Dunglison's American Medical Library. ESSAYS SOURCES AND MODE OF ACTION FEVER, BY WILLIAM DAVIDSON, M. D., IKNIOR PHYSICIAN TO THE GLASGOW ROYAL INFIRMARY, ETC. ETC.; AND ALFRED HUDSON, M. B., T. C. D„ PHYSICIAN TO THE NAVAN FEVER HOSPITAL. PHILADELPHIA: PUBLISHED BY A. WALDIE, 46 CARPENTER STREET. 1841. * 3—d • I. THACKERAY PRIZE ESSAY. Essay on the Sources and Mode of Propagation of the Con- tinued Fevers of Great Britain and Ireland. BY WILLIAM DAVIDSON, M. D., Senior Physician to the Glasgow Royal Infirmary, Lecturer on Materia Medica, Member of the Faculty of Physicians and Surgeons of Glasgow, &c. CHAPTER I. On the Sources of Continued Fevers. Numerous kinds of continued fevers have been described by authors; but many of these have been found, on investigation, only particular varieties, in place of being distinct species. This has been particularly the case with typhus, the most prevalent kind of continued fever in this country; and it may be accounted for, from its numerous and diversified complications giving rise to various and multiform symptoms. The pathology of typhus, how- ever, of late years has been considerably advanced; and it is now established, that this disease may be either simple or complicated, with organic affections of one or all of the different cavities of the body. We shall not, at present, enter into any discussion respecting the various kinds of continued fever that are to be met with in the United Kingdom; but as perspicuity in arrangement requires some classification, we shall adopt the following, reserving the illustra- tions upon which this classification is founded for a future part of the essay:— 1. Typhus. 2. Febricula or Simple Fever. 3. Gastric or Intestinal Fever. These affections seem to be distinct species of disease, differing in their symptoms, causes, and laws; and are generally treated in private practice and in hospitals as continued fevers. To this list 4 DAVIDSON ON THE CAUSES OF FEVER. may, perhaps, be added bronchitis, which, although an inflamma- tory affection, is more frequently confounded with them than any other disease. Sect. I.—Sources of Typhus. It appears to us quite unnecessary here to describe what is un- derstood by typhus fever; as we assent to the general correctness of our standard authors upon this subject, and as some of their descriptions will be quoted in another part of this essay. At the same time, it may be remarked that typhus possesses an advantage over the other forms of continued fever, in having a distinctive characteristic, viz. the eruption, which is present in none of the others, and which is now almost universally acknowledged as de- cisive of its existence. It must, however, be admitted that typhus can and does occur, without its characteristic eruption ; but it is equally certain that the large majority of patients who have deci- dedly the general typhoid symptoms, are more or less spotted with this efflorescence. It is therefore the sources of typhus, as gene- rally so characterised, which we mean to trace in this section. There is considerable diversity of opinion amongst British phy- sicians respecting the causes of continued fevers; but certainly the majority of authors have adopted the belief that typhus is propa- gated by contagion. The opinion of the majority appears to be supported by the facts connected with the progression of the dis- ease ; it shall therefore be our object to establish this point. It is not intended, however, to enter into any speculations respecting the primordial source of the contagion of typhus; for the sources from which it, as well as that of other contagious fevers, originated, is involved in absolute obscurity; and though we could trace them to the most remote era in antiquity, the same difficulty would be en- countered. Some authors, apparently to get rid of this difficulty, and to account for the occurrences of typhus where no contagion could be traced, have adopted the opinion that it may be generated by common causes, such as impure air, filth, &c, and be after- wards capable of propagation by contagion.1 The argument of analogy is directly opposed to this belief; for if, in nature, there be no exception to the law, that two causes are never required to pro- duce precisely the same effect, it will follow that whatever cause can be best reconciled with the phenomena of typhus, must be con- sidered the true source of the disease. But, in order to apply this principle more immediately to the subject, it may be necessary to appeal to the various morbid poisons, the laws of which are known and generally admitted. The first we shall notice, are those which are admitted by all writers to be propagated by one cause only; 1 The terms contagion and infection are used synonymously, as indicating the ponderable or imponderable matter, which is generated in a diseased living body, and which is capable of producing the same disease when applied to another. DAVIDSON ON THE CAUSES OF FEVER. 5 viz. matter, whether ponderable, as the pus contained in a variolous pustule, or imponderable, as the effluvia issuing from a patient labouring under small-pox. Measles, scarlet fever, hooping-cough, are propagated only by the effluvia which are generated by the patient; and though the material body by which it is effected can- not be collected into vessels, like the various gasts, still the proofs, upon which their contagious qualities are based, are as unquestion- able as those of small-pox. Almost all the contagious diseases of the skin, such' as syphilis, scabies, the yaws, sivvens, &c, furnish ex- amples of propagation by only one cause, viz. contagion. There are no doubt authors who maintain that some cutaneous diseases are generated by filth, &c, such as some of the infectious species of porrigo; but of this there is no proof; and in all probability it is equally unfounded, as was a similar hypothesis respecting the origin of scabies. These diseases always retain the same charac- teristics; the one is not convertible into the other; and no known combination of them can generate a new contagion capable of per- petuating a new disease. A specious objection might be brought forward against the introduction of an analogy from chronic con- tagious diseases, which are only propagated by contact, according to the general belief; and besides are regulated in other respects by different laws, whereas typhus is propagated only by effluvia. It is quite evident that a class of diseases may be recognised by one leading and undeviating law, while they differ in many of their subordinate characters; and yet this peculiar law of similarity be- tween them may be as certain and definite as if they had been united into one family by all their habits. The effluvium which issues from a small-pox patient must be as essentially matter, as is the fluid of a variolous pustule; for though the first cannot be col- lected in a separate form, it must possess one or other of the pro- perties of small-pox matter, else it could not induce the disease: the only difference between them consisting in this, that the conta- gious matter is fluid in the one case and effluvial in the other. It is necessary that the foregoing observations respecting contagious diseases be kept in view; for upon the analogy between them and typhus we mean to establish an argument, that the latter disease can only be propagated by one cause. If it be true, then, that all the contagious fevers known can be propagated only by contagious matter, and by no other cause, however much their contagious qualities, their prevalence, and their fatality may be increased by other causes, it must follow from the law of analogy that if typhus can be proved to be contagious, it must also be propagated only by one cause, viz. contagion. We shall, therefore, endeavour to prove this point; and, in the outset, it may be stated, that we do not mean to fatigue the reader by stories about fornites and persons who have carried the contagion about them for months or years, nor to hunt out a particular individual who has conveyed it from one town to another. In place of accumulating evidence of this kind, which although sometimes very conclusive, is in other cases somewhat 6 DAVIDSON ON THE CAUSES OF FEVER. questionable, we shall select a few facts from the history of our British and Irish hospitals, which, we trust, will be suflicient for our purpose; for if it can be established from these documents that the disease was contagious in all the large hospitals of Britain and Ireland, then it must be more or less so in every other place. In selecting the facts, we shall adduce the most conclusive instances, such as where the whole, or almost the whole, of the attendants of the patients affected with typhus were infected; for were the whole body of evidence existing on this subject accumulated in this essay, the argument would be encumbered, and the proofs perhaps ren- dered less convincing. Those who deny the existence of typhous contagion, may assert that this is unfair, and that those hospitals also should be brought forward, where the medical and other attendants were rarely affected. As we shall, however, notice this and other objections elsewhere, it need not be farther alluded to here. Drs. Barker and Cheyne, in their admirable report of the fever which prevailed in Ireland during the years 1817-18-19, state that "in the hospitals of the House of Industry of Dublin, no clinical clerk or apothecary escaped an attack of the disease ; and on the 20th of January, 1819, it was reported to government that five of the medical attendants of the House of Industry were at that time lying ill of the disease. In the city of Cork, nine physicians, in attendance either on dispensaries or fever hospitals, were attacked ; every medical attendant at the South Fever Asylum, in that city, suffered. At the hospitals of the House of Industry, one hundred and seventy persons were employed in different offices of attendance on fever patients; and from this part of the establish- ment were recorded one hundred and ninety eight cases of fever." In Dr. Crampton's medical report of the department of Steevens' Hospital, it is observed, "that, with the exception of Dr. Harvey and himself, all those concerned in attendance on the patients canght the disease; none of the nurses, none of the porters, barbers, or those occupied in handling, washing, or tending on the sick, escaped, and many of them had relapses and recurrences of fever.'" Dr. Bracken, in his report of the Fever Hospital of Waterford for 1818, states that "there were twenty-seven attacks and relapses of fever among the nurses, servants, and porters, whose number fluctuated according to the demand for them, but who, on an ave- rage, may have been about twenty-two during the year." He far- ther states that "the present year, 1819, bears a close resemblance to the last, in respect to the nurses and servants being attacked with fever, eighteen of the former having suffered under the dis- ease; seven of them once, three twice, and one three times. The apothecary, who had not been long in the hospital, caught fever and relapsed twice. During his illness, a young man, who per- formed part of his duties, was attacked after a" short attendance. A temporary apothecary was then engaged for a few weeks; but he 1 Barker and Cheyne's Report of the Fever in Ireland, vol. i. p. 135. DAVIDSON ON THE CAUSES OF FEVER. 7 had not been many days in his new employment when he also con- tracted a fever."1 Drs. Barker and Cheyne remark that clergymen, who visited typhus patients in Ireland during the epidemic, were also observed to suffer in a very remarkable degree; and they quote the follow- ing passage from Dr. Stokes's Essay on Contagion, which was published at a time when the fever had made little progress in Dublin :—" The deaths from fever recorded in Saunders's News- Letter, from August 1st to December 12th following, are sixty- four, and of these nineteen are of clergymen of some of the different persuasions, or of medical men of different descriptions, which ap- pear greater than the proportion which these two classes bear to the whole of those whose deaths we may suppose were mentitfned in that manner."3 Dr. Tweedie, in his Clinical Illustrations of Fever for 1828-29, observes that " the London Fever Hospital is placed in an open space, situated in the vicinity of the metropolis, close to the Small-pox Hospital. Both these establishments stand in the centre of a large field, where the production of malaria is ex- tremely improbable. I can state from the most authentic sources, that every physician who has been connected with it, with one ex- ception (the late Dr. Bateman), has been attacked with fever during; his attendance, and that three out of eight physicians have died. The resident medical officers, matrons, porters, laundresses, and domestic servants, not connected with the wards, and every female who has ever performed the duties of a nurse, have one and all in- variably been the subjects of fever; and to show that the disease may be engendered by fomites in clothing, the laundresses, whose duty it is to wash the patients' clothes, are so invariably and fre- quently attacked with fever, that few women will undertake this loathsome and frequently disgusting duty. Lust summer, a most convincing illustration of contagion occurred. The present resi- dent medical officer was attacked with fever, and it was necessary, in consequence, to appoint some one to perform his duties during his illness. The first person who officiated for him resided con- stantly in the house during the day, but took the precaution of sleeping at home. He was, of course, very much exposed in the wards in the performance of his duties. These, however, were soon interrupted by an attack of fever, which confined him for a considerable time. The duties were then undertaken by a medical pupil, who had completed his education, and entered the hospital in the most robust health. He had been taught, and did implicitly believe, in the non-contagious nature of fever, and ridiculed the idea of any personal danger from residing in the hospital. He per- formed the duty of house-surgeon for ten days only, when symp- toms of a severe fever appeared."3 ' Barker and Cheyne's Report of the Fever in Ireland, vol. i. p. 276. 