M UNITED STATES OF AMERICA FOUNDED 1836 WASHINGTON, D. C SPO 16—67244-1 A DISSERTATION ON THE SOURCES OF Malignant Bilious, or Yellow Fever, AND MEANS OF PREVENTING IT: SUBMITTED TO THE EXAMINATION OF THE REV. JOHN EWING, S. T. P. PROVOST; THE TRUSTEES & MEDICAL FACULTT, OF THE UNIVERSITY of PENNSYLVANIA, On the sixth Day of June, 1799, /'"~\>iiC>- FOR THE DEGREE OF ! / V, -^£'4r' DOCTOR OF MEDICINE^A 0 fS^ _____ ':v'|Y 1 By WILLIAM G. CHALWILL, of Tortola, MEMBER OF THE PHILADELPHIA MESICaL AND CHEMICAL SOCIETIES PHILADELPHIA: PRINTED BY WAY & GROFF, No. 48, North Third-Street. 1799. TO PHILIP SYNG PHYSICK, M. D. THIS DISSERTATION IS DEDICATED, AS A TESTIMONY OF THE SINCERE FRIENDSHIP, AND GRATITUDE, PF HIS FORMER PUPIL, W. G. CHALWILL. 4CM 3SS '// 9 X r^> -y? ^■r/^>~ A DISSERTATION, fcfc. jLJEFORE we enter on the immediate confedera- tion of the fubjecT: of this diflertation, it may not be improper to introduce a few general remarks, which appear neceflary, in order to be underftood in fome opinions which will be delivered therein. Fever, from whatever caufe it may proceed, I conceive to be the fame. This can be more clearly comprehended, from the definition given of it, by Dr. Rufh, the profeffor of the inftitutes of medicine, in the Univerfity of Pennfylvania. He defines it to confift of, irregular, morbid, or convulfive ac- tion, in the blood-veffels. It is no objection to this definition, that in fome fevers, there occurs a defect of action, as this defect is certainly morbid. There is but one remote caufe of fever, and that is ftimulus. This we conclude, from many fub- flances, fuch for inftance as opium, fpirituous li- quors, &c. which are univerfally acknowledged to be flimulant, and many others, from the animal, vegetable, and mineral kingdoms, by their external 6 or internal action on the body, producing genuine fever. Like the exhibition of thefe violent poifons in exceffive quantities, in proftrating the fyftem be- low the point of re-action, the remote caufes of malignant epidemic difeafes, have produced fimilar effects, and like them, in fome inftances, almofl immediate death. In the plague, and yellow fever, this has been particularly noticed by different wri- ters. During the prevalence of thofe difeafes, in- ftances have frequently occurred, of perfons dying within a very few hours, after having been attacked; and have experienced little or no inconvenience, until a very fhort time previous to their death. Having delivered thefe obfervations, we mail pro- ceed with our inquiry into the fources of malignant, bilious, or yellow fever. The opinions, which have been entertained on this, as on every other point, in, and connected with, medicine, have been as various, as plaufibi- Iity or improbability, could give fcope for. The examination of the variety of opinions, which pre- vail, even at the prefent day, would far exceed the limits prefcribed for a thefis, and cquld not be at- tended with any evident advantage. The generality of phyficians, however, agree in fuppofing, that the effluvia or miafmata, arifing 7 from putrefying animal and vegetable fubftances* are the caufe of this difeafe. This opinion we fhall adopt, in the fucceeding pages. It would be pro- per in this place to fpeak of the nature of thefe effluvia, but it will be readily perceived, that on this fubject we can fay nothing, with certainty, as the prefent ftate of fcience affords us no means, by which we may detect their prefence or determine their qualities. It is even a difputed point, whether during the prevalence of epidemics, there is an ad- dition of fome peculiar matters, or a deficiency or excefs, in the natural component parts of the at- mofphere. We can therefore only judge of them, by their effects. There are,, however, three facts which have been noticed, with refpect to epidemics, which are wor- thy of our attention. I. That the inflammatory conftitution of the air, which difpofes to them, extends its influence over confiderable portions of our globe at one and the fame time. While the yellow fever was epidemic, in many parts of the United States, during the years 1793 and 1794, it was at the fame time epidemic in mofl of the Weft Indian iflands. The difeafes which occurred at fea, during thofe years, were obferved to aflume a higher grade of action. From this we may conclude, that the furface of the ocean itfelf, was 8 not exempted from its influence. Thucydides