ventilation of the city),' and the disappearance, after sanitary improvements, of the Pali plague in India, and its recurrence on the cessation of preventive measures, show that, like typhus, the bubo plague is easily preventible. Elevation, as in so many other specific diseases, has a considerable effect; the village of Alum Dagh, near Constantinople (1,640 feet above the sea), and freely ventilated, has never been attacked; the elevated citadel of Cairo has generally been spared; and when Barcelona was attacked, the elevated citadel also escaped.

Typhoid or Enteric Fever.

External Cause.-A poison of animal origin; one mode of propagation is by the intestinal discharges of persons sick of the disease; other modes of origin and transmission are not disproved. There is doubtless a frequent transmission of the disease by the diarrhoea of mild cases which are often not diagnosed. There is some evidence that persons considered convalescent may carry the disease,' but it is possible that this may have been owing to badly washed clothes. The mode of entrance into the body is both by air and water. Entrance by food (milk) has been lately also proved. As means of arresting the disease, isolate the patients; receive all evacuations (fæces and urine) into the vessels strictly kept for one sick person; place zinc chloride, or ferrous sulphate, or carbolic acid, etc., in the vessels; never empty any evacuation into a closet, sewer, or cesspool; bury it several feet deep, and mix it well with earth. Fumigate, and heat to 220° Fahr., all clothes and bedding. As means of prevention, attend especially to the purity of the drinking water, and to the disposal of sewage; although the origin of typhoid merely from putrefying non-typhoid sewage is not considered at present to be probable, it is not disproved, and it is certain that the disease may spread by the agency of sewers and fecal decomposition. A single case of typhoid fever should at once be held to prove that something is wrong with the mode of getting rid of the excretions. If neither water nor sewers can be proved to be in fault, consider the milk and other food supply.

Internal Causes.-As a first attack preserves in a great measure from a second, a peculiar condition of body is as essential as in small-pox; and looking to the special effect produced on Peyer's patches, and to the fact that at the period of life when these patches naturally degenerate, the susceptibility to typhoid fever materially lessens, or even ceases, it seems possible that the internal cause or necessary second condition is the existence of these patches, the structures in which are brought into an abnormal state of activity by the direct or indirect action of the poison on them. The other internal causes are anything which causes gastro-intestinal disorder, such as bad water, and general feebleness.

Relapsing Fever.

No preventive measures have been yet pointed out, but the occurrence of the disease in times of famine seems to indicate that feebleness and inanition are necessary internal causes.

The measures adopted in Cairo blowing over the city, filling The peculiar sepulture cussole cause of the origin of

'Stamm, in Pappenheim's Beiträge, 1862-63, p. 80. were levelling some hillocks, which stopped the air from up some marshes, and adopting a better mode of burial. toms of the Copts have indeed even been assigned as the plague.

Gietl., Die Ursachen der enterischen Typhus in München, 1865, pp. 74 and 94.

Bilious Remittent Fevers.

Under this vague term, a disease or diseases, which in many points are like relapsing fever, but yet are not identical (Marston), have been described as occurring especially in Egypt (Griesinger), and in the Levant generally. It has also been described by Drs. Marston and Boileau,' at Malta. The exact causes are not known; but in some of the writings of the older army surgeons, the fevers which are produced by foul camps (in addition to typhoid) appear to have a close resemblance to the bilious remittent fevers of the Mediterranean. They appear to be connected with bad sanitary conditions, but their exact causation is not clear.

Cerebro-Spinal Meningitis.

This disease, which has occasionally been noticed in France, and especially among soldiers, for the last half century, has within late years appeared in several parts of Germany, and a few cases among civilians have occurred in England. It seems to depend on a specific agent, but very little is yet known about it. It does not appear to be contagious. No preventive measures can be at present suggested.

The Eruptive Fevers.

Small-pox is guarded against in the army by repeating vaccination in the case of recruits, and by occasional re-vaccination of all the men in a regiment. In the statistical reports, great attention is always paid to this important point, and the evidence from foreign armies proves the necessity of careful re-vaccination.

If the disease does occur, isolation' (in separate buildings) is most important, but the aggregating of a large number of cases together ought to be avoided.

In the case of scarlet fever and measles, nothing definite is known with regard to prevention, except that a good sanitary condition seems to lessen their intensity, and probably their spread. The evidence with regard to belladonna in scarlet fever is contradictory, but on the whole unfavorable. All the discharges should be disinfected, and the skin well rubbed over with camphorated oil and a little weak carbolic acid.

The most difficult case is when either measles or scarlet fever appears on board ship, and especially if children are on board. If the weather permit, the best plan is then to treat all patients on the upper deck under an awning. If this cannot be done (and scarlet fever patients must not be exposed to cold), they must be isolated as much as possible. Both in scarlet fever and small-pox there is some evidence to show that the incubative period may be very long.'

