper foil or wire gauze. If arsenic is present it will probably be deposited, in the course of a few minutes, upon the surface of the copper, and must be treated in the manner presently to be described (751). It must not, however, be considered certain that no arsenic is contained in the liquid, until after boiling the mixture for half an hour, or even longer ; when, if no stain is produced which, on examination, gives indi- cations of arsenic, it may safely be concluded that no trace of the metal is present. 751. It occasionally happens that a little fatty animal matter is deposited on the surface of the copper during the boiling. When this is the case, the copper should be boiled with a little ether or alcohol, in order to dissolve it, before being exposed to heat in the tube. 752. The copper strips must now be heated in a small clean and dry tube, closed at one end; when, if any arsenic has been deposited upon them, a crystalline sublimate of arsenious acid will appear in the upper part of the tube. If, on examination with a lens, the sublimate is found to exhibit the characteristic crystalline form and appearance of arsenious acid (742), there can scarcely be a doubt of the existence of arsenic. It is, however, always advisable, in cases of medico-legal investigation, to obtain the com- bined testimony of other experiments, in order to obviate the possibility of error. 753. For this purpose, the white sublimate is to be re- moved from the surface of the glass with a clean knife, and divided into three portions, A, B, & C. (a) Mix the portion A, which should be previously dried on a water-bath, with a little dry black flux, and heat the mixture in a clean narrow tube, closed at one end. A crust of metallic arsenic ought to be produced in the cool part of the tube (743). r (b) Dissolve the portion B in a little water acidified with hydrochloric acid, and apply Marsh's test, in the manner described in paragraphs 745-748. (c) Dissolve the portion C in hot water, and divide the solution into three parts, Avhich may be tested respectively ARSENIC IN ORGANIC MIXTURES. 239 with hydrosulphuric acid, ammonio-nitrate of silver, and ammonio-sulphate of copper, as directed in paragraph 744, a, b, & c. SECTION III. Detection of Arsenic in Organic Mixtures containing both Liquid and Solid Matters; such as the Contents of a Stomach, Vomited Matters, ct-c. 754. When the liquid and solid portions of the mixture are found capable of ready separation, either by subsidence or filtration, it is generally better to examine each of them separately. When this is not the case, see paragraph 758. 755. Examination of the liquid portion.—The clear liquid after the removal of the solid matter, either by fil- tration or otherwise, is to be acidified with a little pure hydrochloric acid, and boiled with a few strips of clean copper; which, after being dried between folds of filtering paper, are to be heated in a dry tube, and the sublimate, if any, examined in the manner described in paragraph 749. 756. Examination of the solid portion.—This should first be examined for any small lumps of arsenious acid, which, in cases of poisoning, are often to be found adhering to the coats of the stomach. These should be carefully picked out, and tested according to the directions given in paragraphs 742-744. 757. The solid or semi-solid organic matter is then to be boiled with dilute hydrochloric acid, containing about one- tenth of the strong acid, which will dissolve any arsenious acid that may be present. The acid solution is then filtered from any solid matter that may have remained undissolved, and boiled Avith copper strips, Avhich are to be dried, and examined for arsenic in the manner before described (749). 758. When the organic matter is viscid and incapable of ready separation into solid and liquid portions (754), it may be mixed Avith a little dilute hydrochloric acid, well stirred together, and boiled ; after which it is to be boiled Avith strips of copper, which may be subsequently examined for arsenic in the manner already described (749). 240 ARSENIC. SECTION IV. Detection of Arsenic in Oily or Fatty Matters. 759. When arsenic is suspected to be present in fatty or oily matters, in many of which it is to a considerable extent soluble, the fat may be boiled for a quarter of an hour with dilute hydrochloric acid, containing about one-tenth of strong acid. The arsenic is thus gradually dissolved by the acid, and the solution may be separated from the fat or oil by filtering through a paper filter previously saturated with water. The acid solution is then boiled with strips of clean copper, which are aftenvards to be dried, and examined according to the directions given in paragraph 749. SECTION V. Detection of Arsenic in the Tissues. 760. In medico-legal investigations as to the presence of arsenic, it is absolutely necessary in case none of the poison can be detected in the stomach and its contents, to examine the various tissues of the body; since the poison, when introduced into the stomach during life, becomes gradually absorbed, and diffused through the whole system, and may be found in the blood, urine, muscles, and viscera, especially the liver. It is therefore advisable to examine each of these for the poison ; and it should never be con- cluded, that because it cannot be detected in the stomach and its contents, none is to be found in other parts of the body. Should the patient, however, survive during several days after swallowing the poison, it is possible that the whole of it may be eliminated from the body ; in which case no trace of it will afterwards be detected _ 761. The portion of the body intended for examination1 is tobe cut up into thin slices, and boiled for an hour or two in dilute hydrochloric acid, consisting of one part of he strong acid to eight or ten of water. The mixture is then filtered through fine muslin, in order to separate the 'The part of the body in which the poison is most likely to be found ANTIMONY. 241 more solid matters ; and the clear liquid thus obtained is concentrated to about half its bulk, by evaporation at a gentle heat. The acid solution is then boiled with strips of clean copper foil, which are to be subsequently examined for arsenic in the manner described in paragraph 749. SECTION VI. Quantitative Determination of Arsenic. 762. The quantity of arsenic contained in any mixture, whether organic or otherwise, may be determined in the following manner : After having obtained the arsenic in a state of solution by boiling with dilute hydrochloric acid (758), and filtering if necessary, a current of hydrosulphuric acid gas (sulphuretted hydrogen) is passed through the acid liquid for an hour or two, and the solution, after being saturated with the gas, is then set aside for a short time in a moderately warm place. The whole of the arsenic is thus thrown down in the form of sulphide (AsS3), mixed, pro- bably, with a little free sulphur, and perhaps traces of other impurities. In order to separate it from them, it is digested in a solution of ammonia, to dissolve out the sulphide of arsenic, which may, after filtering, be again precipitated in a state of purity, by supersaturating the ammoniacal solu- tion Avith hydrochloric acid. The sulphide is then collected and washed on a filter, dried at a very gentle heat on a water-bath, and weighed. From the weight of the dry precipitate the amount of metallic arsenic, or of arsenious acid, may be estimated ; 100 parts of the sulphide being equivalent to 61-0 parts of metallic arsenic or 80-5 parts of arsenious acid. CHAPTER II. ANTIMONY. 763 The only form in which antimony is likely to be met with in medico-legal invesRation* is the double tar- trate of antimony and potash (KO,SbU3,Lsll4U10-f-Aq], commonly called tartar-emetic or tartanzed antimony, 242 ANTIMONY IN ORGANIC MIXTURES. which is often taken medicinally, and occasionally as a poison. It may be recognized by its solution giving with hydrosulphuric acid or hydrosulphate of ammonia, an orange-red precipitate of sulphide (SbS3); and by giving stains of metallic antimony when examined with Marsh's test (745, 765). SECTION I. Detection of Antimony in Organic Mixtures. 764. When a mixture containing organic matter, whether in the fluid or solid state (such as the contents of a stomach, vomited matters, &c), is suspected to contain antimony, it should be boiled with a mixture of dilute hydrochloric and tartaric acids, which will serve to dissolve any of the com- pounds of antimony that may be present in a solid form. The solution is then filtered, if necessary, from any inso- luble matter; and a stream of hydrosulphuric acid (sulphu- retted hydrogen) is passed through the clear solution, until the latter is saturated with the gas. The antimony, if any is present, is thus precipitated as the orange sulphide, which may be separated by filtration, and dissolved in as small a quantity as possible of hot hydrochloric acid. SbS3 + ZHCl=Sb CT34- 3HS. 765. The solution of chloride of antimony thus obtained may then be divided into three portions for testing (a) Try the first with Marsh's test, by adding it in a proper bottle (745) to a mixture of zinc and sulphuric or hydrochloric acid, and examining the stains with hydro- sulphate of ammonia and chloride of lime. By the first of these it should be immediately dissolved ; and unaffected, or nearly so, by the second (746, b and c). On applying the heat of a spirit lamp to the tube at the point d (Fig 74) a deposit of metallic antimony will be produced at the heated point. Unlike the deposit formed by arsenic under similar circumstances, it will not be found to volatilize with the heat of a spirit lamp (748). (b) The second portion of the acid solution may be mixed with five or six times its bulk of water, which shouldTuse a milkiness in the solution, owing to the formation of ?he basic oxychlonde of antimony (SbClv5SbO,). The pre -ANTIMONY IN THE TISSUES. 