2 Ibid. vol. i. p. 138. * Tweedie's Clinical Illustrations of Fever, p. 87. 8 DAVIDSON ON THE CAUSES OF FEVER. Dr. Tweedie also adduces some important facts connected with the fever which prevailed in Edinburgh during the year 1817, which are the following:—Owing to the prevalence of fever at Edinburgh in 1817, it was necessary to apply to government to permit dueensbury House to be employed as a fever hospital: " In the immediate neighbourhood of this extensive building fever was decidedly less prevalent than in any other quarter of the town. All those, however, who resided in the hospital, including the resident house-surgeon, clerks, apothecary, and nurses, were successively attacked." The following is Professor Alison's report on this sub- ject. " When dueensbury House was formerly occupied by fever patients, every resident clerk and every nurse in the house were successively affected with the disease; and since it was reopened in December last (1826), the resident physician, two of the clerks (who have not been resident, but have been several hours in the day in the house), the apothecary, several servants, and all the nurses except two, in all above forty individuals, who had neces- sarily close intercourse with the sick there, have had fever. If this be the effect of a malaria, it must be a very virulent and effective one, and it is reasonable to expect that some record of similar visitations in the former history of the building would be found. But dueensbury House has existed for about a century; it was long" occupied as a private dwelling-house by the noble family of that name; afterwards it was occupied by a number of families, and afterwards as a soldiers' barrack; and yet no record can be found of its having been, during these changes, the seat of an epi- demic fever. If a malaria has existed, therefore, in that house, it must, on both occasions, have sprung up exclusively at the times when fever patients were removed thither and lasted only during their stay. During the present epidemic (1827-28, as well as that of 1817-19), many of the clerks and nurses employed in the Royal Infirmary have taken fever. Since November last, six of the clerks employed in the clinical wards only, four of those employed in the ordinary wards, and twenty-five nurses or servants have taken fever. All these persons had necessarily frequent and close inter- course with the fever patients in the house, having been employed more or less constantly in the fever wards, excepting only four of the servants. Of these four, two had been employed in the laundry, where the linen from the fever wards was washed. One was a porter employed at the gate, who would, of course, have communi- cation with the fever patients at their entrance and dismissal, as well as with their relations coming to visit them; and one was a nurse employed in the servants' ward, but who was in the habit of visiting the fever wards." He adds further: " No one of the nurses, whose duty has confined them to the medical or surgical wards, where no fever patients were admitted, has taken fever, with the single exception of the woman in the servants' ward above men- tioned; and of the numerous patients in these ordinary wards, the only one who has taken fever, within my knowledge, during the DAVIDSON ON THE CAUSES OF FEVER. 9 present year, was a patient in the men's general clinical ward, who lay in the bed next the door that communicates with the clinical ward.'" Dr. West, in his account of the cases of typhus exanthe- maticus that occurred in St. Bartholomew's Hospital in 1837-38, states that "since last summer, eleven gentlemen who were in the habit of frequenting the hospital have been attacked by the fever, to which three have fallen victims ; sixteen nurses and twenty-one patients admitted for other affections, have likewise suffered from the disease, which terminated fatally in ten instances, and I do not doubt but that many similar cases occurred which did not come under my notice."2 Dr. Roupell, also, gives similar testimony in reference to St. Bartholomew's Hospital, and states that " amongst the nurses in attendance upon the sick, in that establishment, infec- tion was almost universal."3 In the Glasgow Fever Hospital, which is capable of containing 220 patients, during the last six or seven years almost every clerk and nurse of that establishment have caught fever while acting in the wards, unless they had previously laboured under the disease. On the other hand, the nurses con- nected with the medical and surgical wards, in the adjoining build- ing, have almost uniformly escaped. Occasionally a case has appeared in the medical and surgical wards; but this fact ought to be coupled with the statement, that now and then typhus cases are sent, by mistake, into the medical wards, and cases of bed-sores, gangrene of the feet, &c. are transmitted from the fever hospital to the surgical wards. Dr. Cowan states that "All the gentlemen who have acted as clerks in the fever hospital for many years past have been attacked with fever, unless they had it previously to their election. During last year, twenty-seven of the nurses of the establishment were seized with fever, and five of them died: several of the students have been affected. One gentleman who acted as apothecary died in the house; and if I have escaped, it must be attributed either to being past the period of life at which fever usually takes place, or to my being secured by having had two dangerous attacks at an earlier period of my career, when acting as physician's clerk in the infirmary, during the epidemic of 1816- 17-18."" Dr. Mateer gives a table of 9,588 cases, which were admitted into the Belfast Fever Hospital, from 1818 to 1835, showing the number of patients who had any communication with affected persons, either by residence in the same house, or by belonging to the same family. He draws the following conclusion from the table: "It thus appears that the number of families where contagion is trace- able is 1,856, that the total number of persons belonging to them is 7,246, making an average of nearly four individuals to each family; 1 Tweedie's Clinical Illustrations of Fever. Edinb. Med. and Surg. Jour- nal, vol. xxviii. p. 238. *Ibid., July, 1838, p. 143. •Roupell oo Typhus. « Cowan's Vital Statistics, p. 26- 10 DAVIDSON ON THE CAUSES OF FEVER. and that the single cases, where the disease seemed to have arisen from other sources, amount only to 2342."1 This assemblage of facts has been drawn from the large hospitals in England Scotland, and Ireland, and the observations have been made during various years and during different epidemics by gen- tlemen of the highest talents and respectability; their authenticity cannot, therefore, for a moment be questioned. The simple relation of these facts would, we think, with the majority of men, produce conviction that fever was at least contagious in these hospitals, pro- vided the mind was not preoccupied with an opposite theory; but a few observations will tend to produce a proper estimation of this testimony. It is quite obvious, that where a much larger proportion of persons is affected with any particular disease, in any particular place, than occurs amongst the general community, or in any par- ticular grade of society, there must be some local cause for that increased ratio. This has, manifestly, been the result, in the fever hospitals that have been enumerated; for in all, a very large majority of the attendants, and in some the whole of them, were affected with fever. Now, no one will contend, that even amongst the lower classes (who generally suffer from fever to the greatest amount), such a proportion has ever been maintained, even in our most severe typhoid epidemics ; but if the number of hospital clerks be taken and compared with the unaffected number, in the particu- lar grade of society to which they belong, such an attempt would be ridiculous; for the united testimony of the hospital physicians of England, Scotland, and Ireland (whose statements we have already quoted) amounts to this, that almost every clerk of a fever hospital has laboured under fever during some period of his attend- ance upon it. It may be contended, in answer to this argument, that the atmosphere of the hospitals was contaminated by the exhalations arising from the number of patients and the want of proper ventilation ; but the same process of atmospheric deteriora- tion ought to take place, in the medical and surgical wards, if they be equally filled, which is generally the case; and in the latter wards there are often, in addition to the ordinary exhalations, the effluvia arising from wounds, ulcers, &c, yet typhus rarely, and only in sporadic cases, springs up there. The opponents of contagion, however, endeavour to explain the prevalence of fever among hospital attendants by the hypothesis, that the same cause that produced it in the filthy, ill-ventilated houses of the lower classes is in existence in these institutions; viz., a peculiar malaria, generated chiefly in large towns. If this hypothesis were true, it would follow, as a necessary consequence, that the other parts of the building, being similarly situated, would be subjected to the same malarious effluvia, and hence its inmates would be affected with the same kind of disease; but this has never occurred in any of the large hospitals already alluded to, nor in any other, 'Dublin Journal of Medical Science, vol. x. p. 35. DAVIDSON ON THE CAUSES OF FEVER. 11 so far as we are aware, where patients affected with typhus are kept exclusively in one place. Again, it may be asserted by the noncontagionist, when driven to the last extremity, that though malarious effluvium be not generated in an hospital, it may be carried there by the clothes of the patients, and the attendants may be infected by coming into contact with them. The analogy of malarious diseases is in opposition to this belief; for it is not found that a patient labouring under ague infects any person who has not been in the malarious district; neither, according to the general belief, does a patient labouring under yellow fever, when removed from the quarter where he caught the disease, excite contagion in the vicinity of his new residence. But as this supposed typhoid malaria may be assumed to possess something sui generis, an argument stronger than analogy can be adduced, viz., the impossi- bility of carrying any principle of that kind into the wards. It is the practice, in many of the large fever hospitals, to remove the clothes of the patients, to bathe them, shave their heads, and give them clean linen, before they are sent into the wards. This plan is adopted in the Glasgow Fever Hospital, and the following is one of the regulations of the Waterford Hospital. Dr. Bracken states, that " according to one of the regulations of the hospital, every patient has his hair closely cut at the time of his admission ; he is also well washed with warm water and soap, and supplied with linen before he enters the sick ward."1 Sect. II.— On the Analogy of Typhus to Exanthematous Fevers. Having discussed the most important and specious hypotheses which have been brought forward to explain the general and ultra- proportionate prevalence of fever among the attendants of the sick in large hospitals, independent of the operation of contagion, we shall take notice of the general objections to the doctrine of conta- gion in typhus fever; and these maybe comprehended in the state- ment, that it is not characterised by the laws of other contagious fevers. Before entering upon this part of the subject it may be remarked, that more importance is generally attached to this argu- ment than it merits; for though, in the absence of facts, analogy is the most conclusive process of reasoning that can be employed, yet, undoubtedly, when facts are opposed to the application of this principle in any individual case, the facts have the preponderance over the analogy. And, though we were unable to prove that typhus was analogous, in its leading characteristics, to the conta- gious exanthemata, yet if it be admitted that there is no theory which can explain satisfactorily the facts regarding the prevalence of the disease in hospital attendants, except that of contagion, the case would be conclusively determined, even in opposition to the analogy, and would be set down either as an exception, or as one ' Barker and Cheyne on Fever, vol. i p. 259. 12 DAVIDSON ON THE CAUSES OF FEVER. of a new series of contagious diseases. It fortunately happens, however, that the law of analogy will be little violated by com- paring typhus with the contagious fevers, for in its leading charac- teristics it resembles them pretty closely; at the same time it ought to be observed, that typhus fever has only, of late years, been examined with sufficient care, as to many points, connected with its history, laws, and pathology, and that it labours under the dis- advantage of being frequently confounded with other continued fevers, to which, in its early features, it bears an intimate resem- blance ; so that the same certainty of analogical conclusion cannot be expected, as exists among the other exanthematous fevers. We shall endeavour, however, to show, by the facts which shall be quoted, that typhus comes distinctly within the range of their analogy, and that though it is not so regular in its progress, nor so certain in its eruption as smallpox or measles, yet that it differs as little from scarlet fever, in these respects, as the latter differs from smallpox. The principal laws of the contagious exanthemata are the fol- lowing: 1. The contagion can be traced in families, hospitals, schools, &c, and those exposed to it are very generally infected. 2. They only affect persons once during their lives. 3. They are characterised by an eruption, which has a rise, pro- gress, and decline, and the disease cannot be checked in limine. 