Part 41

NAME.--It has been objected to the name "typhoid fever" as a designation for this disease that it tends to perpetuate among the laity the mistaken impression that typhoid fever is only a modified typhus fever, and also that the word typhoid has been generally applied to a condition of system which is common to a great many different diseases, {238} and which is not of necessity present in this. In spite of these objections, and although it must be admitted that they are not without force, I prefer to retain the name typhoid fever, and for the following reasons: 1st. It was the name given to the disease by Louis, to whom we owe the first full and accurate description of it. 2d. It is the name by which it is best known to the profession, not only in this country but abroad. 3d. No other name has been proposed for it which is not quite as much open to criticism. Thus the term enteric fever, originally suggested by the late George B. Wood, and adopted by the London College of Physicians in its Nomenclature of Diseases, is objectionable because it brings into undue prominence the intestinal lesions and implies that they are the cause of the fever. The same objection may be urged against the name "intestinal fever," proposed by Budd. The name "pythogenic fever" rests upon a theory of the disease which has never been proven, and is regarded by most observers as untenable. Under these circumstances even the influence of its distinguished proposer, the late Dr. Murchison, has been insufficient to secure its adoption by the profession at large.

HISTORY.--Certain passages in the writings of Hippocrates have been appealed to by Murchison and other physicians in support of the opinion that typhoid fever was a disease of at least occasional occurrence in ancient times; but, although from the nature of its causes it is probable that it has occurred in all ages and wherever men have congregated in towns and villages, the descriptions given by the Father of Medicine in the passages alluded to are not sufficiently full to render it at all certain that typhoid fever had ever come under his observation. Indeed, there is no author of an earlier date than Spigelius whose writings furnish any positive evidence that he ever met with the disease. Spigelius, however, in spite of the doubt thrown upon his observation by Hirsch, would seem to have had opportunities for examining the bodies of those who had died of it, since he gives an account of several autopsies, in which he says that the small intestine was inflamed and that that part of it next to the cæcum and colon was frequently sphacelated. Panarolus also says that the intestines had the appearance of being cauterized ("apparebant tanquam exusta") in some cases observed by him in Rome a little later in the same century. Willis would certainly appear to have been familiar with two forms of fever, which, from the description he gives of them, could have been nothing else but typhoid and typhus fevers. Sydenham also described a fever in which the prominent symptoms were diarrhoea, vomiting, delirium, a tendency to coma, and epistaxis, and which was distinguishable from the febris pestilens by the absence of a petechial eruption. Baglivi of Rome in the latter part of the seventeenth century described the hæmitritæus of previous writers {239} under the title of febris mesenterica, and maintained that it was always accompanied by and dependent on inflammation of the intestines and enlargement of the mesenteric glands. A similar observation was made soon after by Hoffmann, and by Lancisi in 1718. The latter seems to have fully recognized the characteristics of the eruption, for he says that it consisted of "elevated papules which disappeared completely on pressure." In 1759, Huxham described, under the title "slow, nervous fever," a disease which there can be no doubt was typhoid fever. He moreover pointed out very clearly the distinctions between this disease and another to which he gave the name of "putrid, malignant, petechial fever," and which was unquestionably typhus. Sir Richard Manningham also described typhoid fever under the title of "febricula, or little fever." In the preface of his work he calls attention to its insidious origin, and to the fact that its gravity was often underrated at its commencement, "till, at length, more conspicuous and very terrible symptoms arise, and then the Physician is sent for in the greatest hurry, and happy for the Patient if the Symptoms, which are most obvious, do not, at this Time, mislead the Physician to the Neglect of the little latent Fever, the true Cause of these violent Symptoms." About the same time Morgagni described certain post-mortem examinations in which the lesions of the intestines were evidently those of typhoid fever. Other authors, whose works bear evidence that they were familiar with the symptoms or lesions of typhoid fever, are Riedel, Roederer and Wagler, Stoll, Rutty, Sarcone, Pepe, Fasano, Mayer, Wrenholt, Sutton, Bateman, Muir, Edmonstone, Prost, Petit and Serres, Cruveilhier, Lerminier, and Andral.

