The causes concerned in its production include both the predisposing and the exciting. Of the former the most powerful of all are those influences which lower the health of a community, especially overcrowding and poverty. Hence this fever is most frequently found to affect the poor of large cities and towns, or to appear where large numbers of persons are living crowded together in unfavourable hygienic conditions, as has often been seen in prisons, workhouses, &c. Armies in the field are also liable to suffer from this disease; for instance, during the Crimean War it caused an enormous mortality among the French troops. Some high authorities, including Dr Murchison, have held that such conditions as those referred to are capable of generating typhus fever by themselves, and the apparent occasional de novo origin of this disease has doubtless the support of many striking facts which would appear to favour this view (see Pathology, vol. xviii. p. 803). In the light, however, of recent researches into the relation of specific disease germs to the production of fevers and other infectious maladies, there is increasing difficulty in maintaining this position; and the direction of opinion is decidedly towards the view that, however much insanitary conditions and overcrowding act as causes predisposing to the reception of the disease, the introduction into the system of a living organism or germ is necessary to the manifestation of the phenomena of the fever. Nevertheless no specific organism has yet been clearly identified in the case of typhus fever. This disease is now much less frequently encountered in medical practice than formerly, —a fact which must mainly be ascribed to the great attention which in recent times has been directed to improvement in the sanitation of towns, especially to the opening up of crowded localities so as to allow the free circulation through them of fresh air. In most large cities, however, limited epidemic outbursts of the disease occur from time to time, under the conditions of overcrowding and poverty, although the increased facilities possessed by local authorities for recognizing such outbreaks, and for the prompt isolation or removal of infected persons to hospitals, operate in general effectually to prevent any extensive spread of the fever. All ages are liable to typhus, but the young suffer less severely than the old. The disease appears to be communicated by the exhalations given off from the bodies of those suffering from the fever, and those most closely in contact with the sick are most apt to suffer. This is shown by the frequency with which nurses and physicians take typhus from cases under their care. As in all infectious maladies, there is often observed in typhus a marked proclivity to suffer in the case of individuals, and in such instances very slight exposure to the contagion may convey the disease. Typhus is highly contagious throughout its whole course and even in the early period of convalescence. The contagion, however, is rendered less active by the access of fresh air; hence this fever rarely spreads in well-aired rooms or houses where cases of the disease are under treatment. As a rule one attack of typhus confers immunity from risk of others, but numerous exceptions have been recorded.

The course of typhus fever is characterized by certain well-marked stages. (1) The stage of incubation, or the period elapsing between the reception of the fever poison into the system and the manifestation of the special evidence of the disease, is believed to vary from a week to ten days. During this time, beyond feelings of languor, no particular symptoms are exhibited. (2) The invasion of the fever is in general well marked and severe, in the form of a distinct rigor, or of feelings of chilliness lasting for hours, and a sense of illness and prostration, together with headache of a distressing character and sleeplessness. Feverish symptoms soon appear and the temperature of the body rises to a considerable height (103°-105° Fahr.), at which it continues with but little daily variation until about the period of the crisis. It is, however, of importance to observe certain points connected with the temperature during the progress of this fever. Thus about the seventh day the acme of the fever heat has been reached, and a slight subsidence (1° or less) of the temperature takes place in favourable cases, and no further subsequent rise beyond this lowered level occurs. When it is otherwise, the case often proves a severe one. Again, when the fever has advanced towards the end of the second week, slight falls of temperature are often observed, prior to the extensive descent which marks the attainment of the crisis. The pulse in typhus fever is rapid (100-120 or more) and at first full, but later on feeble. Its condition as indicating the strength of the heart’s action is watched with anxiety. The tongue, at first coated with a white fur, soon becomes brown and dry, while sordes (dried mucus, &c.) accumulate upon the teeth; the appetite is gone and intense thirst prevails. The bowels are as a rule constipated, and the urine is diminished in amount and high-coloured. The physician on examination may make out distinct enlargement of the spleen. (3) The third stage is characterized by the appearance of the eruption which generally shows itself about the fourth or fifth day or later, and consists of dark red (mulberry coloured) spots or blotches varying in size from mere points to three or four lines in diameter, very slightly elevated above the skin, at first disappearing on pressure, but tending to become both darker in hue and more permanent. They appear chiefly on the abdomen, sides, back, and limbs, and occasionally on the face. Besides this, the characteristic typhus rash, there is usually observed a general faint mottling all over the surface. The typhus rash is rarely absent and is a very important diagnostic of the disease. In the more severe and fatal forms of the fever, the rash has all through a very dark colour, and slight subcutaneous haemorrhages (petechiae) are to be seen in abundance. After the appearance of the eruption the patient’s condition seems to be easier, so far as regards the headache and discomfort which marked the outset of the symptoms; but this is also to be ascribed to the tendency to pass into the typhous stupor which supervenes about this time, and becomes more marked throughout the course of the second week. The patient now lies on his back, with a dull dusky countenance, an apathetic or stupid expression, and contracted pupils. All the febrile symptoms already mentioned are fully developed, and delirium, usually of a low muttering kind, but sometimes wild and maniacal (delirium ferοx) is present both by night and day. The peculiar condition to which the term “coma vigil” is applied, in which the patient, though quite unconscious, lies with eyes widely open, is regarded, especially if persisting for any length of time, as an unfavourable omen. Throughout the second week of the attack the symptoms continue unabated; but there is in addition great prostration of strength, the pulse becoming very feeble, the breathing shallow and rapid, and often accompanied with bronchial sounds. (4) A crisis or favourable change takes place about the end of the second or beginning of the third week (on an average the 14th day), and is marked by a more or less abrupt fall of the temperature (vide chart) and of the pulse, together with slight perspiration, a discharge of loaded urine, the return of moisture to the tongue, and by a change in the patient’s look, which clears up and shows signs of returning intelligence. Although the sense of weakness is extreme, convalescence is in general steady and comparatively rapid.