1. The contagion of typhus is traceable in hospitals, schools, families, §*c. In determining the contagious nature of any disease, it is not necessary that we should be able to trace every case, or even the majority of a particular amount of cases, to a communica- tion with an infected person, or to exposure to a particular fomites; for this would imply that we could, like an American Indian, dis- cover the trail of a patient and trace him through all the windings of a large city, and. besides, should investigate the history of every individual whom he has passed or rubbed shoulders with in every narrow and dirty alley. Even in smallpox, measles, and scarlet fever, any attempt of this kind to trace the contagion regularly would be fruitless, and for the very same reason. Smallpox was, at one period, believed by some authors to originate in filth, because it was found impossible, in numerous cases, to account for its ex- istence in certain localities upon the principles of contagion. Dr. Adams remarks, that " many children born in London live for seve- ral years without receiving the smallpox. In the same neighbour- hood a person arrives from the country, and without any apparent intercourse with an infected person is attacked by the disease."1 Independent of the many exposures to infection, which are per- fectly unknown and undiscoverable by the patient, it is very diffi- cult to ascertain the facts connected with the ordinary movements of a patient, which, in many cases, can only be elicited by tedious 1 Adams on Morbid Poisons. DAVIDSON ON THE CAUSES OF FEVER. 13 cross-examinations; so that this method of determining the point is liable to many objections, and greatly inferior in conclusiveness to the evidence derived from the spread of a disease in any large school or hospital; but, certainly, it tends to prove the doctrine of con- tagion in typhus as much, if not more, than it does in smallpox, &c., as will appear from the following table. The whole of the eruptive cases of typhus, in which this point was investigated, and that were admitted into the Glasgow Fever Hospital from 1st May to 1st November, 1839, are included only in this.table, the males and females being classed together. ! Exposed to Contagion. Uncertain. Cold. Total No. of Cases. Eruptive typhus . . 1 201 Febricula . . . . | 10 Smallpox .... 7 Scarlet fever ... Measles .... 169 28 19 4 2 53 22 1 1 423 60 27 4 3 The number of eruptive cases of typhus admitted into the fever hospital, both in the period included in the above table and also during the previous six months, who have been exposed to conta- gion, we have always found greater than in those affections not characterised by the exanthema; and it is remarkable that, not- withstanding the most careful inquiries, only seven cases of small- pox could be traced to contagion out of twenty-seven. Dr. Cowan states, that "of the patients admitted into the fever hospital last year, 472 males and 589 females, forming 47 per cent. of the whole, either ascribed the origin of their disease to contagion, or had been exposed to its influence."1 The propagation of the typhoid contagion is also intimately con- nected with filth and deficient ventilation; and there are few medi- cal facts better ascertained than the close connection of pestilence with these circumstances. Dr. Hancock remarks, that " the con- nection of plague with filth and impure air, and crowded ill-con- structed cities, and with certain seasons and climates and states of the atmosphere, calculated to engender mischief, though not accu- rately defined, has been so repeatedly observed in different countries as to stand on a far more solid foundation."3 Dr. Bateman, in his Historical Survey of the Diseases of London, states that " Dr. Heberden has collected the most ample and satisfactory evidence of the connection of the plague, and of the malignant contagious fever which generally precedes and accompanies it (if, indeed, they be not modifications of the same disease) with the filth of crowded, ill- ventilated large cities, in all ages and countries." He then quotes Dr. Heberden's remarks: " It has always originated and maintained its head-quarters in the filthiest parts of those cities; as in St. Giles's, 1 Cowan's Vital Statistics of Glasgow, p. 26. 8 Hancock on Pestilence, p. 224. 14 DAVIDSON ON THE CAUSES OF FEVER. in London, in 1665, and in Whitechapel in 1626 and 1636; and in those cities of Europe, which, from natural or political causes, have been backward in adopting the improvements of modern times : the picture of former manners is not exhibited in more lively colours than that of former diseases. The plague visited Denmark in 1764, it raged at Moscow in 1771, and at Cracow still later. The last- mentioned town, Mr. Wraxall says, was not wholly paved till within the last two years, and nothing can be so execrable as the present paving, which scarcely deserves the name. There is not a single lamp in the place; no precautions are used to cleanse the streets, which, of course, become infectious in summer and almost impassable in winter." The following is Erasmus's description of the habits of the English, about two centuries ago: " The floors are commonly of clay, strewed with rushes, which are occasionally renewed, but underneath lies unmolested an ancient collection of beer, grease, fragments of fish, spittle, the excrement of dogs and cats, and every thing that is nasty."1 Dr. Hancock observes, that most writers on the plague have remarked the exemption of Persia from this disease, and he quotes the following passage from the City Remembrancer: " The Persians, though their country is every year surrounded by the plague, seldom suffer any thing by it them- selves; they are the most cleanly people in the world, many of them making it a great part of their religion to remove filthiness and nuisances of every kind from all places about their cities and dwellings."2 Drs. Barker and Cheyne, in their statement of the circumstances which either preceded or attended the epidemic fever in Ireland during the years 1816 and 1817, make the following remarks, which may be assumed as conclusions drawn from the reports of physicians practising in the various provinces, and from the observation of more than 100,000 cases in general hospitals: " When fever commenced in a poor family, or was introduced by a stranger or lodger, it generally extended to all its members. The poor were the chief sufferers, in consequence of their neglect of cleanliness, particularly with respect to their clothing, and the smallness and crowded state of their apartments; evils, at the time, much increased by the extreme poverty which weighed them down. On the other hand the superior classes, whose circumstances were different, their clothing more frequently changed, their persons more cleanly, their apartments less crowded and better ventilated, and among whom seclusion from the sick was practised, in propor- tion to their enjoyment of these advantages, generally escaped the disease."3 Dr. Bateman, after describing the methods to be adopted for pro- moting cleanliness and sufficient ventilation, remarks: "If these simple measures be steadily pursued, no confinement or accumula- 1 Bateman on the Diseases of London, p. 18. 1 Hancock on Pestilence, p. 287. 3 Barker and Cheyne on Fever, vol. i. p. 134. DAVIDSON ON THE CAUSES OF FEVER. 15 tion of morbid effluvia can take place under any state of fever; and the air of the apartment may be breathed, and the bed and person of the patient approached and touched with perfect impunity. If this were not the case, indeed, physicians and nurses, especially those employed in fever hospitals, would have little security for their lives. During the fourteen years, in the course of which I have almost daily been in contact with persons labouring under contagious fever, not only myself but all the nurses have thus been preserved from infection, with one exception, down to the period of the present epidemic." He adds in a note : " It is no disparagement to the system above described that some of the nurses and the matron of the House of Recovery have been infected during the present epidemic, which has kept the wards constantly full. The impossibility of maintaining a free ventilation night and day, dur- ing the cold weather, their perpetual exposure, in close contact, to the breath and discharges of the patients, while feeding, moving, or washing them, changing their beds and linen, and even stripping off their infected clothes on admission, might be sufficient to coun- teract the solitary operation of any general system, however effica- cious. But the truth is, that the ventilation of the house has been very imperfect, and even at the command of the nurses and patients; and the injurious consequences of this imperfection have become so manifest, that the subject is now under the consideration of the committee, while this work is in the press."1 Dr. Hancock quotes the following facts, which illustrate very powerfully the influence of ventilation : " In the year 1819, I had occasion to see a very intelligent physician connected with one or two fever hospitals in Dublin, during the epidemic, who assured me he had seen no proof of the existence of contagion in the disease (typhus) as it appeared in those institutions under his care, where very great attention was paid to ventilation, and where the patients were not inconveniently crowded. But soon after this, I saw another physician no less intelligent, who informed me that in the course of about four months, between 200 and 300 persons were admitted into the Belfast Fever Hospital; and they were frequently so crowded in the wards as nearly to cover the floor with their beds; in which case, although the building is new, airy, and well regulated, the matron, twenty-two nurses, and the apothecary, took the disease; yet it was so mild, that scarcely more than one in fifty died."2 Dr. Prichard relates a striking example of the effects of a good as well as of a deficient ventilation, which occurred in two of the hospitals in Bristol, namely, St. Peter's and the Bristol Infirmary; both of these institutions being under his medical superintendence. " In the former, (St. Peter's,) the medical wards are very small, and it was necessary to place the beds very near to each other, and to 1 Bateman on Contagious Fever, p. 154. 2 Hancock on Pestilence, p. 339. 16 DAVIDSON ON THE CAUSES OF FEVER. put too great a number of patients in a given space. Offensive smells were often perceptible; and it was under these circumstances that the disease was manifestly contagious." In the Bristol Infirmary the wards are lofty and well ventilated. "Here, also, the fever patients were dispersed among invalids of almost every other description. But no instance occurred of the propagation of fever; none of the nurses were attacked, nor were the patients lying in the adjacent beds in any instance infected, though cases of the worst description of typhus gravior were placed promiscuously among the other patients, scarcely two feet of space intervening between the beds."1 Drs. Barker and' Cheyne state that "a remarkable proof was afforded, in Sir Patrick Dunn's Hospital, of a ward, by the pecu- liarity of its construction, protecting the attendants upon the sick from the effects of contagion. The ward alluded to is the fever ward for males, which extends the entire breadth of the left wing of the hospital, being sixty-two feet by thirty-eight. It is twenty feet high, and is subdivided by partitions, of the height of nine feet, into six apartments, two of which are thirty-eight feet by sixteen, and the rest are each nine feet square; the latter contains, with great convenience, four beds each, and the former ten; but on occasions of necessity, the square apartments have held five, and the oblong twelve beds without inconvenience; the partition walls leave two passages, one leading from the door of the wards across its breadth, and another passing in the middle of its length; it is furnished with three large fireplaces, two of which are in the ob- long chambers, one on the north and the other on the south side of the ward, and the third opposite the door, at the end of the passage first described; by this door, the fever-ward opens on the staircase, which is walled and communicates with the corridors of the base- ment and underground stories. The greater number of the win- dows of the ward are sixteen feet from the floor, and in the ceiling are placed two louvres, one toward either end, by means of which and the fireplaces a brisk ventilation is kept up. During the late epidemic, when Sir Patrick Dunn's Hospital, by agreement with government, contained one hundred patients in fever, the male ward was crowded, containing forty-four patients, yet only one nurse was affected with fever: at the same period, the nurses in attendance on the female patients, who were certainly not so much crowded together, were continually taking the complaint, and gene- rally had it with severity."2 In addition to the facts which have now been brought forward, it may be stated, without much chance of contradiction, that, as there is in almost every large town defi- cient accommodation for fever patients in an hospital during an epidemic, overcrowding is an ordinary result, from the anxiety of the directors to relieve the misery of the sick. The Glasgow Fever Hospital is calculated to contain two hundred and twenty ' Hancock on Pestilence. Prichard's History of the Fever in Bristol, p. 88. 'Barker and Cheyne on Fever, vol. i. p. 488. DAVIDSON ON THE CAUSES OF FEVER. 