tells us in his account of the plague at Athens, that it pre- vailed at the fame time in part of Ethiopia, in Egypt, in Lybia, and over a confiderable extent of the Per- fian dominions. Procopius and Evagrius tell us that the plague which broke out at Conftantinople, during the reign of the Emperor Juftinian, lafted fifty-two years, and fpread its influence over the whole earth. II. That it continues many years under every viciflitude of weather. III. That during its continuance, it caufes all other difeafes to affume a more inflammatory grade of action, and hence we derive the propriety of faying, the reigning epidemic. In fupport of the two laft mentioned facts, we may affert, that the difeafes of the United States, have been uniformly obferved to be more violent, fince the general epidemic of 1793. This has been evinced by their requiring the refpettive modes of treatment for curing each of them, to be ufed more extenfively, to prove effectual, than they did pre- vious to that period. Since, therefore, we know fo little of the na- ture of the caufes, or rather miafmata, we muft 9 content ourfelves with an inveftigation of the four- ces from whence malignant bilious, or yellow fever arifes; and in this we can probably proceed, with fome degree of certainty. We fhall commence with thofe fources which operate molt extenfively, and proceed with thofe which have been more confined in their influence. The fources which prefent themfelves for our atten- tion, are, I. Marfhy and fwampy grounds, ftagnating ponds and low lands, which have been overflowed with water, and in which have been depofited, fubftances proper for putrefaction, from the influence of the heat of the fun. To prove that thefe fources do pro- duce the caufes of yellow fever, it is only neceffary that we fhould attend to a few well authenticated facts. It is a remark, functioned by univerfal experi- ence, that low countries and lowland fituations, are .always unhealthy, provided they abound with marines. Dr. Lind, among his figns of an un- healthy country, places a fwampy foil as the firft, and moft certain. The province of Guiana, remarkable for its low fituation and fwampy foil, continued to prove a B 10 grave to thofe who went to fettle there, until means were taken to render it healthy, which will be men? tioned hereafter. It may not be improper to remark in this place, that a certain concentration of the marfh miafmata, ^appears neceffary, to produce yellow fever. l Where this concentration does not take place, the effluvia produce fevers of an inferior grade. We con- clude this, from the higher and lower grades of fever, proving alternately epidemic in the fame fituations; the higher grade prevailing in thofe feafons, moft favourable for ^ copious evolution of the miafmata. ■•--■-- -- «; The circumftances under which the yellow fever has appeared in many inland parts of the United -States, afford us ample proof of its originating from the effluvia of marines; and as fuch facts are more interefting to us at prefent, we fhall confine our- felves to them. As it is directly to our purpofe, I muft here take the liberty of tranfcribing a document *, from a- «mong thofe accompanying two letters addrelfed to the governor of Pennfylvania, by the academy of medicine of Philadelphia. v ■ r :. . ,* See appendix to thofe letters, (Document C.) 11 " I do hereby certify, that I vifited the farms at and in the vicinity of Red-bank, fituate on the eaft- ern fhore of the Delaware, for the purpofe of in- veftigating the origin of the yellow fever, that raged fo violently amongft them, during the late autumn. I fought every poflible information from the attend- ing phyfician, the families who had been attacked, and from their neighbours. Knowing that a difeafe of this kind might have been derived from domeftic fources, from the city of Philadelphia, and, poffi- bly, from the ihipping performing quarantine, I was exceedingly particular upon thefe points of en- quiry and inveftigation. After examining the do- cuments upon this fubject, I do not hefitate to pro- nounce it the offspring of local caufes. 