Typhus fever may, however, prove fatal during any stage of its progress and in the early convalescence, either from sudden failure of the heart’s action—a condition which is specially apt to arise— from the supervention of some nervous symptoms, such as meningitis or of deepening coma, or from some other complication, such as bronchitis. Further, a fatal result sometimes takes place before the crisis from sheer exhaustion, particularly in the case of those whose physical or nervous energies have been lowered by hard work, inadequate nourishment and sleep, or intemperance, in all which conditions typhus fever is apt to assume an unusually serious form.

Occasionally troublesome sequelae remain behind for a greater or less length of time as the effects of the fever. Among these may be mentioned mental weakness or irritability, occasionally some form of paralysis, an inflamed condition of the lymphatic vessels of one leg (the swelled leg of fever), prolonged weakness and ill health, &c. Gradual improvement, however, may be confidently anticipated and even ultimate recovery.

The mortality from typhus fever is estimated by Murchison and others as averaging about 18 per cent. of the cases, but it varies much according to the severity of type (particularly in epidemics), the previous health and habits of the individual, and very specially the age,— the proportion of deaths being in striking relation to the advance of life. Thus, while in children under fifteen the death-rate is only 5 per cent., in persons over fifty it is about 46 per cent.

The treatment of typhus fever includes the prophylactic measures of attention to the sanitation of the more densely populated portions of towns. The opening up of cross streets intersecting those which are close-built and narrow, whereby fresh air is freely admitted, has done much to banish typhus fever from districts where previously it was endemic. Further, the enforcement of the law regulating the number of persons accommodated in common lodging-houses, and the application of the powers now vested in local authorities for dealing with eases of overcrowding everywhere, and for isolation and treatment of the infected, have had a like salutary effect. Where typhus has broken out in a crowded district the prompt removal of the patients to a fever hospital and the thorough disinfection and cleansing of the infected houses are to be recommended. Where, on the other hand, a single case of accidentally caught typhus occurs in a member of a family inhabiting a well-aired house, the chance of it being communicated to others in the dwelling is but small; nevertheless every precaution in the way of isolation and disinfection should be taken.

The treatment of a typhus patient is conducted upon the same general principles as have been illustrated in other fevers (see Scarlet Fever, Smallpox). Complete isolation should be maintained throughout the illness, and the services of a day and a night nurse procured, who should keep a strict watch and preserve a record of the temperature and other observations, the times of feeding and the form of nourishment administered, as well as every other fact noticed, for the physician’s information. Due attention should be given to the ventilation and cleansing of the sick chamber. The main element in the treatment of this fever is good nursing, and especially the regular administration of nutriment, of which the best form is milk, although light plain soup may also be given. The food should be administered at stated intervals, not, as a rule, offener than once in one and a half or two hours, and it will frequently be necessary to rouse the patient from his stupor for this purpose. Sometimes it is impossible to administer food by the mouth, in which case recourse must be had to nutrient enemata. Alcoholic stimulants are not often required, except in the case of elderly and weakly persons who have become greatly exhausted by the attack and are threatening to collapse. The best indication for their use is that furnished by the condition of the circulation: when the pulse shows unsteadiness and undue rapidity, and the first sound of the heart is but indistinctly heard by the stethoscope, the prompt administration of stimulants (of which the best form is pure spirit) will often succeed in averting danger. Should their use appear to increase the restlessness or delirium they should be discontinued and the diffusible (ammoniacal or ethereal) forms tried instead.

Many other symptoms demand special treatment. The headache, which persists for days at the commencement and is with many a very distressing symptom, may be mitigated by removing the hair and applying cold to the head. The sleeplessness, with or without delirium, may be combated by quietness, by a moderately darkened room (although a distinction between day and night should be made as regards the amount of admitted light), and by soothing and gentle dealing on the part of the nurse. Opiate and sedative medicines in any form, although recommended by many high authorities, must be given with great caution, as their use is often attended with danger in this fever, where coma is apt to supervene. When resorted to, probably the safest form is a combination of the bromide of potassium or ammonium with a guarded amount of chloral. The writer has seen alarming effects follow the administration of opium. Occasionally the deep stupor calls for remedies to rouse the patient, and these may be employed in the form of mustard or cantharides to the surface (calves of legs, nape of neck, over region of heart, &c. ), of the cold affusion, or of enemata containing turpentine. The height of the temperature may be a serious symptom, and antipyretic remedies appear to have but a slight influence over it as compared to that which they possess in typhoid fever, acute rheumatism, &c. The cold bath treatment, which has been recommended, cannot be carried out without serious risk to life in the necessary movement of the patient. It is a well-recognized rule that persons suffering from typhus fever ought not to be moved up in bed for any purpose after the first few days. Cold sponging of the hands and feet and exposed parts, or cold to the head, may often considerably lower the temperature. Throughout the whole progress of a case the condition of the bladder requires special attention, owing to the patient’s drowsiness, and the regular use of the catheter becomes, as a rule, necessary with the advance of the symptoms.