243 cipitate thus occasioned is soluble in a solution of tartaric acid. (c) The third portion may be mixed with about its own bulk of water, and saturated with hydrosulphuric acid gas, which should cause an orange precipitate of the sul- phide (763). If, hoAvever, the color of the precipitate pre- viously thrown doAvn by this reagent (764), was decidedly orange, and not masked by the presence of other matters, this experiment need not be performed. SECTION II. Detection of Antimony in the Tissues. 766. The portion of the body intended for examination (the liver being, if possible, selected (note to 761), is to be cut into thin slices, and digested for an hour or so in a mixture of dilute hydrochloric acid (containing one part of strong acid to about eight parts of Avater), and tartaric acid, Avhich should be kept by gently boiling. The anti- mony is in this Avay effectually brought into solution, partly as chloride, and partly in combination Avith tartaric acid. The mixture may then be filtered, and the clear solution decomposed by a stream of hydrosulphuric acid gas, which will throAv doAvn the antimony in the form of the orange sulphide (764). This is to be separated by filtration, and converted into the chloride by dissolving it in a small quantity of hot hydrochloric acid; after which the acid solution may be tested in the manner described in para- graph 765. SECTION III. Quantitative Determination of Antimony. 767. If it is required to estimate the quantity of antimony in any organic mixture, the latter is treated in the manner described in paragraph 766, first Avith hydrochloric and tar- taric acids, and then after filtration, saturated with hydro- sulphuric acid gas ; by which the antimony is precipitated as the orange-colored sulphide. This is then separated by filtration, dried at a gentle heat, and Aveighed. One hundred grains of the sulphide thus obtained is equivalent to 72-8 grains of metallic antimony, or to about two hun- dred grains of the double tartrate. 241 MERCURY. CHAPTER III. MERCURY. 768. The most common preparation of mercury, by which life has been sacrificed or endangered, is the bichloride (HgCI,), commonly called corrosive sublimate; the chloride, or calomel (HgCI), the red oxide (Hg02), and some of the other compounds, are also sometimes administered, either criminally or accidentally, with fatal effect, and may con- sequently have to be looked for by the medical jurist. In the process I am about to describe, however, any of these compounds will be brought into a state of solution; after which the mercury contained in them may readily be de- tected by the proper tests. SECTION I. Detection of Mercury in Organic Mixtures. 769. When the presence of mercury is suspected in an organic mixture, such as the contents of a stomach, the solid and liquid portions of the matter to be examined may be separated from each other, either by filtration or decan- tation, provided the separation takes place readily; or if this is not the case, the whole of the mixture may be treated with acid, and examined in the manner described in para- graphs 774-776. 770. Examination of the liquid portion.—The liquid portion may be first examined. Acidify it with a few drops of hydrochloric acid, and boil the mixture for a quarter or half an hour, with two or three strips of clean copper foil. If any mercury is present in the liquid, it will in this way be entirely separated from the solution and deposited on the surface of the copper. The latter is then removed from the acid liquid, and washed with a little dilute solution of ammonia, in order to remove from the surface any adhering oxide or subsalt of copper. The strips are then dried by gentle pressure between folds of bibulous paper, or still better, at a very moderate heat on a water-bath, and placed in a small and perfectly dry German glass tube, three or tour inches long, closed at one end. MERCURY IN ORGANIC MIXTURES. 245 771. The heat of the blowpipe is then applied to the bot- tom of the tube containing the copper strips ; when, if any mercury has been deposited upon them, it will be volatil- ized by the heat, and condensed in the cooler part of the tube, forming a delicate and dew-like ring of minute globules of metallic mercury; the real nature "of which may be at once seen with the assistance of a common lens, if not with the naked eye. 772. If, in the experiment above described (771), the ap- pearance of metallic globules is distinctly visible, it will scarcely be necessary to apply any further tests to prove the presence of mercury, since no other substance is capable of producing such a sublimate. If, however, any doubt ex- ists as to the nature of the sublimate, the following experi- ments may be made: 773. Remove the copper from the tube, and dissolve the sublimate in nitrohydrochloric acid ; by which the mercury, if present, will be converted into the soluble bichloride (HgCl2). Expel the excess of acid by evaporation at a gentle heat; and apply to an aqueous solution of the resi- due, the following tests: (a) Solution of iodide of potassium (KI) gives a brilliant red precipitate of periodide of mercury (Hgl2), Avhich is soluble in excess either of the mercurial solution or of the iodide of potassium. (b) Solution of potash gives a yelloAv precipitate of hy- drated peroxide of mercury (Hg02,3HO), which is insoluble in an excess of the precipitant. (c) A stream of hydrosulphuric acid gas (sulphuretted hydrogen), or a drop or tAvo of hydrosulphate of ammonia, form at first a white precipitate, consisting of a double compound of chloride and sulphide (2HgS,,HgCl2), which, unless the precipitant be added very sparingly, almost im- mediately becomes darker, owing to the admixture of the black sulphide (HgS2). If the precipitant be added in excess, the whole of the precipitate becomes black. (d) The dry mercurial salt when mixed with carbonate of soda, and heated in a narroAv tube before the blowpipe, yields a sublimate of minute globules of metallic mercury. 774. Examination of the solid portion.—The solid por- tion of the mixture may contain mercury in combination 21* 246 MERCURY. with certain animal matters, besides particles of calomel, oxide, or some other mercurial compound. It may first be examined for any visible fragments of these, which, if de- tected, may be picked out, and tested for mercury, by mix- ing them, when dry, with carbonate of soda, and heating the mixture in a small tube before the blowpipe; when the mercury will be sublimed into the cooler part of the tube (773 d). 775. The rest of the solid matter may now be warmed with a little nitrohydrochloric acid, which Avill convert the oxide or chloride, if present, into the bichloride, and thus insure the solution of any mercurial compound that may be contained in it. The excess of acid may then be expelled by evaporating the liquid to dryness on a water-bath ; after which the residue is to be redissolved in a small quantity of water. 776. The solution thus obtained may now be acidified with a few drops of hydrochloric acid, and boiled for a quarter or half an hour Avith twTo or three strips of clean copper foil; on the surface of which the mercury, if present, will be deposited. The copper is then removed from the liquid, washed Avith water, and a little dilute solution of ammonia (770), and when dry, heated in a small tube of German glass, closed at one end. In this manner the mercury will be volatilized, and may be seen condensed in the upper part of the tube, forming a dew of minute metallic globules. These may, if necessary, be redissolved in a little nitrohydrochloric acid, and the solution tested in the manner described in paragraph 773. SECTION II. Detection of Mercury in the Tissues. 777. When the presence of mercury is suspected in the viscera or other tissues of the body, the part intended for examination should first be cut into thin slices, and boiled for a short time with a little nitrohydrochloric acid • by which means any mercury that may be present will be converted into the bichloride, and thus brought into a state of solution. The undissolved matter is then separated by filtration or decantation, and the liquid portion evaporated LEAD. 247 to dryness on a Avater-bath, in order to expel the excess of acid. The residue is redissolved in Avater, acidified with a few drops of hydrochloric acid, and boiled with copper ; which must be subsequently washed withAvater and ammonia, and then examined for mercury, in the manner described in paragraphs 770-773. SECTION III. Quantitative Determination of Mercury. 778. The quantity of mercury present in any organic mixture may be determined by weighing the metal itself, obtained either by sublimation, or by boiling the liquid containing it, after being acidified Avith hydrochloric acid, with a solution of protochloride of tin. When protochlo- ride of tin is used as the reducing agent,1 the sediment of finely divided mercury should be washed with a little hy- drochloric acid, separated from the liquid by filtration, and dried on the filter (the weight of Avhich should have been previously ascertained), at a temperature not exceeding 150° ; in order to prevent the loss of any mercury by evapo- ration. It may then be weighed in the filter, which may be kept in a covered porcelain crucible. CHAPTER IV. LEAD. 779. Although instances of criminal poisoning with com- pounds of lead are of comparatively rare occurrence, still the accidental admission of it into the system, either in the form of the solid carbonate (Avhite lead) so extensively employed in the arts, or through the medium of water impregnated Avith it, very frequently leads to serious and even fetal results ; so that its detection is often a matter of grave importance. # # . 