To Bretonneau of Tours appears to belong the credit of having first distinctly pointed out the association between certain symptoms and the lesions of the solitary and agminated glands of the ileum. He regarded the disease of the intestinal glands as inflammatory, and therefore gave to it the name "dothienenterie" or "dothienenterite" (from [Greek: dothiên], a tumor, and [Greek: enteron], intestine), but, unlike Prost, fully recognized the fact that there was no necessary relation between the extent of the intestinal lesions and the gravity of the febrile symptoms. Hirsch, however, claims this honor for Pommer, whose little work on Sporadic Typhus he thinks has not received the consideration its merits deserve. Louis, to whom for his careful study of typhoid fever we owe a large debt of gratitude, was also fully aware of the lesions of the intestinal glands which occur in this disease.

The progress in pathology which observers were making was temporarily impeded about this time by the fact that while typhoid fever was of frequent occurrence in Paris, typhus fever was comparatively rarely met with and had not been epidemic there for several years. Bretonneau, Louis, Chomel, and indeed the greater number of contemporary French physicians, therefore fell into the error of supposing that the fever which was then common in England was identical with that which they were describing, while the English physicians of the period, with but few {240} exceptions, contended with equal strenuousness that there was but one form of continued fever, and that this was very seldom associated with disease of the intestines. In the second edition of his work Louis abandoned his former opinion, and admitted that the typhus fever of the English was a very different disease from that which formed the subject of his treatise; but the confusion which existed in England in regard to this disease was not completely dispelled until the appearance in 1849 and the following two years of several papers on this subject by Sir William Jenner, in which it was conclusively demonstrated that typhoid and typhus fevers were separate and distinct diseases. In Germany, however, the non-identity of these diseases was recognized as early as 1810. Murchison says that the names by which they are still generally known in that country, typhus exanthematicus and typhus abdominalis, were given to them not long after.

The contributions made by American physicians to the knowledge of typhoid fever have been both numerous and important. In 1824 it was described by Nathan Smith under the name of typhus fever of New England, and in 1833, E. Hale, Jr., of Boston, published in the Medical Magazine for December an account of three dissections of persons considered by him to have died of the disease. In reference to these cases, Bartlett says that if the diagnosis could be looked upon as certain and positive they would constitute the first published examples of intestinal lesion in New England. In February, 1835, William S. Gerhard of Philadelphia, who was then under the impression that the two diseases were identical, reported two cases under the name of typhus fever, the symptoms and post-mortem appearances of which he showed differed in no respect from those he had been accustomed to see in the cases of typhoid fever he had observed with Louis during his studies in Paris. The year after Gerhard had, however, the opportunity of observing an epidemic of true typhus fever, and was at once struck with the difference between the symptoms of the cases which then fell under his care and of those he had seen in Paris. In an admirable paper which appeared in the numbers of the American Journal of the Medical Sciences for February and August, 1837, he points out very clearly the differential diagnosis between the two diseases. He particularly insisted on the marked difference between the petechial eruption of typhus and the rose-colored eruption of typhoid fever. He showed that the latter disease was invariably associated with enlargement and ulceration of Peyer's patches and with enlargement of the mesenteric glands, and that these conditions were never presented in the former. He also fully recognized the fact that typhus fever was eminently contagious, while, on the other hand, he was fully aware that typhoid fever was not contagious under ordinary circumstances, "although in some epidemics," he says, "we have strong reason to believe it becomes so." The appearance of this paper marks an epoch in the history of typhoid fever. Murchison, when speaking of it, says that to Gerhard, and Pennock (who was associated with Gerhard in his observations) certainly {241} belongs the credit of first clearly establishing the most important points of distinction between this disease and typhus fever, and M. Valleix alludes to it in terms equally complimentary. It is undoubtedly owing to it, more than to any other cause, that the differential diagnosis of these two diseases was perfectly understood by the great body of the profession in this country long before the question of the relation which they bore to each other was definitely settled in Great Britain, or even in France.