The complications and results of this fever fall to be dealt with according to the methods of treatment applicable to their character and extent.

Typhoid or Enteric Fever.

Typhoid or enteric fever (ἔvτερov, the intestine) is a continued fever characterized mainly by its insidious onset, by a peculiar course of the temperature, by marked abdominal symptoms occurring in connexion with a specific lesion of the bowels, by an eruption upon the skin, by its uncertain duration, and by a liability to relapses.

This fever has received various names, such as gastric fever, abdominal typhus, infantile remittent fever, slow fever, nervous fever, &c. Dr Murchison, in reference to its supposed origin in putridity, uses the term “pythogenic fever,” but this designation has not been generally adopted. Up till a comparatively recent period typhoid was not distinguished from typhus fever. For, although it had been noticed that the course of the disease and its morbid anatomy were different from those of ordinary cases of typhus, it was believed that they merely represented a variety of that malady. The distinction between the two diseases appears to have been first accurately made in 1836 by Messrs Gerhard and Pennock of Philadelphia, and still more fully demonstrated by Dr A. P. Stewart of Glasgow (afterwards of London). Subsequently all doubt upon the subject was removed by the careful clinical and pathological observations made by Sir William Jenner at the London fever hospital (1849-51). A clear distinction has been established between the two fevers, not only as regards their phenomena or morbid features, but equally as regards their origin. While typhus fever is a disease of overcrowding and poverty, typhoid may occur where such conditions are entirely excluded; and the connexion of this malady with specific emanations given off from decomposing organic or faeculent matters, or with contamination of food or water by the products of the disease, is now almost universally admitted. Alike in sporadic cases and in extensive epidemic outbreaks the existence of insanitary conditions in house drainage, water supply, &c., can in the majority of instances be made out. The question whether such conditions alone will suffice to beget this fever—or, in other words, its de novo origin—has, as in the case of typhus, been much discussed, and an affirmative opinion expressed by some high authorities. But the same remark must again be made as to the difficulties in the way of maintaining such a position in view of the evidence of the part played by microbes in infective processes.

That all insanitary conditions in respect of drainage of houses and localities furnish the most ready means for the introduction of the contagion of typhoid there is a general agreement, as there is equally that the most certain means of preventing its appearance or spread are those which provide a thoroughly trustworthy and secure drainage, a safe method of disposal of sewage, and a pure and abundant water supply. Typhoid fever is much less directly communicable from the sick to the healthy than typhus. The infective agent appears to reside in the discharges from the bowels, in which, particularly when exposed and undergoing decomposition, the contagium seems to multiply and to acquire increased potency. Thus in sewers, drains, &c., in association with putrefying matter, it may increase indefinitely, and by the emanations given off from such decomposing material accidentally escaping into houses, or by the contamination of drinking water in places where wells or cisterns are exposed to faecal or sewage pollution, the contagion is conveyed. Of the precise nature of the contagious principle we have as yet no full information, but there appears to be strong reason for believing that a specific microbe or organism plays a part in the propagation of the disease. Still it is obvious that for its successful implantation in and effect upon the system a peculiar condition of preparedness or receptivity to the morbific agent must be presupposed to exist in the individual, regarding which also our knowledge is of the vaguest. There is abundant evidence that one of the vehicles for the conveyance of the contagion is food, especially milk, which may readily become contaminated with the products of the disease where an outbreak of the fever has occurred in a dairy.

Typhoid fever is most common among the young, the majority of the cases occurring between the ages of fifteen and twenty-five (Murchison). But children of any age may suffer, as may also, though more rarely, persons at or beyond middle life. It is of as frequent occurrence among the well-to-do as among the poor. The greater number of cases appear to occur in autumn. In all countries this fever seems liable to prevail; and, while some of its features may be modified by climate and locality, its main characters and its results are essentially the same everywhere.

The more important phenomena of typhoid fever will be better understood by a brief reference to the principal pathological changes which take place during the disease. These relate for the most part to the intestines, in which the morbid processes are highly characteristic, both as to their nature and their locality. The changes (to be presently specified) are evidently the result of the action of the contagium on the system, and they begin to show themselves from the very commencement of the fever, passing through various stages during its continuance. The portion of the bowels in which they occur most abundantly is the lower part of the small intestine (ileum), where the “solitary glands” and “Peyer’s patches” on the mucous surface of the canal become affected by diseased...