carrying agency, than that any effluvia should pass off from the lungs and skin which could spread to a great distance.

Enough has been said to show that the discharges must receive the most careful attention. Every discharge ought to be disinfected with strong substances liberally used; the best are carbolic acid (in large quantity), perchloride of iron, chloride of zinc, chloride of lime, or, if none of these are at hand, good quicklime. Although the results of disinfection of the discharges have not hitherto been encouraging, the plan has seldom been completely tried. All latrines should be disinfected, sewers flushed, carbolic acid poured down them, and every means taken to keep them ventilated.

What should be done with the disinfected discharges? Should they be allowed to pass into sewers, or buried in the ground? They must in some way be got rid of. Sewers certainly afford an easy mode of disposing of them; and as the discharges are mixed with much water, and are rapidly swept away in them, and as the temperature of the sewers is low, and decomposition is delayed, it is quite possible that sewers may be a means of freeing a town from choleraic discharges more easily than any other plan. And it appears to be a fact, that in the well-sewered towns in England the cholera of 1865 and 1866 never attained any wide spread. In Munich, in the cholera epidemic of 1873, the well-sewered parts of the town had only one-half the sickness and mortality of the others, which were either imperfectly drained or not at all.' In large towns, also, there are no other means of disposing of the discharges. But may not sewers be a means of dissemination, and thus, as in some outbreaks of enteric fever, be a source of danger? And again, when sewerage is poured over land, as it will be soon throughout all England, are we quite sure that no choleraic effluvia will pass off, or that the choleraic particles passing into the ground may not develop there, as Pettenkofer supposes is the case? There are no facts to enable us to decide, but the possibility of mischief arising in this way should, at any rate, make us still more urgent in the use of disinfectants to all discharges.

2

Again, as to disposal in the earth, if Pettenkofer is correct, that a loose moist earth is the place where the supposed germ of cholera acquires its power, the last place we should put a choleraic discharge would be the earth; and there would be even an argument against the use of the earth plan of dealing with sewage. Still, as there is much to be said against Pettenkofer's views, and as in small towns and villages there is only the alternative of allowing the discharges to pass into cesspools or streams, or to be disposed of in the earth, it would seem to be the safest course to deeply bury all disinfected discharges, care being taken to place them at a distance from houses and from sources of water supply. Another plan would be to mix them with sawdust and burn them.

That linen and bedding should be carefully disinfected, needs no argument. In some English towns all cholera clothing has been burnt, but whether this measure is necessary or not is uncertain. But thorough steeping and boiling before washing is essential, as washerwomen have certainly suffered in many cases.

3. The introduction of the agent by the medium of the air is generally

Soyka, Deutsche Viertlj. f. Off. Ges., Band xiv., Heft 1, p. 54, 1882.

2 That these may be so, in a particular way, was shown to be probable in Dr. Parkes' Report on Cholera in Southampton (Sixth Report of the Medical Officer to the Privy Council, p. 251); but still there is very little evidence on this point.

admitted, on the plea that cases occur in which any other mode of entrance is impossible. It is also held by some that, existing in the air, it can be carried for great distances by winds; and some observers indeed believe this to be its usual mode of transit, though this opinion appears opposed to all we know of its spread.

Without attempting to decide the point or to state the limits of the transmission, it is a matter of prudence to act as if the winds did carry the poison. The Indian rule is to march at right angles to the wind, and never against it or with it if it can be avoided. The spreading by the winds in India has been usually ascribed to the custom of throwing all the cholera evacuations on the ground; there they get dried, and then are lifted by the wind and driven to other parts. This seems probable, but no decided proof has been given; and an argument against it may be raised on the difficulty of accounting for the immunity of adjacent places if such transmission were common. So also the use of aërial disinfectants in cholera is rendered imperative by the chance that the cause may be in the air. use of sulphur fires has been advocated and tried in India, apparently with good effect (Crerar). The Vienna Conference affirmed transmission by the air, but only to a short distance, and never faster than man travels. They also recognized the great safeguard afforded by deserts, as the disease has never been known to be imported into Egypt or Syria across the desert by caravans from Mecca.1

The

4. The occasional, perhaps frequent, introduction by water seems certain. It was unanimously affirmed at the Vienna Conference, even by Pettenkofer, who has, however, since abandoned this view. It is a good plan always to change the source of supply, to use rain-water if no other fresh source is procurable; and in every case to boil, and filter, and to use also potassium permanganate." It remains yet uncertain whether a water which gives cholera is always chemically impure, or whether the choleraic matter may be in so small a quantity as to be absolutely indetectable. In the two cases examined by Dr. Parkes in which the water was the cause, it was highly impure. In India it is now ordered that all the water should be boiled.'