Bartlett gave in the Medical Magazine, June, 1835, a short account of the entero-mesenteric alterations in five cases of unequivocal typhoid fever, which alterations, he said, corresponded exactly to those described by Louis. In the same year, James Jackson, Jr., of Boston, published an account of the intestinal lesions observed by him in cases during the years 1830, 1833, and 1834; and again in a Report of Typhoid Fever, communicated to the Massachusetts Medical Society in June, 1838, says that the alterations of Peyer's patches had been noticed at the Massachusetts General Hospital previous to 1833 in cases which were carefully examined. In 1840, Shattuck of Boston published in the American Medical Examiner an account of some cases of typhoid and typhus fever which he had observed at the London Fever Hospital during the previous year. In this paper, which had been already communicated to the Medical Society of Observation of Paris, and which had unquestionably exerted a marked influence upon medical thought there, he pointed out very fully the distinguishing characteristics of each disease. In 1842, Dr. Bartlett issued the first edition of his work on The History, Diagnosis, and Treatment of the Fevers of the United States, which contains very full descriptions of both of these diseases, and of the means by which they may be distinguished from each other. Since then there have been numerous additions in this country to the literature of typhoid fever, among the most important of which may be mentioned the chapter on the disease in the respective works on The Practice of Medicine by Professors Wood and Flint, the article on typho-malarial fever in the Transactions of the International Medical Congress of 1876, and the article in the work on The Continued Fevers, by James C. Wilson. Abroad, the medical press has been no less active. Within the last twenty or thirty years Jaccoud and Trousseau in France, Liebermeister and Hirsch in Germany, and Tweedie and Cayley in England, have all made important additions to our knowledge of the disease. To the late Dr. Murchison of London, however, is justly due the honor of having produced the best treatise on typhoid fever in any language, and the writer cheerfully acknowledges that he has drawn largely upon it for the material of the present article.

GEOGRAPHICAL DISTRIBUTION.--Although it will be generally admitted that the conditions of civilization favor the occurrence and extension of typhoid fever, yet there is abundant evidence that they are not absolutely necessary to its production, as there is no country, whether civilized or not, of the diseases of which we have any knowledge, in which it has not occasionally made its appearance, being met with in every variety of climate. It is endemic in North America, attacking alike the inhabitants {242} of Greenland and British America and those of Mexico. In our own country it prevails from time to time in every State of the Union, committing its ravages as well among the rocks and hills of New England as in the more fertile valleys of the West and South. In many of the newly-settled portions of our country malarial fevers are, as is well known, exceedingly rife. In proportion, however, as towns and cities spring up, and as the land is properly drained, they diminish in frequency, and are gradually replaced, to a certain extent at least, by typhoid fever; but the influences which produced them retain for a long time enough of power to stamp their impress upon all other diseases. In large portions of the Western and Southern States typhoid fever is therefore rarely uncomplicated, and is much more likely to assume the form which will be fully described later as typho-malarial fever.

Typhoid fever has also occurred frequently in Central America and the West India Islands. It has prevailed from time to time in the states of South America, and occasionally assumed in some of them--as, for instance, Brazil and Chili--an epidemic form.

Typhoid fever is endemic in the British Isles, but, according to Murchison, is most common in England, more common in Ireland than in Scotland, and in Scotland more common on the west than on the east coast. It also exists as an endemic disease in every country of the continent of Europe, from Sweden and Norway on the north to Turkey on the south, and in some of them--as, for instance, France and Germany--would seem to be of much more frequent occurrence than in this country, or even in England. Medical literature is also not deficient in evidence that it has prevailed at various times in all the different countries of Asia and Africa and in Australia. Morehead asserted in the first edition of his Clinical Researches on Diseases in India that India enjoyed an absolute immunity from typhoid fever, but in the second edition of this work he acknowledged that a larger experience had led him to change his opinion on this point. Moreover, the writings of Annesley, Twining, and other Indian authors furnish convincing proof that the disease is by no means unknown in that country. Indeed, even the relative immunity from it which it has been claimed that tropical and subtropical countries possess has been found, upon a fuller study of the diseases of these countries, not to exist to anything like the degree that was formerly supposed.

The occasional occurrence of typhoid fever in islands separated from the main land by a considerable distance--as, for instance, the island of Norfolk, which is situated in the Pacific Ocean four hundred miles west of South America--is an interesting fact, and one which, with the present limits to our knowledge on the subject, it is impossible to explain satisfactorily.

The ETIOLOGY of typhoid fever may be considered under the heads of--1, predisposing, 2, exciting causes.