17 patients ; and for nearly two years, namely, during 1836-7, it was generally filled to its maximum, and frequently from ten to twenty additional were accommodated. Now. it is quite obvious, that such a large number of fever patients, all contained in one build- ing, will exhale a prodigious quantity of typhoid effluvium, which must be exceedingly concentrated; and that even the utmost clean- liness, and the greatest degree of ventilation consistent with the temperature that ought to be maintained, would scarcely be suffi- cient for its proper dilution. Drs. Barker and Cheyne remark, in that portion of their report which has been already quoted, that typhus generally spreads in the families of the lower classes, and very rarely in those of the superior ranks. Dr. Cowan states that "the fever was chiefly, nay almost wholly, confined to the labouring classes, and to the districts which they inhabited, while among the wealthy and middle classes of society it was comparatively seldom met with ; and when it did occur, was not spread by contagion through all the inmates of the family, as was usually the case among the families of the poor, but was confined to a single individual."1 These results, as stated by the above-mentioned authors, agree, we are convinced, with those which have been made in almost every other place. This remark- able difference, in the two classes of persons referred to, must be owing chiefly to the wide diversity of circumstances in which they are placed ; and approximates very closely to the difference which exists between a crowded and consequently an ill-ventilated hos- pital, and one which is limited to a small number of patients with thorough ventilation. The lower classes in large cities generally live in dirty, ill-ventilated houses, and are often filthy in their per- sons ; while the better ranks live in more airy situations, have larger houses, and are more attentive to cleanliness in their per- sons and domestic habits; hence the effluvium which issues from a typhus patient, in the first-mentioned situations, cannot be 'carried off so readily, or diluted to the same extent with atmospheric air, as in the second. But it may be said by the opponents of typhoid contagion, that small-pox, measles, and scarlet fever, more fre- quently spread in the families of the better ranks than typhus; and why is ventilation and dilution not effectual in these cases? In answer to this objection, it may be stated, that these three last- mentioned diseases are not equally contagious, and that scarlet fever, particularly when it is not epidemic, is often confined to one person in a family; whereas small-pox, in the majority of instances, affects the greater number of unprotected persons, adults as well as children. M. Rayer states that "scarlatina is contagious, but to a less degree than measles. It affects chiefly children and young persons, more rarely adults. Every individual is not, to the same degree, apt to be affected with scarlatina, and every condition is not equally proper for its development. It attacks females more 1 Cowan's Vital Statistics of Glasgow, p. 34. 3—e 2 dav 18 DAVIDSON ON THE CAUSES OF FEVER. readily than males; and some individuals, after having been exposed, in vain, during many days to the contagion of this disease, have been seized after the lapse of some time, in consequence of a simple communication with persons who had visited patients affected with this exanthema."1 Dr. Bateman states that adults are not very susceptible of the disease (scarlet fever), and that many medical practitioners who have attended great number of patients affected with it, have never experienced its effects.2 Dr. Mason Good observes that " nothing is more common than for a sporadic case of rosalia (scarlatina) to occur in a family with- out communication of itself to the surrounding children, although no pains may have been taken to keep them separate; while a few months afterwards it may possibly be received from a neighbour's house, merely by an accidental visit for a few minutes. In the one case, there was no predisposition in the habit to receive the com- plaint ; in the other, the altered state of the atmosphere has, per- haps, produced such a predisposition in a very high degree, and prepared the way for the disease to become a very general epidemic. What this peculiar state of the atmosphere is, has not been very accurately ascertained."8 Now, although it be granted that clean- liness and ventilation have somewhat less effect in preventing the spread of small-pox, measles, and scarlet fever, than in checking the progress of typhus; it has been shown by the above quotations that these diseases differ from one another in points equally mate- rial. It follows, therefore, that scarlet fever is regulated by a law similar to that of typhus, in being little contagious under certain circumstances; and that though cleanliness and ventilation may not prove an antidote equally efficacious to the contagion of small- pox, measles, and scarlet fever, as to that of typhus, yet to exclude the latter from the class of contagious fevers from this circumstance, would involve also the exclusion of scarlatina for an equally strong reason. In reasoning upon this subject, it does not seem difficult to conceive that one species of effluvium may be harmless, if diluted with a certain proportion of atmospheric air, while another may retain its virulency under similar circumstances; or that one species of effluvium may adhere with tenacity to every kind of clothing, while another is absorbed most readily by filthy gar- ments, or by the deposits which are formed on the skin of an un- cleanly person. We are in possession of no experiments which tend to prove such an opinion; but there is one analogy which will occur to every medical practitioner in vaccination. It is well known that if too much blood be drawn during the process of vac- cination, the effect is very frequently prevented; and this is always explained on the principle, that the vaccine virus is diluted too 1 Rayer des Maladies de la Peau, torn. i. p. 63. 2 Bateman on Cutaneous Diseases, p. 70. 8 Good's Study of Medicine by Cooper, vol. iii. p. 19. DAVIDSON ON THE CAUSES OF FEVER. 19 much with the blood, as the same result follows when it is mixed with water. We have many analogies among the gases, such as carbonic acid, carburetted hydrogen, &c, to prove not only that when diluted to a certain extent with atmospheric air they may be respired with safety, but that each gas has its own peculiar law respecting the requisite proportion of dilution that is required for that purpose. The majority of French physicians are of opinion that typhoid fever is not contagious, and this belief was almost universal until M. Bretonneau published a contrary opinion. The following quo- tation from M. Chomel will perhaps account, to a certain extent, for the opinions of the French physicians on this subject:—"An- other circumstance contributes with us to render the transmission of a contagious malady difficult, particularly the typhoid disease, that in our hospitals every thing connected with cleanliness and ventilation is in the most perfect condition, and that the typhoid patients are never united, either in the same establishment or in the same ward, while their number is always very small, when compared with the number of those affected with other diseases; so that none of the conditions are present which favour contagion. It is the same with small-pox, and no one disputes its contagious character. In the wards of our hospitals, there are persons fre- quently affected with small-pox, and there are often individuals who have not been vaccinated, or who, not having undergone variola, are susceptible of contracting the disease; yet few in- stances of its transmission are evident. It is also very rare that the transmission of measles or scarlet fever from one subject to another, in the Hopital des Enfans de Paris, can be verified, which even presents in some circumstances the most favourable conditions for the transmission of these diseases."1 At page 98, some tables are given which tend to show the connection of filthy habits with typhus contagion. 2. Typhus generally attacks individuals only once during their lives.—The second law of contagious fevers is that they only affect persons once during their lives. We believe this law to be completely established, and though there are instances of small-pox, measles, and scarlet fever affecting individuals more than once in their lives, yet these may fairly be considered only as exceptions to the general rule. Before bringing forward the facts upon which the claims of typhus to be comprehended under this law may be founded, it is necessary to state that the evidence is by no means so clear and satisfactory as it is in small-pox, measles, and scarlet fever. These three last-mentioned diseases cannot, in the present day, be readily confounded with any other; for their diagnostic marks are very precise and definite; while the several kinds of continued fever have hitherto not been accurately ascertained, and have sometimes 1 Chomel, Lecons de Clinique Medicale, torn. i. p. 321. 20 DAVIDSON ON THE CAUSES OF FEVER. been considered merely as varieties of typhus; hence the difficulty of establishing the application of this law to any one of them. We hope, however, it will appear from the quotations which shall pre- sently be adduced, that the approximation of typhus to this law is so near as to preclude, in all fairness, its exclusion. M. Chomel, after remarking upon the number of persons that are seized more than once with pneumonia, states that "In the typhoid fever, on the contrary, notwithstanding the care with which the patients had always been interrogated on this point, no one, among one hundred and thirty persons who had been received at the Clinique affected with the disease, gave such a statement as could lead to the pre- sumption that he had ever before laboured under it; on the con- trary, most of them asserted that it was the first time they had been ill."1 He elsewhere adds: "We have already stated that the typhoid fever, in ordinary circumstances, affects the same indivi- dual only once. This is the result of all the facts hitherto col- lected. Since we began to make special researches and conclu- sions respecting this disease, no authentic example to the contrary has been observed, although the number of cases which are observed be very considerable, and examples of its return ought to be met with, if the malady were susceptible of being reproduced many times in the same person." In interrogating our patients, we have always taken care to turn their attention from this quarter, but they have never answered in such a manner as to induce us to believe that they had laboured under the same disease; and after all, though some contrary facts should be met with in so frequent a malady, these exceptions, which are little numerous, are nothing extraordinary, and do not overthrow the species of law which has been announced. Small- pox, scarlet fever, measles, which most generally attack the same individual only once, sometimes return, especially during epidemics of these diseases ; it will not be more astonishing if some examples of a return of the typhoid affection be met with. This circum- stance is, then, a very important fact, for there are only a small number of diseases that attack the same individual only once, and amongst these maladies, there is none which is not evidently con- tagious ; the typhoid fever will, then, be the only exception to this kind of law, if it be not contagious like the diseases with which it has this important point of agreement. In the mean time we ought to observe that, though all the diseases which attack the same per- son only once are contagious, it does not follow that all those that are transmitted from one individual to another attack only once, many among them, as syphilis and the itch, are reproduced indefi- nitely."2 Dr. Lombard, of Geneva, when describing the difference between the continental and British typhus, states that "in one remarkable 1 Chomel, Lecons de Clinique Medicale, torn. i. p. 309. ■Ibid, p. 333. DAVIDSON ON THE CAUSES OF'FEVER. 21 point, however, I believe they agree, I mean the fact that no one is known, or at least is very rarely known, to have the eruptive typhus twice. With us such instances are scarcely if ever met with, and 1 am informed that with you a person once attacked with typhus, attended with the measles like eruption, may safely calcu- late upon immunity from the disease for the future."1 Dr. Perry, of Glasgow, states as one of his conclusions respect- ing typhus fever, that "contagious typhus is an exanthematous disease, and, like smallpox, measles, and scarlet fever, during its course produces some change on the system, by which the indi- vidual having once undergone the disease is (as a general rule) secured against a second attack, and may with impunity expose himself to the contagion of typhus, if he continues to reside in the same country in which he previously had the disease. In those cases which are exceptions to the general rule, the disease appears in a mild and modified form, the crisis taking place on the seventh, ninth, or eleventh day." The same author states that this conclu- sion as well as the others in his paper are " the result of careful observation in upwards of 4000 cases."2 Drs. Barker and Cheyne, who had the most extensive opportunities of ascertaining the his- tory of typhus, seem to entertain opinions similar to those already quoted. They state that "at the hospital in Cork street, only one physician and the apothecary had an attack of fever; but then most of the physicians of the establishment had laboured under that dis- ease on some former occasion previous to the appearance of the epidemic."3 Dr. Cowan, as already quoted, states that all the gen- tlemen who have acted as clerks in the Fever Hospital for many years past have been attacked with fever unless they had it previ- ously to their election. Hildenbrand's opinion on this subject is of a more modified kind. He states that " the miasma of typhus, after having produced the fever, destroys almost always for a certain time the susceptibility to a similar contagion ; nevertheless, it destroys it rarely for the whole of life, as does smallpox, measles, &c. It has, however, under this resemblance some analogy with the virus of these dis- eases, whilst on the contrary it totally differs from the syphilitic virus, which when once introduced into the human body, always favours more and more a similar contagion."