Perhaps, in the present state of evidence, it might be desirable to try the prophylactic effects of belladonna on board ship, directly the first case

occurs.

1 Army Med. Reports, vols. iii. and viii.

* Buchanan gives a good example of the advantages of isolation in the case of Cheltenham, where small pox was introduced into the town six times, but, in consequence of proper hospital accommodation for all classes, never made good its footing.

3 See a case by Bryson (Trans. Soc Science Assoc., 1862, p. 677), for a case in which the incubative period of small-pox appeared to be thirty-one days. In scarlet fever it is said to be sometimes even longer.

Erysipelas (Hospital or Epidemic).

External Cause.-It is well known that in the surgical wards of hospitals erysipelas occasionally occurs, and then may be transmitted from patient to patient. The exact causes of its appearance have not been made out, but it is evidently connected with overcrowding and impure air. Moisture of the floors, causing constant great humidity of air, has also been supposed to aid it. It is much more common in fixed hospitals than in tents and huts, and indeed is exceedingly rare in the two latter cases. The agencies or agent can scarcely be supposed to be other than putrefying organic matter and pus-cells passing into and accumulating in the air, or organisms developed in connection with them. It is remarkable that pus-cells derived from purulent sputa do not cause erysipelas in medical wards, but this may be from a want of open wounds to give the necessary personal condition.

When hospital erysipelas has once appeared in a ward, nothing will avail except complete clearance of the ward, scraping the floors, and often the walls, washing with chloride of lime, and then with solution of caustic lime, and thorough fumigation with chlorine and nitrous acid alternately. The erysipelatous cases should be placed in well-ventilated tents.

Considering the undoubted beneficial influence of tent life, it may be a question whether, even in civil life, hospitals which possess gardens should not, during the summer, treat their surgical cases with suppurating wounds in the tents. In many continental towns the large hospitals have now wooden huts attached to them, in which the surgical cases are treated.

Of course, extreme care in conservancy of wards or tents, the immediate removal of all dressings, great care in dressing wounds, so that neither by instruments, sponges, lint, or other appliances, pus-cells or molecular organic matter shall be inoculated, are matters of familiar hospital hygiene. The use of carbolic acid and other antiseptics, as introduced by Professor Lister, will, it is hoped, greatly lessen the chances of spread in the case of erysipelas as well as of hospital gangrene."

Internal Causes.-Nothing is known on this point, except that there must be some abrasion or wound of the surface or of the passages near the surface, as the vagina or throat. The erysipelas commences at the point of abrasion. If there is no open wound, the atmospheric impurity seems to have no bad effect on the persons who are exposed to it, but it would be interesting to know if some forms of internal disease are not produced. Is it possible that some forms of tonsillitis and diphtheritic-like inflammation of the throat may be caused in this way, although there is no solution of continuity?

Hospital Gangrene.

Almost the same remarks apply to hospital gangrene as to erysipelas. One of the most important facts, which has been pointed out by many writers, and which has been thoroughly proved by the American and the Italian wars, is that perfectly free ventilation prevents hospital gangrene. Hammond, the late Surgeon-General of the United States Army, declares'

See Hammond's Hygiene, 1863; Kraus' Das Kranken und Zerstreuungs-System, 1861; and a Report on Hygiene, by Dr. Parkes, in the Army Medical Report for 1862, for the effects of tents on erysipelas and hospital gangrene.

* I was informed, in Munich, that Lister's system has completely banished hospital gangrene from that city, and I believe the same result has been noticed in other German towns.(F. de C.) 3 Hygiene, p. 397.

that only one instance has come to his knowledge in which hospital gangrene has originated in a wooden,pavilion hospital, and not one which has occurred in a tent. Kraus also, from the experience of the Austrians in 1859, states that it never could be discovered that gangrene originated in a tent. On the contrary cases of gangrene at once commence to improve when sent from hospital wards into tents. On the other hand, the tenacity with which the organic matters causing the gangrene adhere to walls is well known.

The measures to be adopted in wards when hospital gangrene occurs, and the ward cannot be at once evacuated, are the same as for erysipelas.1 It is not necessary to do more than allude to the undoubted transference by dirty sponges, etc., and to the beneficial effects of antiseptic dressings.

SECTION II.

VARIOUS NON-SPECIFIC DISEASES.

Dysentery and Diarrhea.

At present there is no evidence that the dysentery arising from various causes has different anatomical characters, or runs a different course, except perhaps in the case of malarious dysentery. The chief causes are—

1. Impure Water.-Both Annesley and Twining have directed attention to this cause, in their accounts of Indian dysentery. It is scarcely possible that, with common attention, this cause should not be discovered and removed.