780. In testing for minute quantities of lead, it must be » See Introduction to Practical Chemistry, second edition, p. 108. 248 LEAD. borne in mind that several of the test solutions employed in analysis, when kept even for a few weeks in bottles of flint glass, dissolve out very perceptible traces of the metal from the glass, in which it is present in considerable quan- tity; so that, unless the experimenter is on his guard, he may be led to suppose that he has detected the metal in the liquid which he is examining, while, in fact he has himself introduced it in one of his reagents. Solutions of potash and soda, and their carbonates, are especially liable to become in this Avay impregnated with lead ; and several other saline solutions also, under peculiar circumstances, do the same, though more sloAvly, and in a less degree. On this account it is always advisable to test each of the reagents employed (previously neutralized, if strongly-acid or alkaline) with hydrosulphuric acid or hydrosulphate of ammonia (781), which will, if any traces of lead are present, giAre the liquid a more or less decided brown tint; or even cause a black precipitate, if the quantity of metal is at all considerable. SECTION I. Examination of Water suspected to be impregnated with Lead. 781. The Avater intended for examination (which should always be tested as soon as possible after being taken from the cistern or pipe in which it has been standing) is placed in a beaker or bottle of German or green glass, free from lead, the surface of which should be washed perfectly clean with distilled water. A stream of hydrosulphuric acid (sulphuretted hydrogen) gas is then transmitted through the water, until the latter smells distinctly of the gas. When lead is present, the liquid will generally assume a brown tint almost immediately, unless the quantity of lead is ex- tremely small; but before deciding that the water is pure, it should be set aside for a few hours, after being saturated with the gas, during which time the sulphur will be par- tially precipitated, owing to the decomposition of the hydro- sulphuric acid by the oxygen of the air,1 mixed, if any trace of lead is present, Avith a little sulphide (PbS), which 1 See Introduction to Practical Chemistry, second edition, p. 217. LEAD IN ORGANIC MIXTURES. 249 will give the sediment a more or less decided brown or fawn color. If, on the contrary, the water continues colorless, and the precipitated sulphur is white, or of a very pale sul- phur color, it may be concluded that no perceptible trace of lead is contained in the Avater. 782. If, however, any uncertainty exists, half a pint of the water may be evaporated to dryness, and the residue moistened with a solution of hydrosulphuric acid, or a drop of dilute hydrosulphate of ammonia ; when, if no black or even brown color is produced, the absence of lead may be considered certain. If the residue is found to become brown or black on the application of the hydrosulphuric acid or hydrosulphate, it is probably OAving to the presence of lead ; but as a similar effect may, under certain circumstances, be produced by iron and other impurities, the residue may be moistened with a little dilute nitric acid, gently Avarmed, and dissolved in as small a quantity as possible of Avater. The solution thus obtained may then be tested for lead in the manner described in paragraphs 785-787. SECTION II. Detection of Lead in Organic Mixtures. 783. If the organic matter to be examined is a mixture of solid and liquid, such as the contents of a stomach, the two portions should, if practicable, be separated by filtration through paper or muslin ; having been previously diluted, if necessary, Avith a little Avater, Avhich will cause the liquid to pass more readily through the pores of the filter. The liquid portion may be first tested; and in case none of the metal can be detected in it, the solid or semi-solid matter may be afterAvards examined (788). 784. Examination of the liquid portion.—A current of hydrosulphuric acid gas is passed through the liquid for about a quarter of an hour, by which means any lead that may be dissolved Avill be precipitated as the black sulphide. This is to be separated by filtration, and the greater part of it digested, with the aid of a gentle heat, in moderately dilute nitric acid ; a small portion being retained for exa- mination Avith the blowpipe (787). 785. When the sulphide is for the most part decomposed 250 LEAD. by the nitric acid (which may be known by the undissohred residue, consisting chiefly of sulphur, becoming nearly white), the clear solution is to be poured off the insoluble matter, and tested in the folloiving manner (786); the un- dissolved residue being also retained, in case it may be required for subsequent examination (787). The digestion in Avarm acid should not be continued longer than necessary, since the prolonged action of the nitric acid might have the effect of oxidizing the sulphur as Avell as the lead, forming sulphuric acid, which would combine with the oxide of lead, and precipitate it from the solution in the form of the in- soluble sulphate (PbO,S03). 786. The clear solution (785) is now to be evaporated to dryness on a water-bath, in order to expel the excess of nitric acid; after which the residue is to be redissolved in warm Avater, and tested in the following manner; or, if the quantity is small, the tests b, c, & d only need be applied. (a) Hydrosulphuric acid and hydrosulphate of ammonia cause a black precipitate of sulphate of lead (PbS). _ (b) Dilute sulphuric acid, or a solution of sulphate of soda, gives a white precipitate of sulphate of lead (PbO,SO ), Avhich is insoluble, or nearly so, in acids, but gradually dissolves in a solution of caustic potash. (c) The sulphate formed in b, after being washed with distilled water, is instantly blackened when moistened with Lydrosulphate of ammonia or a solution of hydrosulphuric acid owing to the formation of the black sulphide. The sulphate of lead may in this way be readily distinguished from the sulphate of baryta and strontia, which it resembles in many respects. (d) A solution of iodide of potassium (KI) throws down a bright yellow precipitate of iodide of lead (Pbl), which is so able in hot water, and, on cooling, separates from the solution m the form of brilliant crystalline scales, of great caul^th^SI- add' °r a S°1Uti°n °f cW°ride of sodium> causes it the solution is not very dilute, a Avhite crystalline precipitate of chloride of lead (PbCl), Avhich dissolveswhen the mixture is heated, and crystallizes in the form of del" cate needles as the solution cools (f) Chromate of potash (KO,Cr03) gives a rich yellow LEAD IN THE TISSUES. 251 precipitate of chromate of lead (PbO,Cr03), which is soluble in potash, and insoluble in dilute acids. (g) If any of the precipitates formed in the above experi- ments be dried, and heated on charcoal, with or without a little dried carbonate of soda, in the inner flame of the bloAvpipe,1 minute metallic beads will be obtained; which may be recognized as lead by their softness and mallea- bility. 787. If no decided indication of lead can be obtained from the nitric acid solution, the other portion of sulphide (784), and also the residue which proved insoluble in the acid (785), may be dried, mixed Avith carbonate of soda, and heated in the inner flame of the bloAvpipe; when, if any lead is present, it will be speedily reduced to the metallic state, forming minute malleable beads. 788. Examination of the solid portion.—If the examina- tion of the liquid portion should fail in proving the presence of lead, the poison may still be sought for in the solid or semisolid matters left on the filter (783), since it may exist in combination Avith animal matter, or in some other inso- luble form. The mixture is evaporated to dryness, and the dry mass, after being reduced to poAvder, is to be mixed Avitli three or four times its Aveight of black flux, and care- fully ignited for about a quarter of an hour, in a covered Berlin porcelain crucible. The lead, if present, is thus re- duced to the metallic state ; and unless the quantity is very small, will be found in the form of a round globule at the bottom of the crucible. 789. If a button of metal is thus produced, it may be proved to be lead by its Avell-knoAvn physical properties, such as softness and malleability ; or by dissohring it in dilute nitric acid, and after expelling the excess of acid by evaporation, testing the solution in the manner described above (786). 790. If, however, no globules of lead are visible, the Avhole of the incinerated matter may be boiled with dilute nitric acid; by which any lead will be dissolved, and may be detected in the solution by the tests before described (786), after filtering from the insoluble carbonaceous 1 See Introduction to Practical Chemistry, second edition, p. 35. 252 LEAD. residue, and expelling the excess of acid evaporation, as before. SECTION III. Detection of Lead in the Tissues. 791. When, in a suspected case of poisoning by lead, no trace of the metal can be detected in the contents of the stomach, &c, it is necessary, before deciding upon the absence of the poison, to examine the tissues of the stomach, intestines, and especially the liArer; since it may be often found absorbed in these tissues, even when no trace is to be met elsewhere. 