* The following table shows the answers to questions which were carefully put to patients who were admitted into the Glasgow Fever Hospital from November 1st, 1838, to November 1st, 1839. It includes the whole of the patients affected with eruptive typhus, from whom answers were obtained relative to any former affection with fever, as evidence from decided cases only could be made available in the elucidation of this point: 1 Dublin Journal of Medical Science, vol. x. p. 22. 2 Edinb. Med. and Surgical Journal, vol. xlv. p. 67. 8 Barker and Cheyne on Fever, vol. i. p. 135. 4 Hildenbrand, de Typhus eontagieux, par J. C. Gasc, p. 118. 22 DAVIDSON ON THE CAUSES OF FEVER. Not previously affected . . . Previously affected .... Males. Females. Total. 284 33 251 41 535 74 609 This table shows that out of 609 eruptive or decided cases of typhus there were only 74 persons who stated that they had pre- viously laboured under fever. This part of the evidence may be reckoned positive; for individuals of all intellectual capacities re- member a remarkable circumstance of this kind. On the other hand, the evidence respecting the nature of the former fever or affection is the converse of this; for only in a very few cases can it be correctly ascertained ; and when we take into account the vari- ous diseases which are confounded with typhus (as shall be after- wards shown,) such as bronchitis, pneumonia, pleurisy, intestinal affections, febriculous or short fevers, and the numerous ailments of childhood, this small number can be satisfactorily accounted for. It appears, therefore, that the evidence which can be produced to bear on this point, although not very extensive, decidedly supports the opinion that eruptive typhus fever affects individuals as a gene- ral rule only once in their lives ; and it is to a considerable extent corroborative of this opinion, that almost all the clerks and nurses of the Glasgow Fever Hospital for the last six or seven years have had typhus characterised by the eruption, and not one of them, as far as we have been able to learn, have ever had it since; while almost all of them consider themselves now perfectly secure against a second attack, although constantly exposed to the effluvia arising from fever patients. 3. Typhus is characterised by an exanthematous eruption. The third characteristic of the contagious exanthemata is an erup- tion which has a regular rise, progress, and decline. The exan- thematous eruption or rash which is peculiar to typhus fever has only been accurately attended to within these few years as a diag- nostic symptom. It was, however, noticed by Rogers, in the fever which prevailed in Ireland during the year* 1731, and one of the characteristic symptoms is described as "a universal efflorescence of petechia? j"1 also by Huxham in 1734-5, Sir John Pringle in 1750, &c. No particular conclusion can be drawn from these authors' ac- count of it; but when taken along with their general description of the disease, the opinion is corroborated that it was the very same affection that is so characterised at the present day. Hildenbrand described it in 1806 more particularly than any previous author. He states that it makes its appearance about the fourth day of the disease on the breast, loins, back, thighs, and arms, as being more warm, but sometimes on the face; that it is so much more abun- 1 Barker and Cheyne on Fever, vol. i. p. 4. DAVIDSON ON THE CAUSES OF FEVER. 23 dant as the eyes are red. He also remarks that petechia? may exist with or without the eruption, are not indispensable phenomena, and are only developed in certain conditions. He farther observes that the exantheme is sometimes not present in those cases of typhus which are irregular in their progress.1 The typhoid erup- tion was also a very general characteristic of the epidemic fever which prevailed in Ireland during the years 1817-18-19. Dr. Bracken makes the following statement: "Of about 250 cases which fell under my care in November and December of that year, the majority had eruptions of spots of various appearance as to size, shape, and colour. They were generally of a diffused appearance, gradually shading off, and insensibly disappearing, and of the size of a grain of hemp-seed, but sometimes much larger or much smaller. The distinct, well-defined petechia? were frequently seen of a bright brown or purple colour. The shoulders seemed to be more frequently affected by these eruptions, but the whole surface of the body was often covered by them."2 Drs. Barker and Cheyne give the following account of the eruption, as deduced from reports received from several parts of Munster: "As the disease advanced it was observed in most or all parts of the province that eruptions of different kinds, either closely allied to or varieties of those termed petechial, very generally accompanied it. In some instances the eruption was papular, or a motley appearance of the skin, or a rash somewhat resembling measles showed itself. At Cork, Dr. M. Barry remarked that in the species of fever which he terms syno- chus, petechia? seldom occurred earlier than the fourth or fifth day; but his observation, if it does not express it directly, at least im- plies that their occurrence was frequent. They were generally of a bright red colour, sometimes small, at other times large. He did not consider them dangerous, nor find it necessary to abstain from those measures of depletion which were useful when high excite- ment prevailed. In a communication from Clonmell, Dr. Fitz- gerald states that petechia? occurred in four cases out of five. At Listowel, petechia was so common that Dr. O'Connell did not see six cases of fever unattended by a petechial eruption, which often appeared early in the disease." In the account of Connaught, the same authors state that "an early eruption of petechia?, which were often to be observed on the third or fourth day or even earlier, and were visible for four or five days, was a general symptom of the disease ; when petechia? appeared thus early, they were not indicative of any malignancy." In the report for Ulster, it is stated that petechial eruptions were very common and that they occurred early. For Leinster, the same reporters state that one physician observed the petechia? in seven cases out often, some thought them more general than they had been on any former occasion, and others represented them as universal. They appeared on the third, 1 Hildenbrand, de Typhus contagieux, par J. C. Gasc, p. 53-4. 1 Barker and Cheyne on Fever, vol. ii. p. 231. 24 DAVIDSON ON THE CAUSES OF FEVER. fourth, or fifth days, continued visible for four or five days, and were often remarked in the mildest cases.1 The typhoid eruption, however, excited very little attention among the authors who wrote upon the epidemic that prevailed in Britain about the same period as in Ireland; and even up to a much later period it is only noticed in a cursory manner in our treatises on fever, and not as a diagnostic mark of great value. Dr. Alison in 1827 described it as a very frequent symptom of the epidemic which prevailed in Edinburgh about that period, occurring in a majority of the cases, and remarked that these eruptive fevers formed the connecting link between continued fever and the con- tagious exanthemata.3 M. Louis, who published his admirable work on gastro-enteritis or typhoid fever in 1829, states that " he has observed this eruption in twenty-six out of thirty-five cases, where it has been searched after, without saying that it was not present in some others ; many of the persons in whom it was present had come to the hospital after the twenty-fourth day of the disease, at a period when the spots had perhaps disappeared."3 M. Chomel gives the following excellent description of the typhoid eruption : "Usually from the seventh to the ninth day the eruption peculiar to typhoid fever makes its appearance, which consists in minute rose-red spots, dis- appearing on pressure from half a line to two lines in diameter, of a circular form, without elevation or scarcely raised above the level of the skin, dispersed over the abdomen, sometimes on the chest, less frequently on the thighs, the arms, and forearms. These little spots are so much the more distinct as the skin is white; in persons who have brown skins they are sometimes distinguished with difficulty. Their number cannot be determined because they are not all equally apparent; but in order to furnish a character- istic of the typhoid affection they ought at least to be from fifteen to twenty. When there are only two or three, no value can be attached to their presence. The eruption does not make its ap- pearance on all points at once ; often, after having noticed for three or four days some rose-coloured spots upon the abdomen, but in too small number to be considered as important, they are found all at once very numerous upon the chest and belly, sometimes upon the thighs, the arms, the back, and even the face, though very rarely. Its duration is not always the same ; in some cases, after two or three days, there is no vestige of it; at other times it persists during twelve or fifteen : but in the latter case it consists of many succes- sive eruptions: for each rose-coloured spot is usually visible for three or four days only, and sometimes less ; and at the end of this time if disappears altogether, after having attained a colour less vivid. These spots present, at most, a slight elevation on the sur- 1 Barker and Cheyne on Fever, vol. i. pp. 426, 454, 465, and 483. 8 Edinb. Med. and Surgical Journal, vol. xxviii. 3 Louis, de Gastro-Enterite, torn. ii. p. 231. DAVIDSON ON THE CAUSES OF FEVER. 25 face of the skin, but they never have a conical form or vesicles at their apex. They rarely appear before the eighth day after the invasion of the disease. The following are the results of observa- tions collected in our wards during the years 1830-1-2. Among seventy cases of typhoid fever, where the presence or absence of rose-coloured lenticular spots was carefully established, in sixteen cases, at no period of the disease could traces of this eruption be found ; from which it may be inferred that in about one fourth of the persons seized with the typhoid affection this eruption is want- ing."1 Chomel found that among fifty-four cases none presented the eruption before the sixth day, and in two it appeared after the thirty-sixth. This, he states, is confirmed by the observation of M. Louis, which were made on a much larger number of patients. He attaches great value to the eruption, as a diagnostic mark of typhoid fever, as it is as rare in other acute diseases as it is com- mon in this. Dr. Roupell states that in St. Bartholomew's Hospital, London, the eruption in typhus occurs in seventy out of every 100 cases.2 Dr. West, in his account of the typhus exanthematicus as observed in St. Bartholomew's Hospital, states that " forty-two cases pre- sented the peculiar measle-like eruption described by so many authors, which in all those cases in which I have been able accu- rately to note the date of its appearance, first showed itself from the sixth to the eighth day, generally on the former. It appeared in one instance on the fourth and another time on the fifth day; but I never saw it make its first appearance after the eighth day, though it was still visible on several patients admitted on the fourteenth, and on three who came to the hospital on the twenty-first day of the affection. Of the eighteen cases in which no eruption was observed, five only were admitted before the eighth day of the dis- ease; it is, therefore, very probable that the eruption had existed in some of these patients but had disappeared before their admis- sion."3 Dr. Cowan has investigated the frequency of the eruption in the Glasgow Fever Hospital on upwards of 2000 cases, during the year 1835-6 ; and his results are the following: " At the close of the year, in 76*16 per cent, of the males, and 71-77 of the females, the typhoid eruption had occurred, giving as an average of the whole cases 7399 out of every 100 admitted."4 Dr. Craigie found the typhoid eruption only in seventy-nine among 169 cases in the Edinburgh Royal Infirmary;5 while Dr. Henderson discovered it in 108 cases out of 130 in the same insti- tution at a subsequent period.6 1 Chomel, Legons de Clinique Medicale, torn. i. p. 18. 2Roupell on Typhus, p. 35, 1833. 'Edinburgh Medical and Surgical Journal, July, 1838, p. 140. 4 Cowan's Vital Statistics of Glasgow, p. 26. 'Edinburgh Medical and Surgical Journal, vol. xxvii. p. 301. 4 Ibid. October, 1839, p. 437. 26 DAVIDSON ON THE CAUSES OF FEVER. In the Glasgow Fever Hospital, from May 1st to Nov. 1st, 1839, during which time the presence or absence of eruption was care- fully noted, the proportion was as follows: Cases without Eruption or doubtful Males. Females. Total. 224 130 217 120 441 250 691 This table includes every case, with the exception of smallpox, measles, hooping-cough) and scarlet fever. Dr. Peebles, in 1835, gave a very minute and excellent account of exanthematous typhus, and states, as the result of a minute inquiry into the subject in Great Britain and on the continent, that " he has found the eruption as constant as any exanthema of other eruptive diseases."1 It appears, therefore, that the eruption is present generally in from 70 to 75 out of every 100 patients that are admitted into fever hospitals in this country as well as in France. It must be well known, however, to every hospital physician, that cases are fre- quently admitted as continued fever, that are found, on examina- tion, to be other diseases, and which are usually included in the total enumeration; but this point shall be further illustrated in another part of the essay. It is also well known that many cases of fever are admitted at a very late stage of the disease, as may be proved by statistical tables and also from the great number of deaths that occur on the first, second, and third days after admission; hence it is extremely probable that the eruption has disappeared in a certain proportion of those who have the other decided symptoms of typhus. There is one fact, however, which powerfully supports the opinion that contagious typhus, in the great majority of cases, particularly in adults, is attended with the eruption, namely, that almost all the instances of fever which have occurred during the last six or seven years among the physicians, clerks, nurses, to gj 1—I ■- > 13 S Oh 5 1 2 1 4 Febricula . . 