1. PREDISPOSING CAUSES.--All observers agree that the predisposition to typhoid fever is greater in childhood and early adult life than after thirty years of age. Thus, Murchison states that during twenty-three years nearly one-half the admissions to the London Fever Hospital were of patients between fifteen and twenty-five years of age, and that in more than a fourth, the patients were under fifteen years. On the other hand, {243} in less than a seventh were they over thirty, and in only one in seventy-one did their ages exceed fifty. Taking these facts in connection with the circumstance that the entire population of England and Wales in 1861 was 12,481,323 persons under thirty years of age and 7,584,901 above thirty, it follows, he says, that persons under thirty are more than four times as liable to enteric fever as persons over thirty. Jackson found that the average age of the patients in two hundred and ninety-one cases observed at the Massachusetts General Hospital was a little over twenty-two years, the average age in the fatal cases being somewhat greater than in those in which recovery took place. Liebermeister, from an analysis of a large number of cases treated at the hospital in Basle, has arrived at the same conclusion. No age, however, enjoys a complete immunity from the disease. Manzini has recorded a case in which lesions of Peyer's patches similar to those of typhoid fever were found in a seventh-month foetus which died within half an hour after its birth. Cases are also on record in which death has occurred from this disease in the first few weeks of life. I have myself observed several cases in young children at the Children's Hospital in Philadelphia. The probability is, that it is of even more frequent occurrence in children than is generally supposed, as this class of patients is not often admitted into general hospitals, and as from the absence of some of its characteristic symptoms when it occurs in the very young the nature of the disease is often unrecognized.

On the other hand, the disease occurs not infrequently in advanced life: 83 cases out of 5911 were observed at the London Fever Hospital in persons over fifty, 27 in persons over sixty, and in 2 the age was seventy-five. In a case recorded by D'Arcy the age of the patient was eighty-six, and in one reported by Hamernyk it was ninety. Bartlett long ago contended that the disease was not so rare as was generally supposed among people over forty years of age; and there is really no good reason to believe that the susceptibility to the causes of the disease in an unprotected person diminishes with advancing years, the immunity from this disease which elderly people appear to enjoy being probably due to the fact that, as the disease is not uncommon in early life, they are in many instances protected by having already passed through an attack.

The mean age of the male patients treated at the London Fever Hospital was slightly in excess of that of the female, but in the cases analyzed by Jackson the reverse of this was observed.

The statistics of all general hospitals, with very few exceptions, show a greater or less preponderance of males over females among the typhoid fever patients treated in them. According to Murchison, of 5988 cases admitted into the London Fever Hospital during twenty-three years, 3001 were males and 2987 were females. Of 891 cases admitted into the Glasgow Infirmary during twelve years, 527 were males and 364 females. Liebermeister states that 1297 male typhoid patients and 751 female were treated in the hospital at Basle from 1865 to 1870. Occasionally, the difference is even greater than is indicated by these figures. Thus, of 138 cases observed by Louis, all but 32 occurred in males. When, however, we consider that the proportion of men who apply for admission to hospitals when sick is much larger than that of women, we should hesitate before accepting these statistics as proof that the former {244} are more liable to be attacked by typhoid fever than the latter. Indeed, the opinion which Murchison expresses is generally accepted as correct by authors, that neither sex is more likely than the other to contract the disease. Liebermeister asserts that pregnant and puerperal women and those who are nursing infants enjoy a relative immunity. On the other hand, Nathan Smith says that while the sexes are equally liable to it, more women are cut off by it than men, in consequence of its appearance during pregnancy or soon after parturition.

It was long ago pointed out by certain French observers that newcomers are much more liable to be attacked by typhoid fever than persons who have lived for some time in an infected locality. In 129 cases examined with reference to this point by Louis, the patients in 73 had not resided in Paris more than ten months, and in 102 not more than twenty months. Bartlett noticed that during an epidemic in Lowell which he had the opportunity of observing the disease attacked the recent residents in much larger proportion than the old. Liebermeister also calls attention to this peculiarity of the disease. Murchison's experience in reference to this point has been somewhat similar, for he found upon examination of the records of the London Fever Hospital that 21.84 per cent. of the patients admitted there for typhoid fever had been residents of London for less than two years. Almost all of these patients came, he says, from the provinces of England, and were in good health and comfortable circumstances at the date of their arrival in London and for some time after. Moreover, a large proportion of them were first attacked within a few weeks after changing their residence from one part of London to another. He also refers to instances in which successive visitors at the same house at intervals of months, or even years, have been seized shortly after their arrival with typhoid fever or with diarrhoea, from which the ordinary occupants were exempt. These facts indicate with sufficient clearness that habitual exposure to the causes of the disease confers, to a certain extent at least, an immunity from their effects, just as it does in the various forms of disease arising from malaria. It is not unlikely, as has been suggested by Wilson, that one of the causes of the frequency of typhoid fever in the early autumn in our American cities among well-to-do people is to be formed in the circumstance that during an absence of two months or more in the mountains or by the sea they have to some extent lost the immunity acquired by habitual exposure to sewer emanations, and return to the atmosphere of the city unprotected.