792. The portion of the body intended for examination is to be cut into thin slices, and dried, after Avhich the dry residue is to be reduced to powder, mixed with three or four times its weight of black flux, and ignited for about a quarter of an hour in a covered Berlin porcelain crucible. The incinerated mass is then to be examined for any glo- bules of metal; and if none of these can be found, it may be digested Avith dilute nitric acid in the manner described in paragraph 788, and tested for lead according to the directions already given. SECTION IV. Quantitative Determination of Lead. m 793. When it is required to estimate the quantity of lead in an organic mixture, the metal must first be brought, if not already so, into a state of solution (788), and precipitated by means of a current of hydrosulphuric acid, which must be continued until the liquid is found to smell strongly of the gas. The sulphide (PbS) thus formed, is to be filtered and converted into the sulphate (PbO,S03) by boiling Avith strong nitric acid; a few drops of dilute sulphuric acid being afterwards added, in order to insure the conversion of the whole of the lead into sulphate. The sulphate of lead is then dried in a counterpoised porcelain crucible, and ignited; after which it may be weighed. From the weight of the sulphate thus obtained, that of the lead may be etti- mated, as follows : J Atomic Weight of sul- Weight of lead In kid m£ ?to„ the quantity of the «ao. obtained. mixture employed t^ys^ v------,______i \________ COPPER IN ORGANIC MIXTURES. 253 C1IAPTKR V. COPPER. 794. Like lead, copper is not often employed for the purpose of criminally destroying life ; but is not unfre- quently taken accidentally dissolved in articles of food, with serious, and sometimes fatal, results. The chief cause of such accidents is the employment of untinned copper vessels for culinary purposes ; and although such vessels, Avhen perfectly clean, may be used in the preparation of certain articles of food without risk of impregnation, still the number of alimentary substances capable of acting upon and dissolving small quantities of the metal, is so great that it is far safer to avoid the use of untinned copper vessels in all culinary operations. Acid and fatty substances especially, and liquids containing common salt and other saline matters in solution, should never be boiled in such vessels; since the quantity of copper dissolved by them is sometimes so considerable, as to impart a green or bluish color to the mixture. SECTION I. Detection of Copper in Organic Mixtures. 795. Copper may exist in such mixtures either in a state of solution, or in combination Avith certain organic or other substances, forming compounds Avhich are more or less in- soluble in Avater. On this account Avhen the mixture to be examined consists of both liquid and solid matters, it should first be warmed Avith a little hydrochloric or acetic acid, by Avhich means the copper will be brought into solution. The solution may then be filtered from the insoluble portion, which latter should be retained, in case it may be required for subsequent examination (798). 796. The clear liquid, slightly acidified with a few drops of hydrochloric acid, is noAv to be tested for copper, by placing in it a piece of clean iron, free from rust, such as a needle, or knife-blade. If copper is present in the liquid, it Avill in a short time be deposited in the metallic state on 254 COPPER. the surface of the iron, giving it all the appearance of copper; while the iron is at the same time dissolved in atomic proportion. The color of the freshly deposited copper is so peculiar and characteristic, that it can hardly be mistaken after being once seen ; so that this experiment is generally sufficient of itself to prove the presence of the metal. If, however, any doubt exists as to its presence, the folloAving tests may be applied, either to a portion of the liquid from which the copper has not been removed by means of the iron, or to a solution of the precipitated copper scraped off the iron, in dilute nitric acid. 797. (a) Hydrosulphuric acid and hydrosulphate of am- monia throw doAvn a black precipitate of sulphide of copper (CuS). (b) Ammonia, Avhen added in small quantity, throws down a pale blue precipitate, which, if the ammonia be added in excess, redissolves, forming a beautiful blue solu- tion. (c) Potash throAvs down in the cold solution a pale blue precipitate of hydrated oxide (CuOHO); Avhich, on boil- ing the mixture, becomes black, owing to the formation of the anhydrous oxide (CuO). The potash must here be added slightly in excess, as otherwise the precipitate Avould consist of a basic salt, Avhich Avould not become black Avhen boiled. (d) Ferrocyanide of potassium causes, even in very dilute acid or neutral solutions, a mahogany-colored precipitate of ferrocyanide of copper (Cu2,FeCy3), which is insoluble in dilute acids. 798. In case no copper can be detected in the liquid portion, it is advisable, before deciding that the metal is altogether absent, to examine the residue which proved insoluble in the dilute acid (795). For this purpose, it is to be evaporated to dryness, and ignited in a covered Berlin porcelain crucible. The incinerated residue is then warmed with a little dilute nitric acid, which will dissolve any traces of copper that may be present. The acid solution is evaporated nearly to dryness, in order to expel most of the excess of acid, and filtered; after which the solution may be tested with a piece of clean iron (796), and also, if necessary, with the other reagent* above enumerated (797). QUANTITATIVE DETERMINATION OE COPPER. 255 SECTION II. Detection of Copper in the Tissues. 799. Like the other metallic poisons, copper is readily absorbed by the tissues, where it may frequently be found in cases Avhere no trace can be detected in the contents of the stomach and intestines. On this account, it is neces- sary, before concluding that no copper can be found, to examine the liver and other viscera, wdiich may be done in the following manner. 800. The part intended for examination is to be cut into thin slices, and Avarmed Avith dilute nitric acid (consisting of one part of the strong acid and five or six parts of water), which Avill dissolve out any copper that may be present. The acid solution, after filtering, is evaporated nearly to dryness ; after Avhich it may be tested with a piece of clean iron (796), and if necessary, Avith the other reagents men- tioned in paragraph 797. SECTION III. Quantitative Determination of Copper. 801. The quantity of copper present in any solution, or organic mixture, may be ascertained by saturating the liquid (after boiling Avith dilute acid, and filtering, if any solid or semi-solid matter is left undissolved) Avith hydro- sulphuric acid gas, Avhich will throw doAvn the AAThole of the copper as sulphide. The precipitate is to be dissohred in hot nitric acid, and the copper throAvn doAvn as oxide, by supersaturating the hot solution of the nitrate AA'ith potash. The black oxide thus precipitated is to be washed Avith a large quantity of hot Avater, filtered, dried, ignited, and Aveighed. From the weight of the oxide, that of the metallic copper may be calculated as folloAVS : Ate. wt. of oxide Ate. wt. of Wt. of oxide Wt. of copper in the quantity of copper. copper. obtained. of mixture employed. 40 : 32 :: a : x 256 ZINC. CHAPTER VI. ZINC. Detection of Zinc in Organic Mixtures and in the Tissues. 802. Zinc has occasionally to be looked for in organic mixtures and in the tissues, the sulphate being often ad- ministered as an antidote in cases of poisoning. It may be detected by boiling the suspected matters in a finely diA'ided state, Avith a little dilute hydrochloric acid, and filtering if necessary, from any insoluble residue. The clear solution thus obtained may then be supersaturated with ammonia, Avhich will, at first, throw doAvn a Avhite gelatinous precipi- tate of hydrated oxide, which readily redissolves when the ammonia is added in excess. The mixture is then filtered ; after which the clear ammoniacal solution may be tested with a current of hydrosulphuric acid gas (sulphuretted hydrogen), which, if zinc is present, Avill throAV down a Avhite precipitate of sulphide (ZnS). The sulphide thus formed may be separated from the liquid by filtration, and dissolved in a little hydrochloric acid or aqua regia ; the excess of acid employed being after wards expelled by eva- porating the solution to dryness. 803. A portion of the dry residue may be moistened with a solution of nitrate of cobalt, and heated on platinum wire before the blowpipe ; Avhen, if any zinc is present, the fused mass will exhibit a more or less decided green color. 804. The remaining portion of the dry residue may then be dissolved in water, and the solution filtered from any sulphur that may be present; after Avhich it may be tested for zinc as folloAvs : (a) Hydrosulphate of ammonia gives a Avhite precipitate of sulphide of zinc. (b) Ammonia gives a white gelatinous precipitate of hydrated oxide, readily soluble in an excess of the preci- pitant. (c) Ferrocyanide of potassium causes a white precipitate of ferrocyanide of zinc. IODINE. 257 CHAPTER VII. IODINE. SECTION I. Detection of I, ncombincd Iodine in Organic Mixtures, &<\ 805. When iodine is present in an organic mixture, it may be detected in the following manner; Avhich will also serve to identify it after having been absorbed by the tissues of the stomach, liver, or other organ, such organ having been first carefully cut into thin slices, and mace- rated Avith a little water. The characteristic smell of iodine is generally perceptible in liquids containing it; and it usually imparts to organic mixtures a yelloAV or greenish color. 