2 ... 1 3 Intestinal Fever 1 2 3 Pneumonia . 1 i 2 12 32 DAVIDSON ON THE CAUSES OF FEVER. It appears from these tables that among the cases of typhus there was not'a single relapse into the same febrile state, characterised by a new eruption and the other distinctive marks of this disease; but on the contrary that all the secondary affections were well marked local diseases. It is also shown that two cases of febricula and one of intestinal fever were affected with typhus during their residence in the hospital; and it is probable that more of such cases would have been infected had not the precaution been adopted of dismiss- ing them as early as possible. In concluding our remarks upon relapses, we shall make the fol- lowing quotation from Drs. Barker and Cheyne's work, in order to show that one of the most powerful facts in favour of the doctrine of relapses may he explained by the theory we have adopted. These authors state that " as the epidemic advanced and particu- larly in its latter stages, relapses became very common, insomuch that a very large proportion of those who had been attacked suffered a relapse, and with many this happened several times. ... It was remarked at Roscrea that the more early the crises occurred the greater was the probability of relapse. This observation will apply to every part of this province, for as the epidemic fever approached to a close, a fever of short duration, continuing for about five days, extremely mild and rarely proving mortal, became very frequent, and at this time the tendency to relapse was most observable. On the contrary, after fever of long continuance, it rarely happened that relapse took place."1 .... The same authors in their medical account of fever in Connaught, state that " relapses were so rare at the commencement of the epidemic that Dr. Veitch, Physician to the County Infirmary in Galway, in his letter of the 6th September, 1817, says that he had not observed one case of relapse out of some hundred cases of fever." In de- scribing the disease as it occurred among the upper ranks in Gal- way, they state that " petechia? were universal, insomuch that scarcely a case occurred without them."2 The inferences which may be deduced from these quotations are, 1st. That these short or five-day fevers were either not typhus or their convalescence was only a remission of the disease; for we are not aware of any writer on this subject who describes it as ter- minating so early. 2d. Very few of those which were protracted, or which continued to the end of the second or third week, relapsed, which is about the average period for the duration of typhus. 3d. That in Galway, where petechias or the typhoid eruption were almost universal, showing the disease to be typhus, not a single case of relapse occurred out of some hundred cases. 1 Barker and Cheyne on Fever, vol. i. p. 438. ' Ibid. p. 455. DAVIDSON ON THE CAUSES OF FEVER. 33 Sect. III.—Sources of Continued Fevers, not Typhoid. Pneumonia, pleuritis, peritonis, bronchitis, and modifications of these affections are not unfrequently confounded with continued fever, being admitted to fever hospitals as such; and thus the numerical amount of non-eruptive cases of typhus is often con- siderably increased by the inclusion of these diseases in the list; independent altogether of the two other affections which we are about to describe, and which are generally considered continued fevers, although different from typhus in their prominent features and laws. The first and most prevalent of these two affections has been called febricula, on account of its mildness and short duration, when compared with typhus. The second is prominently accom- panied with derangement of the digestive organs, either in the form of constipation or diarrhoea. Chomel makes the following observa- tions, when treating of the diagnosis of typhoid fever: " In effect, various diseases may present, during the first three or four days, a great resemblance to the typhoid affection. Among the diverse morbid states which may at this period present analogous pheno- mena, we shall find the early symptoms of many eruptive diseases, as smallpox, scarlet fever, and measles; also some catarrhal affec- tions of little intensity: protracted ephemeral fever may be taken for the typhoid inflammatory fever, bilious derangement for bilious fever, exhaustion for the commencement of an adynamic fever, and especially a latent phlegmasia either visceral or venous. . . One of the most important characters of the typhoid affection is the duration of the febrile state. As often as the febrile phenomena which can be attached to any appreciable lesion are prolonged beyond a certain limit, eight or ten days for example, there will be already serious grounds for presuming an alteration of the glands of Peyer; and when a disease terminates at the end of some days, we can always be assured, whatever doubts may have existed as to its nature, that it was different from the typhoid affection; and thus all the morbid states, the duration of which does not extend to the tenth or twelfth day, are distinguished."1 1. Sources of Febricula. This affection generally commences, like typhus and several other febrile affections, with a rigor, at- tended by headach, frequency of pulse, heat of skin, flushed face, thirst, moist tongue, generally more or less coated with a whitish fur, and red at point and edges, more or less constipation of bowels, and in the great majority of cases uncombined with any deter- minate local affection. It is difficult to distinguish this fever from typhus for the first four or five days; but after that the diagnosis may in most cases be made with tolerable accuracy. If the typhoid eruption be present, there can be no doubt what- ever of the nature of the disease; for in Britain this peculiar ' Cliomel, Lecons de Clinique Medicale, torn. i. p. 400. 3—f 3 dav 34 DAVIDSON ON THE CAUSES OF FEVER. efflorescence occurs in no other febrile affection that could be con- founded with typhus ; but in a certain proportion of cases it is not present in the latter disease. In cases of typhus destitute of the eruption, there are frequently, however, other symptoms present, even by the sixth day, which are rarely if at all observed in febri- cula ; such as suffused eyes, delirium, or partial stupor, a dry and brown tongue, a dark or dusky hue of the skin. The frequency of the pulse is also a very important symptom in the diagnosis; for in febricula it is rarely above 100, and it generally continues full or of moderate strength throughout the whole course of the disease; whereas in many cases of typhus, the pulse becomes weak, soft, small, or very compressible, at an early period of the disease, and in most cases is more or less above 100 about the sixth or seventh day. Sometimes this fever terminates in one or two days, being described by some authors under the name of ephemera; but more generally symptoms of amendment appear about the sixth or seventh day, and complete convalescence is established, in the large majority of cases, from the sixth to the tenth day. Deafness and desquamation of the cuticle, both of which are frequent cha- racteristics of typhus, are generally absent in this affection. Again, complete convalescence from typhus rarely occurs in adults before the fifteenth day, and is in a majority of cases much later. In children, however, the crisis of typhus generally appears earlier than in adults; but the febriculous affections to which they are liable are proportionally short, often only one or two days in dura- tion. The statistical facts connected with the minimum and maximum duration of typhus have not been very conclusively determined; for, as we formerly remarked, one class of authors terminate the disease when the stage of convalescence begins, while another class do not consider it terminated until the patient is discharged from the hospital; and this discrepancy is still further increased by not carefully classifying the different febrile affections that are admitted into fever institutions and their corresponding duration. M. Chomel, who seems to have been exceedingly careful in drawing his conclusions only from decided cases of typhoid fever, gives the following statistical account of the duration of the disease, from its commencement to the beginning of convalescence : In I patient on the 8th day after attack. 1 " " 9th " 4 " " 12th " 3 " between 12th and 14th day inclusive. 10 " <: 15th and 16th 15 " « 17th and 20th 14 " '< 21st and 25th " 11 " " 26th and 30th " 8 " " 31st and 40th " 1 " on the 45th. DAVIDSON ON THE CAUSES OF FEVER. 35 "If, however," he adds, " we throw aside the cases in which im- provement has appeared before the fifteenth day, and those in which it has appeared after the thirtieth, which constitute a small number of exceptions, there remains fifty cases out of sixty-eight, that is nearly three fourths, in which this improvement took place, from the fifteenth to the thirtieth day."1 It appears from this table that there were only two out of sixty-eight cases that presented symp- toms of convalescence at the eighth and ninth day, and if we add five or six days for its complete establishment, the disease, even in this fractional proportion of cases, could not be considered as ter- minated before the thirteenth or fourteenth day. This method of calculating the duration of fever, adopted by Chomel and many other authors, is greatly inferior in accuracy to that of marking the patient convalescent when he is actually free of the febrile symptoms, namely, when his pulse is natural, his tongue pretty clean, his sleep tolerably sound, and his appetite moderately good, but still weak, and consequently unable to leave the hospitaf for some days at least. It is quite obvious that the positive character of these four symptoms renders them more fixed, more easily ascertained, and not so likely to be misapprehended as their relative improvement during the first stage of convalescence; and therefore that it is preferable in the determination of this ques- tion. It appears necessary, before presenting our table constructed on this principle, to give one which will show the whole diseases that have been admitted within a certain period into the Glasgow Fever Hospital, namely, from May 1st to November 1st, 1839; as some of our deductions depend upon a fair and impartial consideration of these cases, and as the various statistical points referred to in this section were noted with care. 1 Chomel, Lecons de Clinique Medicale, torn. i. p. 44. 3* 36 DAVIDSON ON THE CAUSES OF FEVER. a g { Typhus,..... Males. Females. Total. 270 276 546 '5 > \ Febricula, .... 32 31 63 ' Gastric or Intestinal Fever, . 8 7 15 O Bronchitis, .... 14 8 22 Pneumonia, .... 15 7 22 Smallpox, . . . . 16 11 27 Measles,..... 3 1 4 Scarlet Fever, 4 4 Hooping-cough, 1 1 2 Hydrocephalus, 1 1 Erysipelas, .... 3 3 Roseola, .... 2 2 Erythema, .... 1 1 Hepatitis, .... ] 1 Apoplexy, .... 1 1 2 Determination of blood to head, 1 1 Intermittent Fever, 1 1 Cynanche Tonsillaris, . 1 1 2 Syphilis, .... 1 1 2 Delirium Tremens, 1 1 Suppuration of Kidneys, 1 1 Phthisis, .... 2 2 Dysentery, .... 2 2 Mania,..... 1 1 368 360 728 As a considerable number of the cases in the above table were not continued fevers, it may be necessary to explain one or two points respecting the admissions into the Glasgow Fever Hospital. The facilities of admission have of late been very great, in conse- quence of there being much more accommodation than was re- quired ; and every case, where there was the slightest suspicion of fever, seems to have been sent to this institution, not only from the city, but from its vicinity to the extent of many miles. It may be supposed that there is a large number classified as bronchitis and pneumonia; but it requires to be stated that in all the cases of the first mentioned disease, there were no typhoid symptoms present, and that only two or three were arranged under this division, whose convalescence extended beyond the tenth day, while the greater number of the pneumonic patients were bled from the arm, and the blood found decidedly buffy. The case marked suppuration of the kidneys was one of peculiar interest. The patient had been delivered of a child about a fort- night before her admission, and was at this latter period found quite comatose, but there were none of the peculiar symptoms of typhus present. The inspection, however, cleared up any doubt that existed as to the nature of the affection, for both kidneys con- tained numerous small abscesses throughout their whole texture, DAVIDSON ON THE CAUSES OF FEVER. 37 there was pus in both pelves, in the ureters, and bladders, but no urine in the latter organ. We shall next present a table, showing the maximum of the pulse and the period of complete convalescence in 181 cases of eruptive typhus, and in thirty cases of febricula, that were admitted into the Glasgow Fever Hospital from May 1st to November 1st, 1839, and it includes the whole that were admitted within that period, except two or three, whose convalescence and pulse were not noted, and those that were omitted for reasons to be presently stated. Table of the Maximum Frequency of the Pulse in 181 Cases of Eruptive Typhus. Males. Females. Maximum fre-quency of pulse. No. of Cases. Maximum fre-quency of pulse. No. of Cases. 86 96 100 104 106 108 110 112 116 118 120 124 128 130 5 20 8 4 3 15 1 4 4 1 18 5 1 1 90 96 98 100 104 108 110 112 116 120 124 130 134 140 12 1 3 5 j 23 1 3 3 17 7 10 2 4 91=181 Average maximum of pulse in Males = 107.5. " " Females = 114.1. " " Males and Females = 110.8. The five cases in which the pulse is marked 86 were admitted on the seventh, ninth, eleventh, fourteenth, and twenty-first days of the disease, so that it is probable that partial convalescence had commenced at the time the pulse was noted. 