There is no evidence that any particular occupation acts as a predisposing cause of typhoid fever. Among the 621 patients treated at the Pennsylvania Hospital during the last ten years, were representatives of every branch of industry, and the same fact has been observed at every general hospital, not only in this country, but abroad. There is also no reason to believe that the station in life of itself exerts much influence in predisposing to the disease. The rich suffer equally with the poor. It would appear, indeed, that since the recent general introduction of ill-ventilated water-closets and stationary washstands into the houses of the {245} better classes the liability of the former to suffer from the disease is greater than that of the latter.

Persons recovering from an illness or in an infirm condition of health do not appear to be more liable than others to be attacked by typhoid fever. Among the many patients who have fallen under my care only a very few were in ill-health at the time of their seizure. The same fact has been noticed by Murchison and other observers. Indeed, Liebermeister goes so far as to say that typhoid fever attacks by preference strong and healthy persons, while it avoids those suffering with chronic ailments. That this latter class of patients enjoys no immunity from the disease when exposed to its causes is shown by a fact which he himself records. During his service at the hospital at Basle from 1865 to 1871 several of the patients in the medical and surgical wards were attacked by typhoid fever, the cases being especially numerous in two rooms which were situated one directly over the other. Upon investigation it was found that a wooden pipe which extended from the sewer to the roof ran by both of these rooms. The sewer at the point where this pipe ran into it was of faulty construction, and was turned at a right angle, so that the refuse matter collected there. Since this source of infection was made known repeated cleansings, washings, and disinfections have been followed by satisfactory improvement, and Liebermeister believes that if the sewer were entirely altered the infection would disappear.

It would seem only natural that intemperance, by diminishing the powers of resistance in the individual, would increase his liability to contract typhoid fever, but there is no proof that it does so. Few of the patients who have come under my care were intemperate, and still fewer were broken down by this cause. There is also no evidence that grief, fear, or any other depressing emotion is a predisposing cause of the disease, and the same may be said of bodily fatigue and overcrowding. On the other hand, much importance has been attached by writers to idiosyncrasy as a predisposing cause of typhoid fever. What the peculiarities of constitution are which increase the liability to the disease are not definitely known, but there can be no question that it occurs much more frequently, and is much more fatal, in some families than in others.

Typhoid fever occurs with the greatest frequency in this country, as it does with very few exceptions elsewhere, during the latter half of summer and the early part of autumn. Indeed, its greater prevalence at this season than at other times has given to it the name of "autumnal" and "fall fever," by which it is popularly known in many sections of this country as well as of England. On the other hand, the disease is usually at its minimum in May and June. The number of cases, however, does not usually immediately diminish upon the onset of cold weather. On the contrary, R. D. Cleemann, from a comparison of the mortality returns of Philadelphia for a period of ten years, observed that after diminishing in November they not infrequently underwent a marked increase in December. Of 621 cases treated at the Pennsylvania Hospital during the last ten years, 89 were admitted during spring, 259 during summer, 182 during autumn, and 91 during winter. Of 5988 cases treated at the London Fever Hospital, 759 were admitted in the {246} spring, 1490 in summer, 2461 in autumn, and 1278 in winter. Of the whole number, 27.7 per cent. were admitted in the two months of October and November, and in April and May only 7.3 per cent. Hirsch has published statistics which do not differ materially from these. He also mentions the interesting fact that in Rio Janeiro the maximum of the disease occurs in the months from March to June, or, in other words, in the season which in that latitude corresponds to our autumn. There are, however, some exceptions to the general rule of the greater prevalence of the disease during the autumn. Bartlett, who was aware of its greater frequency at that time, refers to an extensive and fatal epidemic which occurred in the city of Lowell in Massachusetts during the winter and early spring; and similar visitations have been observed in other places.