806. The mixture may first be examined for any particles of iodine that may be present in the solid state ; Avhich, if found, may be at once identified as such, by the beautiful violet-colored vapor Avhich they form Avhen gently heated in a small glass tube. 807. If no solid iodine can be found, the liquid may be tested with a solution of starch; or a strip of cotton or paper, impregnated with starch, may be moistened Avith it. If iodine is present in the solution, it will immediately strike a more or less decided purple color, the intensity of the tint varying from almost black to a pale shade of pink or lilac, according to the quantity of iodine dissolved in the liquid. 808. Should the quantity of iodine in the solution be so minute as to fail in producing a sufficiently decided result, the mixture may be evaporated nearly to dryness on a water-bath, and'the residue digested with ether; which will dissolve and carry with it to the surface, any iodide that may be present. The ethereal solution may then be evaporated at a gentle heat, and the residue examined for iodine by heating it gently in a small glass tube (806); or by dissolving it in water, and testing with starch (807). J 22* 258 SULPHURIC ACID. SECTION II. Detection of Iodide of Potassium (Kl) in Organic Mixtures, dr. 809. If the organic mixture, or the liquid in Avhich the sliced tissues have been macerated (805), is colored to any considerable extent, it is advisable, before applying the tests, to remove the coloring matter by boiling Avith fresh animal charcoal; since the color might interfere with, or mask, some of the results. 810. A little of the solution may then be mixed with a drop or two of nitrohydrochloric acid or a solution of chlorine, which, if any iodide is present, will decompose it, and set free the iodine.1 The iodine thus liberated may then be detected by means of starch, in the manner already described (807). 811. The liquid suspected to contain iodide of potassium, may also be tested with solutions of acetate of lead and bichloride of mercury. With the first it will, if present, produce a bright yellow precipitate of iodide of lead; and with the second, a brilliant red precipitate of periodide of mercury. CHAPTER VIII. SULPHURIC ACID (HO,S03). SECTION I. Detection of Sulphuric Acid in Organic Matters. 812. Sulphuric acid may be readily detected, even when mixed with a large quantity of foreign matter. Should the substance to be examined be viscid or semisolid, it may be diluted with a little water, and boiled ; after which, if any solid matter remains in suspension, it may be filtered through muslin or paper. 1 See Introduction to Practical Chemistry, second edition p. 12G. sulphuric acid in organic mixtures. 259 813. If the liquid contains free sulphuric acid, it will of course strongly redden blue litmus paper. 814. Mix the liquid to be tested, with a little nitric acid, and add a solution of chloride of barium or nitrate of baryta. If sulphuric acid is present, a copious Avhite pre- cipitate of sulphate of baryta will be produced, which will not dissolve on boiling the acidified mixture, nor yet on diluting it with a considerable quantity of water.1 815. If no precipitate is occasioned by the baryta salt, it may be concluded that no sulphuric acid is present; but as certain other acids besides, sulphuric might, if present, cause a similar precipitate, as, for instance, the sulphurous, iodic, or selenic, it is advisable to prove that the precipitate is really the sulphate, before finally deciding that sulphuric acid is present. The probability of any of the other acids which I have alluded to being contained in the liquid is, indeed, very small; but in all cases of medico-legal inquiry, no means should be neglected whereby the risk of error can be removed or diminished. 816. In order to prove Avhether the precipitate caused by the baryta salt is indeed the sulphate, it should be sepa- rated from the solution by filtration, dried, and mixed with four or five times its weight of pounded charcoal. The mixture is placed in a small tube closed at one end, and heated; Avhen the sulphate will be converted into sulphide of barium (BaS), OAving to the charcoal combining with the oxygen both of the baryta and the sulphuric acid. The ignited mixture, after cooling, is to be moistened with a few drops of dilute hydrochloric acid, Avhich will disengage fumes of hydrosulphuric acid (sulphuretted hydrogen), readily detected by their offensive smell, and also by black- ening a strip of paper moistened with a solution of lead, held at the open end of the tube. 817. Since traces of sulphuric acid may be contained in the nitric acid used in acidifying the mixture (814), a little of the nitric acid employed, should be diluted with three or four times its bulk of Avater, and tested Avith chloride of barium. 818. It is possible, also, that the substance under exami- nation may contain some soluble sulphates in solution, as ' Ibid. p. 120. 260 sulphuric acid. sulphate of magnesia, sulphate of zinc, &c, which Avould cause the precipitation of sulphate of baryta with chloride of barium, even when no free sulphuric acid is present. To remove this source of error, a little of the suspected fluid may be evaporated nearly to dryness at a gentle heat, when any saline matter that may be present will crystallize out; while the free sulphuric acid will continue liquid, and may be identified by the proper tests. Or a little of the fluid, of knoAvn Aveight, may be evaporated and gently ignited, Avhereby the free acid will be expelled, Avhile the sulphates will remain behind. Then, by estimating the amount of sul- phuric acid in the saline residue (822), and ascertaining also by experiment the quantity of sulphuric acid in an equal Aveight of the fluid previous to evaporation, we can learn how much of the acid was in combination, and how much free; that in the ignited portion being derived from the sulphates, and the difference between the tAvo repre- senting the free acid Avhich Avas expelled during ignition. 819. It is not often, hoAvever, that any serious uncer- tainty can exist as to whether the sulphuric acid found mixed Avith organic matter Avas or wTas not uncombined, especially in cases of suspected poisoning ; since the corro- sive effects of the acid upon the parts Avith Avhich it has been in contact, or other corroborative circumstances, Avill generally of themselves furnish evidence sufficiently con- clusive. SECTION II. Detection of Sulphuric Acid in Stains on Clothing. 820. The stains formed by sulphuric acid on articles of clothing are usually moist to the touch, and most commonly of a brown or red color, varying, however, with the nature of the material and of the dye. The acid may be detected in them by boiling the stained part with water, and testing the solution ivith litmus paper (813), and with chloride of barium and nitrate of baryta (814). SECTION III. Detection of "Sulphate of Indigo" in Organic Mixtures, &c. 821. The solution of indigo in sulphuric acid, commonly called sulphate of indigo, which is occasionally either em- II Y D R 0 C II L 0 111 C A C I D. 261 ployed as a poison, or criminally thrown upon the person, may be detected in the same manner as the simple acid. It has a deep blue color, which may be destroyed by boil- ing with nitric acid previous to the application of the tests ; after which the sulphuric acid may be identified either in organic mixtures or on articles of clothing, by the experi- ments described in paragraphs 814-818. SECTION IV. Quantitative Determination of Sulphuric Acid. 822. The acid may, for this purpose, be precipitated in the form of sulphate of baryta, in the manner described in paragraph 814. The precipitate is then washed on a filter, with boiling distilled water, dried, ignited, and weighed ; when the quantity of acid may be calculated as follows : Ate. wt. of Ate. wt. of Wt. of acid in the sulphate aqueous sul- AVt. of sulphate of quantity of mix- of baryta. phurie acid. baryta obtained. ture employed. 117 : 49 CHAPTER IX. HYDROCHLORIC ACID (HCl). SECTION I. Detection of Hydrochloric Acid in Organic Mixtures. 823. When free hydrochloric acid is present in an organic /mixture, it may be detected in the following manner. If solid or semisolid matter is mixed with the liquid, it should be first boiled, and filtered through muslin; and when the mixture is thick and viscid, a little water should be mixed with it before boiling. The liquid is then treated with a tolerably strong infusion of galls, as long as it causes a precipitate, in order to throw doAvn most of the dissolved animal matter, Avhich Avould otherwise tend to prevent the acid distilling over. The precipitate is then separated from 262 HYDROCHLORIC ACID. the clear liquid, either by again filtering through muslin, or by decantation. 824. A few drops of the solution, thus purified from the greater portion of the organic matter, may now be tested with nitrate of silver. If this causes a white precipitate, soluble in ammonia, and insoluble in nitric acid, the liquid will have to be further examined (825); since the precipi- tate may be OAving to the presence of chloride of sodium or some other soluble chloride. But if no such precipitate is occasioned by the silver salt, the absence of hydrochloric acid may be relied on; unless, indeed, the solution is am- moniacal, in which case it should first be neutralized or slightly supersaturated Avith nitric acid. 825. In order to prove Avhether the precipitate caused by nitrate of silver (824) is OAving to the presence of free hy- drochloric acid, or of some soluble chloride, the liquid is to be distilled to dryness in a retort. The neck of the re- tort is to be attached by means of a perforated cork to a quilled receiver, the quill of which should be alloAved to dip just beloAV the surface of a little pure Avater placed in the flask or bottle intended for its reception.1 The bulb of the retort is to be heated in a chloride of calcium bath, the heat of which may be raised, toAvards the end of the distillation, to about 230°. 