0 " The moft valuable part of thefe farms confifts in meadows, which .had been overflowed, for ten or twelve days, by a deluge of rain that commenced on the firft of Auguft. The waters gradually dif- appeared, and depofited a fcum that was exceedingly naufeous. The roots of the grafs were dead in ma- ny places for an acre or more in extent; even fix inches below the furface of the earth they were de- ftroyed—the vegetable putrefaction was great, and the fmell arifing from it extremely difagreeable. To this fource I attribute the difeafe that prevailed amongft them. Twenty-nine perfons were attacked in five families; but fo local was th.e calamity, that, 12 although the neighbours kept up a conftant com- munication, by vifiting the lick rooms, and ren- dering their fervices, no perfon, that thefe families recollect, was affected with it, in confequence. And there is but one poffible cafe in which it could have been communicated, by any one of thefe fa- milies to any of the others. " My opinion of the local origin of the yellow fe- ver, derives fupport from its being the idea of the phyfician who attended the fick, and the univerfal fentiment of thofe who have fuffered by it. Docu- ments, entering into detail, to eftablifh thefe, and a variety of other points connected with the difeafe, are fubfcribed by all the perfons alluded to, and depofited among the records of the academy of medicine. Signed, JOHN C. OTTO. March 20th, 1798." At Sheffield, in the Mate of MafTachufetts, a vio- lent bilious fever has prevailed, feveral fucceflive years, which appears to have had a ftrong alliance to yellow fever, from the account given of it by Dr. Buel. In this account, the author, after ftating his facts, relative to the difeafe, has the following words : " That the ftagnant waters in Sheffield, and the ficknefs which prevailed there in 1796, and the other late fickly years, ftand in the relation of *3 caufe and effect, is, I think, a pofition which no perfon capable of reafoning, can withhold his af- fent to, after admitting, and candidly confidering, the facts which I have Hated." In the village of Kenfington, about two miles diftant from the city of Philadelphia, feveral cafes of yellow fever occurred, in the autumn of 1797, which appear to have been derived from marfh effluvia. This little place is furrounded on all fides by marfhy grounds, which are filled with putrefying, dead vegetable fubftances. At Lamberton, on the eaftern bank of the river Delaware, near Trenton, feveral cafes of yellow fever occurred, in the autumn of 1798. The in- habitants endeavoured to trace them from contagi- on, conveyed by perfons from Philadelphia. Hav- ing had an opportunity of examining whether any foundation exifted for fuch a fuppofition, I found none. But on inveftigation, there appeared evi- dent reafon for believing, that they were produced by a confiderable extent of marfhy ground, con- taining a great deal of ftagnating water, and putre- fying vegetable fubftances, that lay in a fouthern direction from Lamberton, diftant about a quarter of a mile. That portion of land, fituate at the conflux of 14 the rivers Delaware and Schuylkill, known by the name of the neck, containing a large tract of marfhy ground, affords us a very good proof of the origin of violent bilious fever from exhalation. Scarce an autumn paffes, but what numbers of the inhabitants are affected with fevers, fhewing ftrong marks of an approach to the malignant type, II. From putrefying animal and vegetable fub- ftances depofited in gutters, filthy alleys, in docks, on wharves, in public finks, &c. We have too much reafon to fuppofe, that thefe were the principal fources, of the yellow fever, which has, at different times, defolated the cities of Philadelphia and New York. That thefe fources have operated very ftrongly in producing the dif- eafe, we infer from the obfervations of many refpec- table phyficians, all of which agree, that in the vicinity of fuch places, as above enumerated, the fever began, and raged with more violence, than, in thofe fituations, which were remote from their direct influence. Several cafes, derived from thefe fources, are mentioned in the firft letter of the aca- demy of medicine of Philadelphia, addrefled to the governor of Pennfylvania, on the authorities of Doctors Rufh, Phyfick, Caldwell, and Pafcalis. Dr. Seaman, in his ingenious inquiry into the *5 caufe of the prevalence of the yellow fever in New York, publifhed in the medical repofitory, has given pretty decided proof,' of its originating from thefe fources. As certain parts of this inquiry are directly to our purpofe,- I hope I fhall be excufe^ for trahfcribing thofe which are the moft interefting. " In