Most authors agree with the statement made by Murchison, that typhoid fever is unusually prevalent after summers remarkable for their dryness and high temperature, and that it is unusually rare in summers and autumns which are wet and cold. Certainly, the severest epidemic of the disease which has been observed in Philadelphia in several years occurred in the year 1876, during and after a summer of exceptionally high temperature, and one characterized by a decidedly diminished rainfall. Still, there can be no question that the increased prevalence of the disease at this time was due, in part at least, to the crowded condition of the city consequent upon the Centennial Exhibition. In 1872, although the mean of the summer temperature was slightly higher than that of 1876, the disease did not prevail in an epidemic form. This may be explained by the fact that the rainfall of the summer months of this year was decidedly greater than the average. Hirsch, however, attaches much less importance to temperature as a factor in the production of typhoid fever than most other authors. He says that he has found, from a comparison of a large number of epidemics, that the disease occurs almost as often in cool as in hot summers, in cold as in warm autumns, and in mild as in severe winters. Murchison, moreover, admits that mere dryness of the atmosphere is not conducive to an increase of typhoid fever. On the contrary, he says, warm, damp weather, when drains are most offensive, is often followed by an outbreak of the disease.

The relation which temperature and moisture bear to the causation of typhoid fever is therefore not definitely ascertained. It is certain, however, that the largest number of cases does not occur at the period of the greatest heat, but is usually not observed until from six weeks to two months afterward, and the minimum is not reached until about the same length of time after that of the most intense cold. This difference in time Murchison explains by the hypothesis that the cause of the disease is exaggerated or only called into action by the protracted heat of summer and autumn, and that it requires the protracted cold of winter and spring to impair its activity or to destroy it. On the other hand, Liebermeister, who believes that the breeding-places of typhoid fever lie deep in the earth, holds that the time is consumed in the penetration of the changes of temperature to the place where the typhoid poison is elaborated, in the development of the poison without the human body, and in the period of incubation. In some places the maximum of the disease is observed earlier in the year than in others. In Berlin, for {247} instance, the largest number of fatal cases occurs in October, while in Munich it does not occur until February. This depends, he thinks, upon the difference in the distance beneath the earth's surface of these breeding-places in different localities, and the deeper they are the longer, he says, will it be before they are affected by the heat of summer or the cold of winter, since the changes of the temperature of the air are followed by corresponding changes in the temperature of the earth more and more slowly the deeper we go beneath the surface.

Buhl and Pettenkofer have, as the result of a series of observations carried on in Munich over a number of years, reached the conclusion that an intimate relation exists between the variations in the degree of prevalence of typhoid fever and the rise and fall of water in the soil. When the springs were low they found that there was a marked increase in the number of cases; when, on the other hand, they were high, there was just as decided a diminution. Out of this fact they have evolved the theory that the cause of typhoid fever lies deep in the soil, and has the power of multiplying itself there, and that this property is very much increased when the water-level sinks, and the upper layers of the earth are consequently exposed to the air. It is, on the contrary, diminished when the water-level rises and the earth is again saturated with moisture. It is unquestionably true, as has already been stated, that it is principally after hot and dry weather, when the springs are of course low, that typhoid fever is most prevalent, and that it very frequently subsides after the occurrence of very heavy rains; but it is not necessary to adopt the theory of Buhl and Pettenkofer to explain these facts. It seems quite as probable that the increased prevalence of the disease after dry weather is due, as suggested by Buchanan and Liebermeister, to the greater amount of solid matter which is then suspended in the water of the springs. A larger proportion of the germs of the disease, if there should be any present in the soil, will therefore be contained in any given quantity of the drinking-water. The theory fails to account, as pointed out by Murchison, for the connection which is frequently observed between defective house-drainage and outbreaks of typhoid fever, occurring irrespectively of any variations in the subsoil water. And, moreover, outbreaks of the disease have occurred under precisely opposite circumstances, as the outbreak at Terling in 1867, recorded by Thorne, which was coincident with a rise in the subsoil water after drought.

It is believed in many parts of our country that there is an antagonism between typhoid fever and the various forms of malarial fever, and it is unquestionably true that in many districts in which the latter were formerly prevalent they have ceased to be frequent, and have been replaced apparently by the former. In the cultivation of the soil the causes of malarial fever disappear, or at least become less potent. On the other hand, the increase of population and the neglect of all sanitary laws in the building of towns, and the construction of sewers with their house connections, seem to favor the occurrence of typhoid fever. But there is no real antagonism between the diseases. During the recent Civil War typhoid fever was not infrequently developed in soldiers suffering from malarial disease. Indeed, so frequent was it to have the manifestations of the two diseases in the same individual that many observers at that {248} time supposed they had a new disease to deal with, to which they gave the name of typho-malarial fever.