826. When the wdiole of the liquid has distilled over, the contents of the receiver are to be examined, first with blue litmus paper, which, if any free acid is present, will become reddened; and also with nitrate of silver, Avhich will give a copious Avhite precipitate of chloride, soluble in ammonia, and insoluble in nitric acid, in case any free hydrochloric acid Avas present in the mixture, since such acid Avould distil over Avith the Avater. 827. A little of the distilled liquid may also be mixed with a few drops of pure nitric acid, and boiled for a few minutes with a small fragment of gold leaf. If the latter dissolves, it is an additional proof that the acid is hydro- chloric.3 828. In examining the contents of a stomach, it must be borne in mind that minute quantities of free hydrochloric 1 See Introduction to Practical Chemistry, second edition, p. 27. NITRIC ACID IN ORGANIC MIXTURES. 263 acid are probably ahvays present as one of the normal con- stituents of the gastric juice ; so that the distilled liquid may ahvays be expected to contain some traces of it. The amount of the acid derived from this source is, hoAvever, so small, that it may readily be distinguished from the comparatively large quantity usually to be found when the acid has been SAvallowed. SECTION II. Quantitative Determination of Hydrochloric Acid. 829. The chloride of silver (AgCl) obtained by adding nitrate of silver to the distilled acid liquid (826), is to be washed on a filter, dried, and heated to dull redness in a counterpoised porcelain crucible, until it begins to fuse. From the weight of the chloride thus obtained, that of the hydrochloric acid present in the mixture may be calculated as folloAvs: Ate. weight At t f h d w of ch]orid Wt. of hydrochloric acid of chloride chloric acid. obtained. in the quantity of of silver. mixture employed. chloric acid. obtained. 144 : 37 CHAPTER X. NITRIC ACID (NOr,). SECTION I. Detection of Nitric Acid in Organic Mixtures. 830. If any solid, or semisolid organic matter is present in the mixture, it should be separated by filtering through muslin, having first boiled it, in order to effect the separa- tion of the greater part of the acid present, from the solid matters Avhich may be more or less impregnated with it. Should the liquid be thick and viscid, it may be first di- luted Avith a little Avater. 831. If free nitric acid is present in any considerable quantity in the liquid, it will probably be recognized by its 264 NITRIC ACID. peculiar smell; and the characteristic yelloiv stain of the tissues with Avhich it has been in contact, is in most cases perceptible. The Avant of smell, hoAvever, is no proof of the absence of the acid; Avhich may still be present in considerable quantity, either diluted with a comparatively large amount of liquid, or even more or less completely neutralized by magnesia, or some other alkaline substance that may have been administered as an antidote. In the latter case, the liquid may be neutral, or nearly so, to test paper. 832. In order to detect nitric acid, the liquid, after filtra- tion (830), may, if acid, be neutralized Avith carbonate of potash, and evaporated to dryness at a gentle heat. The nitric acid will thus be obtained in combination Avith potash, forming nitrate of potash, Avhich will be deposited in needle-shaped crystals Avhen most of the Avater is expelled; unless, indeed, the crystallization is prevented by the ad- mixture of much animal or other matters. 833. The greater part of the saline residue thus obtained, is to be dissolved in as small a quantity of water as pos- sible, and the solution placed in four test tubes, for the fol- lowing experiments : (a) The first portion is mixed in a small test tube, with a few drops of strong sulphuric acid; after which a clean strip or two of copper, or a little roll of copper Avire, is dropped in, and, if necessary, a gentle heat applied. If nitric acid is present, orange fumes of nitrous acid will be given off, the smell of which may generally be recognized, even Avhen in too small quantity to be apparent to the eye. (&)_ To the second portion add a few drops of hydro- chloric acid, and put a small fragment or tAvo of gold leaf into the mixture. If nitric acid is present, the gold leaf will be partially or wholly dissolved; and the presence of gold m the solution may be proved by protochloride of tin causing with it a purple precipitate. ' (e?) The third portion is to be acidified with a few drops of strong sulphuric acid, and as soon as the mixture is cool a small crystal of protosulphate of iron is dropped in ; when, if nitric acid is present, the liquid round the crystal will assume a brown color, which disappears on boilin^ the mixture. ° OXALIC ACID IN ORGANIC MIXTURES. 265 (d) Mix the remaining portion of the solution with sul- phuric acid, and add a drop of dilute sulphate of indigo, sufficient to give the liquid a pale blue color. If nitric acid is present, the color of the indigo will disappear, especially on warming the mixture. SECTION II. Detection of Nitric Acid in Stains on Clothing. 834. Stains occasioned by the action of nitric acid on woollen cloth are usually of a brown or yellowish color, and, unlike those caused by sulphuric acid (820), become in a short time dry and extremely rotten. If recent, the acid may generally be detected in them by boiling the stained part with a little water, neutralizing with potash, and applying the tests mentioned in paragraph 833 ; but if any considerable time has elapsed since the production of the stain, it is probable that all traces of the acid will have disappeared, partly by evaporation, and partly by decomposition occasioned by contact with the organic matter. CHAPTER XL OXALIC ACID (HO,C2Oz). SECTION I. Detection of Oxalic Acid in Organic Mixtures. 835. Before proceeding to apply the several tests for oxalic acid in the contents of a stomach, vomited matters, or other mixtures containing organic matter, it is advisable first to separate the latter, since its presence might interfere Avith the action of some of the reagents. If lime or mag- nesia has been used as an antidote, the oxalic acid, if pre- sent, will be either wholly or in part in the form of an in- soluble oxalate; so that, in that case, it is necessary to boil 266 OXALIC ACID. the sediment with a solution of carbonate of potash, whereby the acid will be brought into solution as oxalate of potash (KO,C203); an insoluble carbonate of the earth being at the same time formed. CaO,C2Os+.£'0,C0i=.fi'0,C20s+CaO,CO2. 836. The suspected mixture is first boiled, to insure the solution of the Avhole of the acid contained in it, and filtered, if necessary, from any solid residue. A solution of acetate of lead is then added as long as it causes any precipitate, Avhich will throw down the oxalic acid in the form of the insoluble oxalate of lead (PbO,C203), together Avith the greater part of the soluble organic matter. The precipitate thus formed is digested for an hour or two in dilute hydro- sulphate of ammonia, and the mixture then evaporated to dryness on a Avater-bath. The lead is in this Avay sepa- rated, in the form of the insoluble black sulphide, from the acid; which, in combination Avith the ammonia (oxalate of ammonia), may be dissolved out with water, leaA'ing the sulphide undissolved, together with the greater part of the organic matter. 837. The solution thus obtained is then filtered, and ex- amined in the following manner for oxalic acid: (a) A solution of sulphate of lime, or a very dilute solu- tion of chloride of calcium, added to a portion of the solu- tion, gives, if any oxalic acid is present, an immediate AA7hite precipitate of oxalate of lime (CaO,C203+2Aq), which readily dissolves in dilute nitric or hydrochloric acid, but is insoluble in acetic or tartaric acids. (b) If the oxalate of lime formed in a, be gently ignited on platinum foil, it will be converted into carbonate, Avith little or no blackening. The carbonate of lime thus pro- duced will be found to effervesce when treated with dilute hydrochloric acid, and if a little of it be strongly ignited for a short time, it will be still further decomposed, and the carbonic acid expelled; after which the residue of caustic lime will, when placed on a piece of moistened turmeric paper, change the yellow color to brown. < ( i a^61 4 3 ^?)) together with any excess of acetate ot lead that may have been employed. The mixture is warmed (not boiled, since by boilfngf some of thTmed fiSered? ° deCOmPOSed) and when again cold, is OPIUM IN ORGANIC MIXTURES. 273 856. The clear solution may first be examined for mor- phia ; reserving the precipitate for subsequent examination (862). 857. A current of hydrosulphuric acid (sulphuretted hydrogen) is passed through the solution, until the latter smells distinctly of the gas, in order to decompose the excess of acetate of lead. The precipitated sulphide of lead is separated by filtration from the solution; which latter, after boiling, and if necessary concentrated by evaporation, is to be examined for morphia by means of the following tests: 858. Place a drop or two of the concentrated solution on a strip of glass, and add a drop of ammonia. The morphia will be precipitated in the form of minute needle-shaped crystals, which may be examined under the microscope. 