the autumn of 1791, the yellow, fever was confiderably prevalent in a part of Water-ftreet, in the neighbourhood of PeekVflip, noted, at that time, for having the docks near to it, loaded with every kind of filth that could be fcraped up out of the adjoining flips, which had been long collecting every fpecies of corruptible materials, that the citi- zens wifhed to get rid of. " In 1795, that part of the town, that bore the chief burthen of our calamity, was remarkably dif- linguifhed, by peculiarity of circumftances and fi- tuation (aided by the Angular regularity of our Tains), feemingly well calculated for the aceumu, lation and decompofition of all kinds of perifhable animal and vegetable fubftances. " The chief prevalence of the difeafe, in 1796, feemed evidently fixed, where, from our former experience, we ought reafonably to have expected it. For no doubt, at that time, the neighbourhood of the Whitehall, from the nature of materials, 1.0 wherewith a large dock was there filling up, aided by the noifome exhalations, from the expofed bot- tom of the Exchange-fhip at low-water, muft cer- tainly have been rendered the moft noxious part of the city. Four deaths from the yellow fever occur- red, during thatfeafon, within fifty yards of where Roofevelt-ftreet drain empties itfelf into an inlet, which was then open quite up to the foutherly fide of Water-ftreet; the bottom of which was fre- quently, in part, left bare, even at high water. Eve- ry ebb-tide expofed, at leaft, eight hundred fquare yards of its furface, covered with the numerous perifhable materials, furnifhed by the different ■ftreets, of that crowded part of the town, which defcend into this common.fewer, in addition to the other putrid matters, that fuch handy places are always collecting.'* : ■ , The yellow fever was generated in the year 1762, near the draw bridge, in Philadelphia, by the nox- ious effluvia, arifing from putrefcent matters, col- lected from all parts of the city, in a well known receptacle, at that place. The following communication, from Dr. George Davidfon, of the ifland of St. Vincents, to Dr. Rufh, decidedly fhews, the origin of yellow fever, to be from the effluvia difcharged from putrefying animal and vegetable fubftances. *7 " The yellow fever is evidently produced by a peculiar ftate of the air, and by marfh exhalations. The fituation of thofe habitations where it firft ap- pears, near to ftagnant water, or fwamps, point out this to be its origin. The governor's gu.ird on this ifland was ftationed in an old bathing houfe. The ftream of water which had run through it, had been diverted from it > but a quantity of mud and filth, had been allowed to accumulate in a watering trough near the door; in confequence of which, feveral of the guards were feized with the ufual fymptoms of yellow fever. Above ten died before the caufe was difcovered, and immediately upon removing it (the filth collected in the watering trough) the guard became healthy." Many fources of inferior note, have at different times given rife to mJttfflmnl fever, the moft import- ant of which we fhall now proceed to mention. i. The noxious air difcharged from putre- fying animal and vegetable fubftances, contained in the holds of fhips. A confiderable fource of the yellow fever, which raged in the fouth-eaftern part of Philadelphia, in the year 1797, was attributed to the foul air emitted from the fnow Huldah, from - Hamburgh, and fhip Navigation from Marfeilles, from fome of the materials which compofed their G i8 cargoes, putrefying in their holds, during their voy- ages. The crews of thefe veflels continued healthy, from their leaving the ports from whence they came until they difcharged their cargoes, at the wharves in this city, when feveral of their crews, and many refidents near thofe wharves were immediately feiz- ed with the fever. At Tortola, a fever was produced in the month of June, in the year 1787, on board the fhip Britan- nia, Capt. James Welch, from the noxious air generated from a few bufhels of potatoes, which deftroyed the captain, mate, and moft of the crew, in a few days. Two failors were affected with a malignant fever on board the fhip .