38 DAVIDSON ON THE CAUSES OF FEVER. Table showing the Day of the Disease on which complete Convalescence was established in 181 cases of Eruptive Typhus. MALES. Females. Day of disease. [ No. of Cases. Day of disease. No. of Cases. 12th ; 1 13th 2 13 4 14 7 14 2 15 11 15 9 16 3 16 9 17 9 17 : 9 18 10 18 i 6 19 6 19 7 20 10 20 3 21 3 21 10 22 5 22 1 8 23 2 23 2 24 3 24 6 25 1 25 2 • 27 4 26 4 28 1 27 4 29 3 28 1 30 2 29 3 32 1 34 4 36 1 44 1 54 2 90 91=lSltot. Average convalescence in Males = 19.7 days.1 " Females = 21.3 davs. " " da ys in Males and Females = 20.5. Every case below twenty years of age has been excluded, be- cause the maximum of the pulse varies more from childhood to adolescence than during any other similar period of life ; and those who died have also been excluded, as the comparison between the pulse and the recovery would not be uniform in the two diseases and as the average maximum of the pulse of those cases which ter- minated fatally was greater than that of those who recovered We have taken the eruptive cases of typhus only by which to illustrate the law of convalescence and frequency of the pulse • in order to prevent any doubt as to the nature of the fever from which the conclusion is drawn, and because they constitute the large ma- jority of fever patients. But it may be said that though the non- ' D^Hen^er-S°lnuta1tes th-at he has seen instances of convalescence on the seventh and eighth days, in which the eruption had existed; but it is not 'fjrZ-l^What st^tof co^alescence the calculation was made, and Set 1839 P43rS PaUenlS- Edinbu'§h Me<*. a»d Surg. Jou'rnal, DAVIDSON ON THE CAUSES OF FEVER. 39 eruptive cases constitute a small or perhaps only an exceptional proportion of the whole number, they may not follow the same law as the majority, but may be milder, and that the severity of the cases is in proportion to the amount of eruption. Dr. Henderson supports this opinion, which is founded on the examination of about 200 cases in the Edinburgh Infirmary. We can so far support the author of this paper in regard to the general severity of the cases attended with a copious eruption; but certainly there is no uniform proportion between the two, for we have frequently met with mild cases of typhus in which there existed a copious eruption, and oc- casionally with some which terminated fatally when there were only a small number of spots. Indeed, reasoning by analogy from scarlet fever, to which typhus has most resemblance in the irregu- larity of its eruption, we should be led to infer that the intensity of the symptoms would not probably correspond uniformly with the copiousness of the eruption ; for cases of scarlet fever have often been found very malignant during some epidemics, although not characterised by any exanthematous eruption, or by one which was only extremely indistinct or evanescent. There seems to be, therefore, no valid reason why the law of typhus respecting complete convalescence and the frequency of the pulse should not be deduced from the eruptive cases, as they con- stitute, at least, about three fourths of the whole number, and as there is no uniform proportion between the amount of the eruption and the severity of the symptoms. Table of the Maximum Frequency of the Pulse in 30 cases of Febricula. Males. Females. Maximum fre-quency of pulse. No. of Cases. Maximum fre-quency of pulse. No. of Cases. 68 2 72 1 72 7 74 1 76 76 1 82 '84 3 84 88 1 86 90 2 92 92 2 96 1 100 3 104 1 i— — 14 16=30 tot. Average maximum of pulse = = 82.8 in Males and Females. 40 DAVIDSON ON THE CAUSES OF FEVER. Table, showing the Day of Disease on which complete convalescence was established in 30 Cases of Febricula. Males. FtMALES. Day of disease. No. of Cases. Day of disease. No. of Cases. —y— 4th 1 3d 7 3 4 1 8 3 5 1 9 2 6 1 10 5 7 2 8 3 9 3 10 4 14 16=30 tot. Average convalescence z= : 8 days in Males and Females. These tables show that, in 181 cases of eruptive typhus occurring in adults, the maximum frequency of the pulse was not below 96, except in five cases; that in about three fourths it was 108 and upwards, and that the average maximum of the whole was 110.8. They also show that only one case of typhus was convalescent on the twelfth, and six on the thirteenth day of the disease out of this number ; and that the average convalescence of the whole was 20.5 days. Contrast this with febricula, in which out of thirty cases the pulse did not exceed 100, except in one patient, in whom it was 104; and the average maximum of the pulse for the whole was only 82.8. The convalescence in any of these cases of febricula did not exceed the tenth day, and their average convalescence was eight days. Are there, then, reasons for maintaining the opinion that these short and mild fevers are specifically different from typhus, in opposition to that of Bateman and many eminent au- thors? We think there are ; for if diseases are to be discriminated by a difference of laws and phenomena, there is certainly in these two affections a wide distinction in their symptoms, and also a dis- tinct line of separation between them as regards the period of their duration and the frequency of the pulse. This view is supported by the fact that febriculous patients have been frequently affected with typhus during their convalescence in the Glasgow Fever Hospital, which cannot be satisfactorily ex- plained on any other principle than that these two affections are different in their nature. The causes which are generally assigned for febricula also tend to support its disjunction from typhus'; for although they have not been sufficiently investigated, yet there is an approximation to something like a proof, that exposure to cold is more frequently an antecedent to this affection than it is to typhus. The following table shows the causes that were assigned for the following cases of febricula: Cold. Uncertain. Contagion. Total. 22 28 10 = 60 DAVIDSON ON THE CAUSES OF FEVER. 41 This result tends to support the popular belief and that of many medical practitioners, that there is a short fever which has some- times been called "a cold fever," although not necessarily attended by a cough or other pectoral complaint. It is not probable that this affection is contagious, for though more than one in a family sometimes become affected, this is not generally the case, as in typhus among the lower classes ; and it is rare that more than one person from the same house has been ad- mitted for this disease into the Fever Hospital. Besides, the fact formerly stated respecting the almost uniformly typhoid and exan- thematous character of the disease in the Glasgow Fever Hospital, when nurses and hospital attendants became affected, has a ten- dency to support this belief; for cases of febricula are always found associated with typhus in every institution of this kind, when there is no particular restriction respecting admission; and if it were contagious, it is probable that some of the attendants would have been affected with it. And though these short and mild fevers are not generally described and classified separately as to their pheno- mena and laws, there is abundant evidence existing in the writings of our British and Irish authors to prove that they constitute a greater or less proportion of the fever cases of Great Britain and Ireland. It does not appear to be confined, like typhus when not epidemic, to particular localities, such as large towns, &c, and in all probability it is the most common sporadic fever met with in many country districts. It seems also to be capable of attacking the same individual more than once during his life ; and we have in a number of instances attended the same individual within a few years under two different attacks, both having the same cha- racteristics of mildness and shortness. If this view be adopted, it may account to a certain extent for the statements that typhus fever has often been known to affect a person more than once during his life ; the one fever being confounded with the other. We have no facts sufficiently conclusive to bring forward re- specting its mortality ; but undoubtedly it is very small, unless complicated with a particular local affection : and when a disease which originally has all the characters of febricula becomes pro- tracted, the diagnosis becomes so obscure that any deductions drawn from it are very questionable. If the analysis of the cases admitted into the Glasgow Fever Hospital during the six months already specified be granted, it will tend to reduce the number of those without eruption very consider- ably. It is stated at page 26 that there were 250 cases withput eruption, and 441 in whom this exantheme was observed. Now among these 250 cases there were 145 other affections than typhus, which, being deducted from 250, leave as those really non-eruptive 105, being above 80 per cent, of eruptive cases. But the number of those cases without eruption might be still farther reduced ; for a portion of them were admitted after the tenth day of the disease, when it is presumable that the exantheme might have disappeared, 42 DAVIDSON ON THE CAUSES OF FEVER. and some of them were verging on convalescence; so that even during the non-epidemic prevalence of typhus, when other febrile affections bear to it a larger proportion than when it is extensively diffused, the number without eruption is not very great; and this fact may account for the opinion which is held by some authors and by many medical practitioners that the exantheme is chiefly characteristic of typhus during the prevalence of an epidemic. 2. Sources of Gastric or Intestinal Fever.—This febrile affec- tion is very often of an ephemeral kind, lasting only two or three days, and hence it is not frequently met with in hospital practice. Sometimes it results from excesses in eating and drinking, which have been repeated in rapid succession ; occasionally it is caused by a single indulgence in some aliment difficult of digestion. Per- sons who have feeble or dyspeptic digestive organs, particularly if the bowels be constipated, are very liable to this affection if their habits be irregular. The person attacked generally feels a kind of malaise for some days previous to the rigour which often ushers in the febrile symptoms ; the pulse is sometimes extremely rapid, the skin hot, the tongue is coated with a thick white fur, and there is frequently nausea and an uneasy feeling in the abdomen, which is more or less tumid. The bowels are always either constipated or there is diarrhoea, and when the latter symptom is present, even when the stools are feculent, there is very generally reason to sus- pect, at least at the commencement of the disease, the existence of solid excrementitious matter in the cells of the colon. This affec- tion is sometimes suddenly terminated by a copious perspiration ; but more generally, not until the bowels have been freely unloaded of their feculent contents ; and we have repeatedly met with cases of obstinate constipation, in which the febrile symptoms did not completely subside for six or eight days. In many cases it may be distinguished from typhus at the com- mencement by ascertaining the antecedent circumstances of the patient, and by the state of his bowels and abdomen. When the diagnosis is doubtful during the progress of the affection, its short duration in the great majority of cases must necessarily distinguish it from typhus. In some instances, however, particularly when diarrhoea is present, the attack is prolonged for a week or two, and sometimes for two or three weeks. In some of these cases there is a tendency to peritonitis, while in others there is reason to suspect some enlargement or ulceration of the glands of the intestines. We are quite aware that such cases, which are not of frequent occur- rence, might be called typhus fever without eruption; and in the present state of our diagnostic means this question cannot be solved in a satisfactory manner; but we hope that future investigators will be able to define a line by which they may be distinguished. That intestinal fevers, even those of a protracted nature, are spe- cifically different from typhus may be deduced from the fact that repeated instances have occurred of such patients being affected with eruptive typhus during their convalescence in the fever hos- DAVIDSON ON THE CAUSES OF FEVER. 43 pital, and a case of this kind is mentioned in the table of secondary diseases at page 31. Dr. Lombard, of Geneva, in a recent pub- lication, maintains the opinion that there is a bilious fever which is quite distinct from the typhoid fever; but at the same time ac- knowledges the extreme difficulty of the diagnosis. He states that : Medical Histories, vol. i. On New Contagions. 1 Walker's gatherings from Grave-yards, p. 124. 3 On Malaria. London Medical Gazette,—vol. iii. new series. 4__f 5 hudson 146 HUDSON ON THE POISON OF FEVER. the year, may lie latent until the conclusion of a continued fever received many weeks later. 3. This power of generating different diseases, is alleged of those sources in particular which contain a variety of organic matters, and which are in a state of constant change from the superaddition of new materials or from atmospheric changes—such are sewers, the banks of rivers, &c.—and it is to these that the great body of evidence, as to the frequent production of fever, applies, and not to the regular, uniform, and spontaneous decomposition of any single portion of animal matter, however great its bulk.1 Sect. II.