859. Another small portion of the solution is mixed with a solution of iodic acid (I05) ; if morphia is present, the iodic acid will be deoxidized, and the reduced iodine will give the liquid a brown or yellowish tint. If now a little solution of starch be added, it will cause a purple precipi- tate of iodide of starch. 860. Nitric acid forms with tolerably strong solutions of morphia, an orange-yellow colored compound, which becomes lighter in color when boiled. 861. A solution of perchloride of iron causes in neutral solutions containing morphia, a bluish, inky-colored pre- cipitate, somewhat similar to that caused in an infusion of galls. If the mixture be treated with nitric acid, the blue color disappears, and the orange-yellow compound is formed (860). 862. The precipitate, supposed to contain meconate of lead (856), is now to be mixed AvithAvater in a beaker glass; and Avhile suspended in the liquid, treated with a current of hydrosulphuric acid, the mixture being stirred occasionally. The meconate of lead is thus decomposed; the black sul- phide of lead being precipitated, while the meconic acid, if present, remains in solution. The mixture is filtered to separate the sulphide of lead, and the clear liquid is gently warmed (not boiled (855)), in order to expel the excess of hydrosulphuric acid; and, if necessary, concentrated by 274 OPIUM. evaporation on a water-bath. The meconic acid, if present in sufficient quantity, may then be detected by the follow- ing tests : 863. A solution of perchloride of iron gives the liquid, in case meconic acid is present, a bright red color, owing to the formation of meconate of iron. ^ The color closely resembles that caused in solutions of iron by the sulpho- cyanides, from which it may be distinguished by not being decolorized by a solution of bichloride of mercury (850). It is, however, destroyed by boiling nitric acid, chloride of tin, and the caustic alkalies. 864. Solutions of acetate of lead, chloride of barium, and nitrate of silver, produce white precipitates of meconates, which are all soluble in an excess of nitric acid. 865. Ammoniosulphate of copper throws down a green precipitate of meconate of copper, which is soluble in nitric and hydrochloric acids. EXAMINATION OF ORGANIC MIXTURES. 275 CHAPTER XIV. METHOD OF EXAMINING AN ORGANIC MIXTURE, SUSPECTED TO CONTAIN SOME MINERAL POISON, THE NATURE OF WHICH IS UNKNOAVN—VIZ., ARSENIC, ANTIMONY, MER- CURY, LEAD, OR COPPER. 866. When an organic mixture is suspected to contain one of the above-mentioned mineral poisons, it may be examined in the folloAving manner. If the matter to be examined is solid, it should first be cut into thin sliees, and any lumps of solid or semi-solid matter that may be present should be crushed and disintegrated. About three-fourths of the mixture may then be treated with hydrochloric acid, as already described in the case of arsenic (757, &c.), and gently boiled ; the remaining fourth part being retained, in case it may be required for further examination. If any- thing remains undissolved after the digestion Avith acid, it may be separated by filtering through muslin, and retained for subsequent testing, in case the examination of the liquid portion should prove unsuccessful (871). The greater part of the excess of hydrochloric acid may then be expelled by evaporation on a water-bath ; after Avhich it may be tested in the following manner: 867. A little of the solution may first be tried with Marsh's test, in the manner described in paragraphs 745 -748, Avhereby any arsenic or antimony that may be present will readily be detected. (Confirm, for arsenic, 749, 742-744; for antimony, 764, 765.) 868. Try another portion of the solution for mercury with Rcinsch's test, in the manner described in paragraphs 770, &c. (Confirm 773.) 869. Another portion of the clear liquid may be tested with a drop or tAvo of dilute sulphuric acid, or a solution of sulphate of soda. If any lead is present, it will cause a white precipitate ; which, after being washed, is turned black when moistened with hydrosulphate of ammonia (786 b and c). (Confirm, 780, d, e,f.) 276 examination of organic mixtures. 870. If copper is present in the solution, it may be de- tected by immersing a needle or other piece of clean iron, which will in that case become covered Avith a coating of metallic copper (796); or by adding a slight excess of am- monia, Avhich will cause the liquid to assume a more or less intense blue color (797 b). (Confirm, 797, c and d.) 871. In case no poison can be detected in the solution, the solid portion which was separated by filtration may be boiled with tolerably strong nitric acid, in order to insure the solution of any traces of the metals that may be con- tained in it. The acid mixture is then diluted with a little water, filtered if necessary, and deprived of the greater part of the excess of acid by evaporation on a water-bath; after which it may be tested for the several metals in the manner above described (867, &c). APPENDIX. WEIGHTS AND MEASURES. Troy or Apothecaries'1 Weight. Pound. Ounces. Drachms. Scruples. Grains. French Orammes 1 = 12 = 96 = 288 = 5760 = 372-96 1=8 = 24 = 4S0 = 31-08 ' 1 = 3 = 60 = 3-885 1 == 20 1 = 1-295 0-0647 Avoirdupois Weight. Pound. Ounces. Drachms. Grains. French Grammes 1 = 16 1 = 256 = 16 1 = 7000 437-5 27-343 = 45IV25 = 2S-328 = 1-77 Imperial Measure. Gallon. Pints. Fluid Ounces. Fluid Drachms. Minims. 1 8 = 160 = 1280 = 76,800 1 = 20 = 160 = 9,600 1 = 8 = '480 1 = 60 Weight of Water at 62°, contained in the Imperial Gallon, dr. Imperial Gallon " Pint . " Fluid Ounce " Fluid Drachm " Minim Grains. 70,000 8,750 437-5 54-7 0-91 24 278 APPENDIX. Cubic Inches contained in the Imperial Gallon, &c. 1 Imperial Gallon 1 " Pint . 1 " Fluid Ounce 1 " Fluid Drachm 1 " Minim Cuhic Inches. 277-273 34-659 1-732 0-2166 0-0036 FRENCH WEIGHTS AND MEASURES. Measures of Length. English Inches. Millimetre = •03937 Centimetre = •39371 Decimetre = 3-93710 Metre = 39-37100 Mil. Fur. Yds. Feet. In. Decametre = 393-71000 = 0 0 10 2 9-7 Hecatometre = 3937-10000 = 0 0 109 1 1 Kilometre = 39371-00000 = 0 4 213 1 10-2 Myriometre = 393710-00000 = 6 1 156 0 6 Measures of Capacity. Cubic Inches. Millilitre = -06102 = Centilitre = -61028 = Decilitre = 6-10280 = Litre = 61-02800 = Decalitre = 610-28000 = Hecatolitre = 6102-80000 = Kilolitre = 61028-00000 = 220 Myriolitre = 610280-00000 = 2200 English Imperial Measure. Gal. Pints. F. oz. F. drms. Min. 0 0 0 0 16-3 0 0 0 2 42 0 0 3 3 2 0 1 15 1 43 2 1 12 1 16 22 2 1 4 48 0 12 7 13 24 48 Measures of Weight. Milligramme Centigramme , Decigramme Gramme Decagramme Hecatogramme Kilogramme Myriogramme English Grains. •0154 •1544 1-5444 15-4440 154-4402 1544-4023 15444-0234 154440-2344 Avoirdupois. Poun. Oun. Dram. 0 0 565 0 3 8-5 2 3 5 22 1 2 INDEX. A, Acid, arsenious, ...... detection of, in organic mixtures, &c. carbonic, estimation of, . hippuric, ...... hydrochloric, detection of, in organic mixtures, &c. quantitative determination of, . hydrocyanic, detection of, in organic mixtures, &c., quantitative determination of, . lactic, ..... Iithic, ...... meconic, ..... nitric, detection of, in organic mixtures, &.c, oxalic, . . . . . - quantitative determination of, . prussic, . . . . sulphuric, detection of in inorganic mixtures, &c. quantitative determination of, uric, ...... in the blood, .... xanthoproteic, ..... Adulterations of milk, .... Albumen, ...... in the blood, in urine, estimation of, . tests for, ..... Albuminous urine, ..... Alcohol extract, ..... Alkaline salts of the urine, .... Ammonia, detected in organic mixtures, Ammoniacal salts of the urine, . . Analysis, quantitative, of albuminous urine, of diabetic urine, Animal extract, . . . . ■ Animalcules in the blood, .... Anaemia, blood in, . Antimony, detection of, in organic mixtures, the tissues, . quantitative determination of, Apothecaries' weight, .... 66, PAGE . 233 237 . 221 32 . 261 263 . 268 271 . 198 30, 54, 85 . 271 263 . 265 267 . 268 258 . 262 30, 54, 85 157, 189 145 . 206 96, 153, 226 . 186 126 66, 96, 154 . 66, 96 . 35 36 . 231 35 . 126 120 . 34 195 . 184 . 241, 274 . 243 243 . 277 280 INDEX. Arsenic, detection of, in organic mixtures, oily or fatty matters, the tissues, . Marsh's test for, . . ^ reduction test for, Reinsch's test for, quantitative determination of, Arsenious acid, .... Ass, milk of, . Avoirdupois weight, B. Becquerel, his analysis of urine, and Vernois, their analysis of milk, and Rodier, their analysis of blood, Berzelius. his analysis of urine, his analysis of bone, Bile, tests for, .... Biliary calculi, ..... Biliary matter in the blood, detected in organic mixtures, urine, .... Blood,...... corpuscles, .... morbid, ..... containing an excess of water., or deficiency of corpuscles, albumen, fibrin, saline matter of fat, of urea, of uric acid, sugar, biliary matter, pus, animalcules, . in milk, detected, in organic mixtures, . quantitative analysis of, Dumas' analysis of, stains of, identified, Blood, Simon's analysis of, Becquerel and Rodier's analysis of, Lecanu's analysis of, specific gravity of, . in the urine, Bone, quantitative analysis of, morbid, Bright's disease, blood in, Buffy coat, . Calculi, biliary, cystine, C. 143 139 INDEX. 