-----, Capt. Thomas Edgar, in the month of March, 1797, from the noxious air produced by wine that had putrefied in the hold of the fhip, one of whom died, foon after her arrival at Philadelphia. In the month of June, 1793, tne yellow fever was generated by the noxious air, emanating from fome rotted bags of pepper, on board a French Indi- aman, which was carried in the port of Bridgetown in Barbadoes, by the Britifh letter of marque PiL *9 grim. All the white, and moft of the black men employed to remove this pepper, perifhed with yel- low fever, and the foul air affected the town, where it deftroyed numbers of the inhabitants. A yellow fever was produced on board the Bufh- bridge Indiaman, on her paffage from England to Madrafs, in the month of May, 1792, which affect- ed above two hundred of her crew, by putrefying materials confined in her hold. Inftances of yellow fever, originating from . tropical-fources, have occurred in every country and fituation. As they tend to prove that the dif- eafe is produced by the effluvia, of animal and ve- getable fubftances, during their decompofition, I fhall briefly enumerate them, as mentioned by fuch authors, as I have perufed for information, on this fubject. . 1. Cabbage. 2. Potatoes. 3. Pepper, 4. Indian meal. 5. Onions. 6. Mint. 7. Anife and caraway feed confined in the hold of a fhip. 8. Putrefying coffee. The firft cafes of yellow fever which occurred in the month of Auguft, in the year 1793, in this city, arofe from this fource. Dr. Trotter mentions, on the authority of the 20 captain of a man of war, that the whole crews of feveral veffels, in the holds of which, great quanti- ties of this article had been allowed to putrefy, were found dead on their decks, from the imme- diate action of air difcharged on opening their hatches. 9. Cotton that had been wetted on board of a vefiel, that arrived a few years ago from Savannah, in Georgia, at New York. 1 o. Hemp, flax, and ftraw. Dr. Zimmerman relates the fact, of a family that were affected with a malignant fever, generated by a few pounds of putrefying flax. 11. The canvafs of an old tent. 12. Old books, and old paper money, that had been wetted and confined in clofe rooms and clofets. 13. The timber of an old houfe. 14. Green wood confined in a clofe cellar, during the fummer months. 15. The green timber of a new fhip. 16. Theftagnating air of the hold of a fr'-\ 41 17. Bilge water. 18. The ftagnating air of clofe cellars. 19. Air emitted by agitating foul and ftagnating water. 20. A duck-pond. 21. A Hog-ftye. All thefe different fources have been mentioned by authors as having given rife to malignant fevers. Animal fubftances, I believe, feldom produce this grade of fever, when acting alone, although the fol- lowing facts, fhew that it has been in a few inftances produced from thisfource. 1. Dr. Ofborne has (through the medium of the New York medical repofitory) communicated the cafe of a foldier, who had a malignant fever brought on by the miafmata arifing from putrefying beef. 2. Locufts. 3. A whale thrown on the fea fhorein Holland. 4. Human bodies which have putrefied on a field of battle. TCh 5. Raw hides confined in ftores and in the hold of a fhip. 6. Dead fifh putrefying on the fhores of the fea and of rivers. The unhealthinefs of a place called Gambroon, mentioned by Mr. Ives in his travels from India to Europe, over land, is imputed to the quantities of blubber fifh, left annually, during the fummer months, by the fea upon the fhore, which very foon become highly putrid, and offenfive. The fame gentleman tells us, that the Arabs, as a refentment for the injuries they had fuftained from the Turks of Baffora, broke down the banks of the river Tigris, which overflowed the environs of that great city, and from the depofition of dead fifh, a malignant fever was produced which deftroyed 14,000 of its inhabitants, Thefe facts, we hope are fufBcient to prove, that the malignant yellow fever, is the offspring of ani- mal and vegetable putrefaction, The influence of the extremes of heat and cold, on the caufes of this difeafe, are pretty nearly the fame, for they both deftroy them. This is to be admitted with proper Hmitations. Cold weather 23 does it effedually, and exceflive hot weather in fome degree. Moifture, heat, and drynefs of the atmofphere, alternating with each other, appear to be moft favourable for their formation, and a chil- linefs in the air fucceeding thefe, the moft effedual means, of bringing them into adion. This fuggefts to us the propriety of accommodating our drefs to the changes of the atmofphere, to prevent the mi- afmata from ading on our fyf terns ; the change from a higher, to a lower temperature of air, rendering them more fufceptible of morbid adions, from an increafe of excitability. There are many other ftimuli, which, by their adion on the body, produce moft of the fymptoms of ntehg*£n»t fever. To examine all of them would far exceed the limits of this differtation. We may however juft enumerate fome of them. i. Opium. 