—In order to obviate the objections urged against the evidence of the frequent occurrence of fever from malarial sources,— namely, that it has been confounded with contagion, and that, at all events, the evidence proves no more than the frequent co-exist- ence of filth, fever, and poverty. We shall select only a few cases which have occurred under cir- cumstances unfavourable to the supposition of such a cause as contagion, and the histories of which present contrasts to that of contagious fever in some of the following particulars. I. The class of persons affected, not those usually obnoxious to contagious fever unless under circumstances of prolonged exposure. II. Occurring without the presence of any of the aids to contagion and at an opposite season of the year. III. In localities in which contagious fever does not prevail. IV. Spreading in spite of the preventive measures, which are found to check the diffusion of contagious fever. "In great towns," says Christison, "cases are met with during the intervals between epidemics, and in a station of life where epidemic fever in epidemic seasons of the worst kind is seldom witnessed. A fever of this description, tedious in its course, charac- terised by much nervous and muscular depression, without any particular local disturbance, and, especially, without the marked 1 If the subject admitted of an explanation purely hypothetical we might draw an analogy, not destitute of plausibility, between the action of human contagion and putrefaction in this particular; and we might suppose, that as in fever generated spontaneously in the human body, there does not seem to exist any power of communication by infection, so in dead animal matter the product of any single mass of spontaneous putrefaction is not a fever poison, but that this is generated by the exposure of fresh dead organic mat- ter to the contagion of the former. For this hypothesis to be consistent with the facts, the following should be the various consequences of exposure to putrefactive decomposition:— 1. From exposure to a single mass of animal matter undergoing spontane- ous putrefaction—no fever. 2. From exposure to the emanations from substances added to the former disease, varying in intensity in proportion as circumstances were more or less favourable to rapid communication of the "contagion of decay" from decomposing to recent organic matter. 3. From successive exposure of a number of individuals to successive ad- ditions of organic matter, (under above circumstances,) a number of cases of disease. HUDSON ON THE POISON OF FEVER. 147 disorder of the functions of the brain which distinguishes most cases of epidemic typhus and synochus, was so prevalent among the better ranks in certain streets of Edinburgh some years ago, at a time when fever was not prevalent among the working classes, that a general impression arose among professional people of the existence of some unusual local miasma. A great variety of parallel facts might be referred to—all leading to the general conclusion, that a disease if not identical with, at all events closely resembling, synochus and typhus as described above, may arise without the possibility of tracing it to communication with the sick. A state- ment of this kind acquires great weight in the instance of such a visitation of disease as that just alluded to, which prevailed among people in easy circumstances in a great town." Very similar is the testimony of Dr. Cheyne :—" For several years the fever appeared in families only in solitary instances, or if more than one were affected they were seized nearly at the same time, but it did not extend so as to lead us to think that it propa- gated itself. We were unable to assign the cause of the disease further than that we observed in several houses, in which our patients lay, that fetor which is discoverable when a sewer is choked, and, in some instances, upon enquiry it was found that the sewer leading from the house had been improperly constructed and neglected." . A similar instance of fever, apparently caused by defective sewerage, came under my observation recently in the house of a gentleman of fortune in this county. For a longtime an unpleasant odour had been remarked in several parts of the mansion, more especially near this gentleman's study and in the men servants' sleeping apartment. The poisonous effects of the malaria were first produced in the form of obstinate dysentery in one of the female servants. Then the owner of the mansion was attacked with what he at first supposed was mere biliary derangement, but which rapidly assumed all the characters of severe gastric fever, becoming attended towards the close with purple petechia and terminating fatally on the 11th day. About the same time two men servants were seized with symp- toms of fever. In one it was cut short and in the other it ran its course, ending favourably about the 11th day. Two other persons who came to the house on business (from the neighbourhood) and who remained in it for a few hours, were seized with the same fever, which ran through its course at their own houses but without extending to other individuals. After this lamented occurrence the cause of the effluvium was searched for and found to be a leakage of the soil pipe of one of the water-closets, which had allowed the filth to percolate through the wall and exhale into the atmosphere of the house. This exha- lation was also much favoured by the warm temperature kept up in the house by heated flues. About the months of October and November, 1839,1 was repeat- 148 HUDSON ON THE POISON OF FEVER. edly consulted by the inmates of a large establishment in the neighbourhood of Navan, on account of different forms of gastro- enteric, affection, especially diarrhoea and dysentery. So many instances occurred at intervals, (in some cases of weeks,) and the general resemblance was so great, that I thought they must arise from some local cause, and I expressed a strong suspicion that some source of malaria existed in the house or immediate vicinity. The house itself was large, airy, and commodious, so that our inspection was directed rather to the immediate neighbourhood, and it was thought that the cause had been discovered in an old sewer which had been laid open in the course of some building operations. The closing of this was not, however, attended with the effect of stop- ping the endemic affection, though it gradually ceased after about a dozen people had been attacked. The following spring was re- markably dry, scarcely any rain having fallen for about six weeks; toward the close of this period an effluvium of a very disagreeable nature became perceptible in some parts of the house, and at the same time—within a day of each other—two of the inmates were attacked with exquisitely marked typhus, attended with profuse measly eruption, and in one of the patients with violent delirium. Every circumstance rendered the existence of contagion in either case highly improbable, I might almost say impossible, and on my again expressing my strong conviction that some form of malaria was the cause of the fever, I was informed of the effluvium per- ceived in some of the passages, and also of the fact that in the original construction of the water-closets they had been made to depend for their supply of water upon a cistern of rain water, which, of course, had been for weeks empty during the present spring and preceding autumn. These cases did not spread, and all traces of indisposition were removed by making the required alterations for ensuring a constant supply of water. In the month of October, 1839,1 attended a respectable man who resided in a large and airy mansion, as " care taker," during the absence of the family upon the Continent. His illness had come on slowly and insidiously, but, when I saw him, had all the cha- racters of bad remittent fever, attended with much abdominal con- gestion. This it was attempted to relieve by leeches, &c, but it increased and led afterwards to large evacuations of blood from the bowels. He recovered slowly and with difficulty. At the time I saw him he was lying in the basement story of the house. A few weeks after the return home of the family, the butler was attacked with symptoms of gastro-enterite and slight jaundice. He recovered partially in a few days, but in the course of a week after was suddenly seized with complete loss of muscular power, paleness and coldness of the surface, sickness of stomach, (fee, followed by vomiting of a dark olive fluid, and in two days by large evacuations of tarry blood from the bowels, hiccup, subsultus, &c, while the skin was covered with vibices and black petechiae—some of them of the size of large shot. The fever which followed had no percep- HUDSON ON THE POISON OF FEVER. 149 tible remissions and perfectly accorded with the descriptions of putrid malignant fever by Huxham and others. The striking resemblance of some of the symptoms of this case to that which had occurred in the same place more than a year before, led me to at- tribute both to a common cause and to enquire for the source of the malaria. The following were the facts ascertained :—In a room in the basement story, occupied by the last patient and in which he had latterly sometimes slept, was a sink emptying into a pipe, which communicated at the distance of about ten feet with the main sewer of the house—into which the contents of two water-closets passed. This sewer was very large at its termination and when the wind blew from that direction towards the house, there being no smell trap under the sink, the effluvium of the sewer was carried up into this room and became so insupportable that the patient used to stuff the aperture with a piece of rag when retiring to bed. Upon inquiry I was informed that the first patient had frequently before his illness remarked the same fetid effluvium. It is worthy of remark that the sewer had not been cleaned in the interval be- tween the two cases. The following case, very similar to the last in its nature and origin, I give upon the suspicious authority of an anticontagionist:' " I attended," says Dr. Armstrong,2 "a very respectable tradesman, labouring under a remarkable bad attack of typhus fever. It was such a case as would have been called plague in the time of Syden- ham. He had knotted glands and carbuncles, and black petechias. He was one of four or five individuals who had transacted some business in a nobleman's kitchen ; a filthy fluid had overflowed that kitchen; he was sickened at the time, and in common with all the others had an attack of typhus fever." If we looked about for a large town less liable to contagious fever than others we might probably find it in Birmingham,—yet here endemial causes, of the kind which Dr. Davidson has pronounced inadequate to this effect, have produced fever. A good instance for illustration is found in Dr. Ward's account of an endemic fever, which prevailed in certain localities in Birmingham in the summer of 1837. 3" The river Rea, that separates Birmingham from its suburb Badesley and serves as a cloaca maxima to both, carries its filthy stream onward, partly to turn a mill and partly to fill a mill pond. During the drought which prevailed last year the water was very low in the main stream and mill pond, and the mills not being regularly worked became quite stagnant and offensive. The back stream also became dry and showed its mud banks, that were only occasionally wetted by a flush of the washings of the town after a shower, or by the small surplus accumulated during the cessation 1 See Christison, ut supra. * Lectures by Rix. * Provincial Medical Transactions, vol.6. 150 HUDSON ON THE POISON OF FEVER. of the working of the mills. The exhalations from the half dried mud and putrid water were so disagreeable at night as to nauseate the more delicate inhabitants of the adjoining streets, and soon pro- duce disease in the form of typhoid fever of an infectious (?) charac- ter." He goes on to state that about 50 cases—some fatal—occurred in the immediate vicinity of the stream, and "still lower down the stream, where the water was as black as ink, there were 13 pauper cases in one yard, and many others, both pauper and private, along the same line." That this fever was owing to the state of the stream is proved by the disease being confined to the locality, the small number affected in so large a population as Birmingham, the sea- son of the year, and the exemption of this town from the causes which aid contagion—these are well summed up by Dr. Ward. " There is a difference of nearly 200 feet in the elevation of dif- ferent parts of the town. The streets and the courts or yards in which the mechanics live are wide and airy in general; fuel is cheaper than in any other large town in England ; the water is excellent—and till within the last year there has been but little distress." We have already adduced the effects of seclusion of the sick in proof of the infectiousness of typhus. In the fever arising from endemial sources this measure has no such influence. I was much struck with this fact when making some investigations as to the source of a fever, which prevailed in the summer of 1839 in a ham- let attached to a flax manufactory near this town, from which a considerable number of cases had been sent to hospital in the months of April, May, and June. The object of an examination which I made of the place was to obtain satisfactory instances of contagion, but I soon found that no such evidence was to be pro- cured. For the intervals between the illness of different members of the families were too irregular to admit of communication from one to another. Thus, in, one house the first case sickened on the 2d of April, and the second on the 5th. In another, more than three months intervened between the first and second cases. And in several families in which the first case had been early removed to hospital, the second had sickened before the patient's return. Besides, there was too much cleanliness and comfort: several of the houses had been repeatedly white-washed during the time that the fever was going through the family, and the inmates were all well off—being employed in the neighbouring factory. Several things convinced me that this fever had a malarial origin. The hamlet was built in the form of two parallel streets, terminat- ing in a large open space, in front of which were twelve houses looking northeast. This space had no drainage and was full of shallow pools of black putrescent water, into "which the inmates daily threw cabbage leaves,