2

2. Impure Air.-The production of dysentery and diarrhoea from the effluvia of putrefying animal substances is an opinion as old as Cullen, and probably older; and there seems little doubt of its correctness. The gases and vapors from sewers also will, in some persons, cause diarrhœa; and also effluvia from the foul bilge-water of ships. On the other hand, very disagreeable effluvia from many animal substances, as in the case of boneburners, fat-boilers, etc., do not seem to cause diarrhoea. In India there appears to be a decided relation between the prevalence of dysentery and overcrowding and want of ventilation in barracks; massing a large number of men together is certainly an accessory cause of great weight."

3

The air from very foul latrines has caused dysentery in numerous cases. Pringle, and many other army surgeons, record cases. In war this is one of the most common causes. The occasional production of dysentery from sewage applied to land, seems to be proved by Clouston's observations on

1 With regard to pyæmia, observations show that one of the external causes is fetid organic emanations. Spencer Wells (Med. Times and Gazette, 1862) states, that in 1859 the mortality from pyæmia was great in some wards over a dissecting-room. On removing all the cases after operation to the opposite side of the building, pyæmia almost disappeared. Other similar cases are on record.

2 Fonssagrives (Traité d'Hygiène Navale, p. 60) records a good case of this kind. It commenced after a gale at sea had stirred up the bilge, and on clearing it out the attack ceased.

3 Wood on the Health of European Soldiers in India, 1864, p. 45 et seq.

Sir James M'Grigor, Vignes (who give many cases from the French experience in the Peninsula), Chomel, Copland; see also the Dic. des Sciences Méd., art." Dysentérie." D'Arcet (Ann. d'Hygiène, vol. xii., p. 390) records a good case, in which a whole regiment was affected in the Hanoverian war, from having used too long the same trench as a latrine. The disease disappeared when another was dug.

the cause of the attack of dysentery in the Cumberland Asylum.' Still sewage matter has been often applied in this way without bad effects. In Dr. Clouston's case the sewage was 300 yards from the ward where the dysentery occurred. Calm and nearly stagnant nights, or with a gentle movement of air from the sewage toward the ward, were the conditions which preceded most of the attacks.

Of all the organic effluvia, those from the dysenteric stools appear to be the worst. Some evidence has been given to show that dysentery arising from a simple cause (as from exposure to cold and wet), when it takes on the gangrenous form, and the evacuations are very fetid, produces dysentery in those who use the latrines, or unclean closets, into which such gangrenous evacuations are passed. If correct, this is a most interesting point, as it seems to show the origin of a communicable poison de novo. Possibly, in all these cases, effluvia, or organic matters, or particles disengaged from the putrefying evacuations, act at once on the anus, and the disease then spreads up by continuity.

There is some reason, also, to think that retaining dysenteric stools in hospital wards spreads the disease; and, perhaps, in this case, the organic particles floating up may be swallowed, and then act on the mucous membrane of the colon. In the epidemic of dysentery in Sweden in 1859, there was good evidence to show that it spread by means of the diarrhoeal and dysenteric evacuations. In all cases the stools must be mixed with disinfectants, and immediately removed from the wards and buried.

2

3. Improper Food.-Any excess in quantity, and many alterations in quality (especially commencing decomposition in the albuminates, and, perhaps, the rancidity of the fatty substances) cause diarrhoea, which will pass into dysentery. But the most important point in this direction is the production of scorbutic dysentery. A scorbutic taint plays a far more important part in the production of dysentery than is usually imagined, and there is now no doubt that the fatal dysentery, which formerly was so prevalent in the West Indies, was of this kind. Much of the Indian dysentery is also often scorbutic.

4. Exposure to Cold and Wet.-Exposure to cold, especially after exertion, and extreme variations of temperature, have been assigned as the chief cause of dysentery by numerous writers; great moisture has been assigned by some writers (Twining, Annesley, Griesinger) as a cause; and great dryness of the air by others (Mouat); while a third class of observers have considered the amount of moisture as quite immaterial.

Hirsch, after summing up the evidence with respect to the temperature with great care, decides that sudden cold after great heat is merely a "causa occasionalis which may aid the action of the more potent cause

1 Medical Times and Gazette, June, 1865.

* British and Foreign Med. Chir. Rev., January, 1866, p. 140.

A few only can be noted; Stall, Zimmermann, Huxham, Durandeau, Willan, Irvine, James Johnson, Annesley, Bampfield, Morehead, Vignes, Fergusson, etc. Fergusson says: "True dysentery is the offspring of heat and moisture; of moist cold in any shape after excessive heat. Nothing that a man can put into him would ever give him true dysentery."

Handbuch der Historisch-Geograph. Pathol., Band ii., p. 234.

The so-called "hill diarrhoea," which was formerly prevalent on some of the hill sanitaria in India, especially on the spurs of the Himalayas, has been attributed to the effect of cold and moisture, and sudden changes of temperature. But, as remarked by Dr. Alexander Grant, many hill stations have these atmospheric conditions without having any hill diarrhoea. There is great reason to suppose the hill diarrhoea to be entirely unconnected with either elevation or climate. In some cases it has been VOL. II.-10