2. Poifon of a mad dog. 3. The poifon of the viperi 4. Variolus infedion. 5. Many poifonous vegetables. 6. Hydrogene gas. This fluid has been long 24 confidered inert, and depriving animals of life, mere- ly by a negative adion, in preventing the accefs of oxygenous gas to their lungs. Dr. Woodhoufe hav- ing inhaled a confiderable quantity of this air, to convince the medical clafs of its innocence, was in confequence of it, feized with a highly inflammatory fever, which yielded only to copious depletion. 7. The poifons of certain fpiders, and of the fcorpion. 8. Arfenic. 9. Certain concentrated mineral acids, and metal- lic falts, taken into the ftomach in large quantities. 1 o. The adion of fire. From the view we have taken, of the fources of malignant yellow fever, it is% evident, they may exift in any part of the world. This being admit- ted, it neceffarily follows, that it is the height of abfurdity, to aflign it exclufively to any place. This erroneous idea, muft have taken its rife, from the difeafe being more frequently prevalent in certain countries, favoured by the ftates of air, moft pro- per for the evolution of marfh miafmata. The caufes of yellow fever operate in a variety of ways, producing, 25 i. Dyfentery. As an inftance of this, we may juft mention the Duke of Brunfwick's army, in en- tering the French dominions, in the autumn of 1792. This great army, confifting of near 100,000 men, being arrefted in their progrefs on the marfhy plains of Champagne, were obliged, from the pre- valence of this difeafe among them, to retreat, in lefs than two months. 2. Hepatitis. 3. Colic. 4. Colera. 5. Cutaneous eruptions. 6. Leprofy. 7. Scurvy. Dr. Claiborne, in his inaugural thefis, laft year, on the fcurvy, does not hefitate to place marfh effluvia, the firft on his lift of the re- mote caufes of this difeafe. 8. Ophthalmia. Having finifhed our inquiry into the fources, we fhall proceed to the next part of this differta- tion, viz. D 26 MEANS OF PREVENTION. This may with propriety be divided into two parts. i. As it refpeds the caufes, and 2dly, as it re- fpeds the body. As we confidered marfhy grounds, &c. firft, when treating of the fources, we fhall treat of them firft in this place. The only plan we can recommend to prevent thefe extenfive fources of yellow fever, is to culti- vate fuch grounds, where it is pradicable. All countries have been obferved to enjoy a greater degree of health, in proportion to cultivation.— Where this cannot be pradifed, draining by means of canals, has proved very effedual. The now fertile province of Demarara, at one time almoft uninhabitable from its unhealthinefs, has by this means been rendered as healthy as moft tropical countries. If marfhy grounds or .filthy ftagnating ponds, can- not be cultivated or drained, we recommend the planting of trees around them. They may ad in two ways, i. By mechanically diffufing the miaf- 27 mata through the atmofphere, and thereby prevent- ing a fufficient concentration of them to produce difeafe, and 2dly, By giving out a large portion of oxygenous gaz, and thereby purifying the vitiated atmofpheric air. The willow tree appears beft calculated for this purpofe, as being quickeft in growth, and yielding a greater quantity of pure air. With refped to putrefying animal and vegetable fubftances, colleded from negligence, we can do nothing more than recommend their removal. It would be worthy the inveftigation of fome ingeni- ous perfon, to form a plan, for doing this with ceco- nomy, as the expenfe attending their removal, would be far too great, to have it done properly. It is probable this might be done, by eftablifhing a plan for the formation of artificial nitre beds from thefe materials, that would repay the expenfe of re- moving them, by the nitre, which they would pro- duce. This may alfo be done by means of water, To be effedual, it ought to be furnifhed in fufflciency, to deluge the ftreets, whenever occafion may re- quire. Or it may be done by pafling a canal of water through the ftreets, and fweeping the fub- ftances in a ftate of putrefadion into it, that may be conveyed to the river into which the canal may empty itfelf. 