2. EXCITING CAUSES.--Much diversity of opinion has existed in times past and to a certain extent continues to exist, in regard to the contagiousness of typhoid fever. In the early part of this century there was quite a number of good observers, including Nathan Smith in this country, and Bretonneau and Gendron of Château du Loir in France, who held the opinion it was an eminently contagious disease. Indeed, Smith went so far as to say that its contagiousness was as fully demonstrated as that of measles, small-pox, or any other disease universally admitted to be contagious. This was also the opinion of William Budd, who maintained that the contagious nature of typhoid fever was the master truth in its history. The late Sir Thomas Watson was also a warm supporter of the same view. At the present time, however, the large majority of physicians, whose opportunities for observation give weight to their opinions, do not regard the disease as contagious in the strict sense of the word. During the past twenty-four years I have been almost uninterruptedly connected with large general hospitals, and during that time have had a large number of cases of typhoid fever under my care, and a still larger number more or less under my observation. During all this time I have never known but one case to originate within a hospital, and that occurred in a servant whose duties did not bring her in immediate contact with the sick. Murchison's experience with a much larger number of cases has been very similar. In twenty-three years, in which 5988 cases were treated in the London Fever Hospital, only 17 residents contracted the disease, and most of these had no personal contact with the sick. Liebermeister asserts that he has never known a case to originate in a hospital from direct contagion. When such cases appeared to have occurred, they could generally be traced, he says, to some defective sanitary condition of the hospital.

There are, nevertheless, many facts on record which, unless duly weighed, appear to lend a good deal of support to the theory of the contagiousness of typhoid fever. Among the most important of these are (1) the occurrence in rapid succession of several cases in the same house, and (2) the limited epidemics which occasionally follow the arrival of an infected person into a previously healthy locality. These facts are, however, susceptible of an entirely different explanation.

1. In those instances in which several cases of the disease have occurred in the same house, it not infrequently happens that some defect in its sanitary conditions is detected, or that the drinking-water is found to be impure. The same cause which produced the first case may, therefore, also have produced those which succeeded it. Indeed, the interval between the cases is sometimes so short that for this reason alone, if there were no other, they could scarcely be attributed to contagion. It not infrequently happens that the seizure of one member of a large family is followed on the next day by that of another, and on the third or fourth by that of still another. Now, while it is undoubtedly true that the period of incubation has appeared in some cases to be very short, we know that under ordinary circumstances it is usually about two weeks.

2. The explanation of the second fact is not more difficult, but in order that it may be clear to the reader it will be well to give in detail a few {249} of the instances on record in which the arrival of an individual sick with typhoid fever in a previously healthy locality has been followed by an outbreak of the disease. Nathan Smith refers to two cases of this character. In both of these the disease appeared to be communicated to several individuals by patients who had contracted the disease elsewhere. So little is said in the reports of these cases of the water-supply of the localities in which they occurred, or of the manner of disposing of the discharges of the patients, that they would scarcely now be used as arguments in favor of the contagiousness of the disease. The report of a local epidemic by Austin Flint, Sr., is more satisfactory in this respect, and is as follows: A stranger was detained in a small village near Buffalo by an illness which proved fatal in the course of a few days, and which was recognized as typhoid fever by his attending physicians. Up to this time, it is stated, typhoid fever had never been known in the neighborhood. In the course of a month more than one-half of the population, numbering forty-three, was attacked by the disease, and ten had died. The family of the tavern-keeper at whose house the stranger lodged was the first to suffer, and of the families immediately surrounding the tavern but one wholly escaped, that of a man named Stearns. Upon investigation, it was ascertained that this family alone, of all these families, did not use the well belonging to the tavern, but had its own water-supply. The occurrence of the disease naturally produced great excitement, and Stearns, between whom and the tavern-keeper a quarrel existed, was suspected of having poisoned the well; but an examination of the water showed this suspicion to be unfounded. There can, however, be little doubt that the water of the well, which was in all probability contaminated by the discharges of the stranger, was the means of propagating the disease; for although it is said that the family of Stearns was cut off by the quarrel from all intercourse with that of the tavern-keeper--a fact upon which some stress is laid by Flint--it does not appear that a similar isolation existed as regards the other families affected.