281 Calculi, fusible, . hempseed, .... incombustible, . mulberry, .... oxalate of lime, .... phosphate of lime, qualitative examination of, triple phosphate of, . urate of ammonia, urate of lime, .... uric acid, ..... urinary, .... Calomel, detection of, in organic mixtures, &c, Carbonic acid, estimation of, . Cartilage, ...... Casein, ...... Casts, fibrinous, ..... Chalkstones, ..... Chevallier and Henri, their analysis of milk, Cholera, blood in, . ... Cholesterin, ...... in the blood, Chondrin, ...... Chylous urine, ..... Chlorosis, blood in, .... Clemm, his analysis of milk, . Collin,...... Colostrum, ..... Combustible calculi, examination of, Concretions, gouty, .... Copper, detection of, in organic mixtures, &c, . quantitative determination of, Corpuscles, excess or deficiency of, in the blood, Corrosive sublimate, detection of, in organic mixtures, &c. Cow, milk of, ..... Creatine, ..... Creatinine, ...... Cystine calculi, ..... tests for, ..... D. Deposits, urinary, examination of, microscopic examination of, Diabetes, blood in, . Diabetic urine, . ... quantitative analysis of, Dumas, his analysis of blood, 143 136 137 141 137 137 134 140 135 133 138 132 131 244 221 216 228 197 226 68 144 201 186 189 230 188 227 73 100 184 201 227 199 205 140 144 253 274 255 184 244 202 35 35 139 77 103 108 111 115 191 6 , 95 120 181 E. Earthy salts of the urine, Endorlin, his analysis of the ash of blood, Epithelium, . Ewe, milk of, . . . . Extractive matters of the blood, urine, 24* 38 182 34 202 157 35 282 I N D E X. Fat, detected in organic mixtures, ■ the urine, Fat-globules in milk, Fatty matters of the blood, excess of, in the blood, Fermentation test for sugar, Fibrin, . . . excess or deficiency of, in the blood, Fibrinous casts, Figuier, his mode of analyzing blood, Fixed alkaline salts of the urine, Fusible calculi, .... G. Gall stones, . Gelatine, Globules, organic, Glutin, . Goat, milk of, Gouty concretions, H. Haiklen, his analysis of the ash of milk, . Healthy urine, ...... Heller's test for bile, . . . . . Hempseed calculi, ..... Hippuric acid, ...... excess of, in urine, Human milk, composition of, . Hydrochloric acid, detection of, in organic mixtures, &c. quantitative determination of, Hydrocyanic acid, detection of, in organic mixtures, &c. quantitative determination of, Scheele's test for, sulphur test for, Imperial measure, ..... Incombustible calculi, examination of, Iodine, detection of, in organic mixtures, &c, in the urine, .... Iodide of potassium, detection of, in organic mixtures, &c. Kiestien, Kreatine, Kreatinine, Lactic acid, Lactine, Lead, detected in water, K. L. ' 73, 100 199 . 158 187 . 64 . 155, 225 . 186 68 . 185 36 . 136 . 143 217, 227 . 72 227 . 202 144 . 200 25 . 71 137 . 32 . 57, 90 . 201 261 . 263 268 . 271 269 . 269 277 . 141 251 79, 104 258 . 74 35 . 35 198 . 198 247 INDEX. 283 Lead, detected in organic mixtures, &c, . quantitative determination of, . Lecanu, his analysis of blood, Lehmann, his analysis of bone, of urine, L' Heretier, his analysis of milk, Liebig's test for urea, Liquor sanguinis, Lithic acid, .... excess of, in the urine, detected in organic mixtures, . Lithate of ammonia, excess of, in the urine, potash, soda, . . . . M. Marchand, his analysis of urine, Margarine, .... Marsh's test for arsenic, . Maumene's test for sugar, Measure, imperial, Meconic acid, .... Mercury, detection of, in organic mixtures, &c, quantitative determination of, Microscopic examination of urinary deposits Milk,..... adulteration of, containing blood, pus, detected in organic mixtures, globules, human, composition of, . of animals, morbid, quantitative analysis of, sugar of, . Milky blood, Miller, his analysis of urine, . Mixed animal fluids, examination of, Morbid blood, . bone, milk, . mucus, urine, qualitative examination of, Moore's test for sugar, Morphia, .... Mucus, . • . excess of, in the urine, quantitative analysis of, morbid, N. Nasse, his analysis of mucus, Nitrate of urea, 211 29 284 INDEX. Nitric acid, detection of, in organic mixtures, &c. in stains on clothing, . PAGE 263 265 0. Oleine, ..... Opium, detection of, in organic mixtures, &c. Organic globules, .... Osmazome, . Oxalate of lime calculi, deposits, of urea, .... Oxalic acid, detection of, in organic mixtures, quantitative determination of, 230 271 72 35 137 75, 102 28 265 268 P. Pettenkofer's test for bile, Phosphate of ammonia and magnesia calculi, Phosphate of lime calculi, Poisons, detection of, in organic mixtures, &c, Prosch, his analysis of bone, Protein, ..... Prussic acid, detection of, in organic mixtures, &c quantitative determination of, Scheele's test for, sulphur test for, Purpurine, .... Pus, ... quantitative analysis of, . in the blood, . in milk, .... Pyin, ..... . 135 134 . 233 224 . 155 £C, 268 . 271 269 . 269 58, 92 . ' 71 98*, 212, 227 214 . 194 206 . 227 Qualitative examination of calculi, morbid urine, Quantitative analysis of albuminous urine, blood, bone, diabetic urine, healthy urine, milk, mucus, . pus, . determination of arsenic, antimony, copper, hydrochloric acid, hydrocyanic acid, lead, mercury, oxalic acid, sulphuric acid, 139 80, 104, 112 . 126 161 . 218 120 . 41 202 . 209 214 . 241 243 . 255 263 . 270 252 . 247 267 . 261 INDEX. Reduction test for arsenic, Reinsch's, . R. S. Saline matters of the blood, excess or deficiency of, in the blood, in milk, Salts, alkaline, in the urine, ammoniacal, in the urine, earthy, in the urine, Semen, ..... Serolin, ..... Simon, his analysis of blood, . milk, urine, . Solid matters in urine, Specific gravity of urine, Spermatozoa, .... Stains of blood identified, Starch granules, .... Stearine, .... Sugar, detected in organic mixtures, fermentation test for, Maumene's test for, Moore's test for, Trommer's test for, in the blood, Sugar of milk, .... diabetic, .... in urine, estimation of, tests for, Sulphate of indigo, detection of, in organic mixtures Sulphuric acid, detection of, in organic mixtures, &c in stains on clothing, quantitative determination of, Triple phosphate of calculi, deposits, Torula, Trommer's test for sugar, Troy weight, T. U. Urate of ammonia, calculi, . excess of, in urine, of lime in calculi, of potash, . of soda, in the blood, 286 INDEX. Urea, .... detected in organic mixtures, excess of, in urine, in the blood, Liebig's test for, nitrate of, . oxalate of, . Uric acid, . . calculi of, . ■ detected in organic mixtures excess of, in urine, in the blood, . Urina chyli, .... potus, .... sanguinis, Urinary calculi, deposits, examination of, . microscopic examination of, . Urine, albuminous, quantitative analysis of, chylous, .... containing albumen, bile, . blood, cystine, fat, iodine, &c, . oxalate of lime, . pus, . semen, urate of soda, diabetic, quantitative analysis of, healthy, average composition of, quantitative analysis of, specific gravity of, morbid, qualitative examination of, Urine, with excess of alkaline salts, earthy phosphates, extractive matters, hippuric acid, mucus, urate of ammonia, urea, . uric acid, . weight of solid matter in, . Urinometer, .... Valentin, his analysis of bone, Venous blood, composition of, Vernois and Becquerel, their analysis of milk, Vesical mucus, . . Von Bibra, his analysis of bone, 224 181 202 . 34, 57 222, 224 INDEX. 287 w. PAGE Water, detection of lead in, ...... 248 excess of, in the blood, ..... 184 extract, ........ 35 Weights and measures, . ..... 277 Wright, his analysis of pus, ...... 216 X. Xanthoproteic acid, ....... 154 Z. 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With numerous illustrations. {Now Ready.) LEE ^ROBERT) M D—Clinical AIidwifery; comprising the Histories of Five Hundred and Forty-five Cases of Difficult, Preternatural, and Complicated Labor, with Commentaries. From the second London edition. In one royal 12mo. volume, extra cloth, of 238 pages. t i noPTTr n? A Al D —Pneumonia; its Supposed Connection, Pathological and Etiological, ^ wUhMitimnali F^verSuZg an Inquiry into the Existence and Morbid Agency of Malaria. In one handsome octavo volume, extra cloth, of 600 pages. r A ROCHE CR) M D -Yellow Fever, considered in its Historical, Pathological, Etiological, LiTThtEra(Pei't?calReiSo„s. Including a Sketch of the JtaJ^^'^J PhiiBf nearly 600 pages. WILSON (ERASMUS), M.D., F.R.S.—The Dissector's Manual; Practical and Surgical Ana- tomy. Third American, from the last revised and enlarged English edition. Modified and rearranged by William Hunt, M.D. In one large and handsome royal 12mo. volume, leather, of 582 pages, with 154 illustrations. (Now Ready.) WILSON (ERASMUS), M.D., F.R.S.—On Diseases of the Skin. Third American, from the third London edition. In one neat octavo volume, of about 500 pages, extra cloth. WILSON (ERASMUS), M.D., F.R.S. — On Constitutional and Hereditary Syphilis, and on Syphilitic Eruptions. In one small octavo volume, beautifully printed, with four exqui- site colored plates, presenting more than thirty varieties of Syphilitic Eruptions. WILSON (ERASAIUS), M. D., F.R. S—Healthy Skin; a Treatise on the Management of the Skin and Hair in Relation to Health. Second American, from the fourth and improved London edition. In one handsome royal 12mo. volume, extra cloth, with numerous illus- trations. Copies may also be had in paper covers, for mailing, price 75 cents. (Now Ready.) WILLIAMS (C J. 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YOU ATT (WILLIAM), Y. S.—The Dog. Edited by E. J. Lewis, M. D. With numerous and beautiful illustrations. In one very handsome volume, crown 8vo., crimson cloth, gilt Illustrate €»iaj0gtt*. Blancbard & Lea have now ready a detailed Catalogue of their publications, in Medical and other Sciences, with Specimens of the Wood-engravings, Notices of the Press, Ac &c formine a pamphlet of sixty-four large octavo pages. It has been prepared without regard to'exDense and may be considered as one of the handsomest specimens of printing as vet executed in this country. Copies will be sent free, by post, on receipt of two three-cent postage stainns Detailed Catalogues of their publications, Miscellaneous, Educational, Medical &c furl nished gratis, on application. ' ' t,J 1UI^ >ny i NATIONAL LIBRARY OF MEDICINE NLI1 031^0351 0 NLM031903590