28 The eftablifhment of quarantine laws, and of lazarettoes would effedually prevent the produdion of yellow fever from the damaged cargoes of veffels. Two methods have been found ufeful in deftroy- ing the miafmata. i. By nitrous fumigations. This has been high- ly recommended by Dr. Carmichael Smyth, and is now generally adopted throughout the Britifh Navy, where it has been found very effedual. 2. Smoke. Dr. Lind, in his effay on the dif- eafes incident to Europeans in hot climates, relates the fad of two men of war which were cruif- ing in company, on the coaft of Guinea, on board of one, the crew were very fickly, and many died, the crew of the other remained perfedly healthy. Upon examination, it appeared from the conftruc- tion of thefe different fhips, that in the one, which had the healthy crew, the fmoke of the cook's room ufed to fpread itfelf over the whole fhip's decks, and between them ; while in the other, it flew di- redly off from the veffel, with the wind. The means of prevention as they refped the body, are, i. By reducing the fyftem as in preparing the 29 body for the fmall pox. This may be done, i. By a vegetable diet, or a diet of fait meat, which affords lefs nutrition than frefh, at the fame time that it keeps up a more uniform degree of excitement. 2. By blood-letting. 3. Purges. The following fad will fhew the good effeds of this plan of prevention, communicated by Dr. Bor- land to Dr. Rufh. In the month of Auguft, 1797, 109 Dutch artil- lerifts arrived at Port-au-Prince, in the Bangalore tranfport. The crew of this fhip confifted of twen- ty-eight men. It was advifed by Dodors Borland and Jackfon, that the whole detachment fhould be bled and purged freely. The furgeon of the regi- ment, to which this company belonged, complied with their advice, which was accordingly executed. At the period of four months after, when this com- munication was made, only two men out of this de- tachment had died j of the crew only fourteen were living. 2. By eating often, even during the night, which by keeping up an equal degree of excitement, will render the fyftem lefs liable to be adedon, from pre- difpofing debility. 3. Cleanlinefs. 3° 4* Warm bath. 5. Cheerful fociety. 6. Conftant occupation of mind and body. Peo- ple, who were left in Philadelphia, to take care of houfes, during the prevalence of the yellow fever, and who were idle, were very liable to be affeded by it. 7. Gentle exercife. 8. The internal and external ufe of fweet oil. Mr. Baldwin the Englifh conful at Alexandria, in- formed Leopold count Berchtold, that he never heard of a fingle oil porter having died with the plague. From this the count concluded, that olive oil muft poffefs ftrong prophyladic virtues. He tried it in twenty-two Venetian failors, all of which efcaped the plague. From this we may rationally infer, that its effeds would be fimilar in the yellow fever. 9. A blifter. Dr. Gallagher informed me, that during the prevalence of the yellow fever, in Phila- delphia, laft year, he applied blifters to his wrifts, which he kept continually running, and to this afcribes his efcaping the difeafe. 3* i ©. An iffue. Dr. Hodges tells us, that during the plague in London, he had a featon in one of his legs, which gave him great pain every time he was expofed to the contagion in vifiting his patients. It is probable that the pain was caufed by a deter- mination of morbid adion to this artificial weak part. / , It is an unfortunate ftKrtfr, that the generality of mankind are blind to convidion, wherever truth and intereft oppofe each other. In yellow fever this is particularly the cafe. Notwithftanding the numerous, decided proofs, brought forward by men and literary bodies, of the firft eminence, of the domeftic origin of this difeafe, yet there are not wanting many who believe, it owes its origin to importation. But as the prefent progreffive and diffufive ftate of fcience, is highly unfavourable to the continuance of error; the friends of truth, muft look forward to a period, which I hope is not far diftant, when, from the general adoption of their principles, the inhabitants of fickly cities, and country fituations, will, by their exertions, pre- vent the recurrence of thefe difeafes, by a removal of their caufes. FINIS. WZ XI0 nil c I