5. The introduction by food has been noted in some cases (although the Vienna Conference decided, by 11 to 7, that present facts do not warrant a decision). Every article of food, solid and liquid, should therefore be passed in review, and the cooking arrangements gone over step by step.*

'On this point the history of Chili is interesting, as cholera has never reached it. It is separated on the north from Peru by the desert of Attacama, and from the Argentine Confederation on the east by the Andes range, to which circumstances its immunity hitherto from epidemic diseases has been ascribed by the inhabitants.

* In the very able Report on Epidemic Cholera in the United States Army (Circular No. 5, War Department; Surgeon-General's Office, Washington), is what appears to be a good instance of the effect of changing the supply. At New Orleans rain, and in some cases distilled water, was supplied instead of river water, with the apparent effect of checking the spread (p. xvii.); see also the cases of Utrecht and Rotterdam, as reported by Buys-Ballot.

3 G. O. C. C., No. 192, clause 53. Förster, of Breslau (Die Verbreitung der Cholera durch die Brunnen, 1873), urges two recommendations which he thinks will prevent cholera in the future-1st, Lead to every town, even if at great cost, abundant and pure water, as indeed was done, he says, much better 2,000 years ago than now. 2d, Protect the ground from contamination in any way from excrement, and banish all cesspits. The ground must be absolutely pure, and this can only be if all fecal matter is removed to a distance.

• See Dr. Fairweather's Delhi case in the Sanitary Report of the Punjab for 1871; also given in Report on Hygiene, in the Army Medical Report, vol. xiii. (1873).

6. The localization of cholera is a marked feature in its history.' It is often as marked as in yellow fever, and may be confined to a very small area. At other times, in India, the "tainted district" may be of some extent. From this fact of localization arises the important rule of always leaving the locality when practicable, and in a large town of clearing out the house where cholera has happened. In India the present rule is to march the men out and encamp in a healthy spot at some little distance, changing the encamping ground from time to time. On the whole, this has acted well, and should be adhered to, though occasionally it has failed, generally, however, it would seem, from error in choice of locality. The men should be tented; the tents should be well ventilated, and often struck and repitched; an elevated spot should be chosen, and damp and low soils and river banks avoided. Orders lay down with precision the exact steps to be taken by a regiment when cholera threatens. of marching out must, of course, be subject to some exceptions. It has been advised that it should not be done in the rainy season in India. This must depend on the locality. It appears sometimes to have answered well, even in heavy rains; but in other cases the rains may be too heavy. No absolute rule can be laid down; but the circumstances which are allowed to set aside the grand rule of evacuation of a tainted place should be unequivocal.

This rule

In connection with change of locality, the opinions of Pettenkofer should be borne in mind. Pettenkofer believes that, of all conditions, the effect of soil is the most important. It is necessary, then, to consider particularly the nature of the soil where the fresh camps are to be placed, and to select perfectly dry and, if possible, pure, impermeable, uncontaminated soils, and to prevent the cholera discharges from percolating through the ground.

7. Men sick from cholera are also best treated in well-ventilated tents, whenever the season admits of it. Even in cold countries, up to the end of October or the middle of November, tents can be used if properly warmed. In India it should be a rule to treat every cholera patient in a tent, as far as circumstances permit it.

Internal Causes.-General feebleness of health gives no predisposition, nor is robust health a safeguard; some even have thought that the strongest men suffer most. Great fatigue, and especially if continued from day to day, greatly predisposes; of this there seems no doubt. No certain influence has yet been traced to diet, although it has been supposed that a vegetable diet and alkalinity of the intestinal contents may predispose. It

1 Surgeon P. Cullen (Indian Medical Gazette, July 1, 1873) notices a very singular case of localization at Etarsi.

2

* The order in India is, if a single case occur in a barrack, to vacate that part of the barrack, and to encamp the men in the cantonment. If a second case occur among the body of men thus removed, they are again moved, and the building or tent is vacated and purified. If a third case occur in this body of men within a week, they are removed to the preparatory camp.

Buildings are purified by scraping and washing walls with hot caustic limewash; boiling punkah fringes, ropes, curtains, etc., and using chloride of lime or other disinfectant. Tents are purified by being fumigated with either chlorine, nitrous acid, or sulphurous acid, and then exposed to the weather for ten days. Railway carriages, after occupation by troops carrying cholera, are purified by washing with boiling water containing in each gallon a wineglassful of carbolic acid, and burning sulphur in the closed carriages for two hours. If troops are moved by rail, they are not to use latrines, but trenches are to be dug for them (G. O. C. C., No. 193).

There are many instances of the effects of long marches. See Orton, Lorimer, and Thom, quoted in Brit. and For. Med. Chir. Rev., July, 1848, pp. 85-87.

does not appear that insufficient diet has any great effect, though there is some slight evidence that scurvy increases the mortality, and perhaps the predisposition. The strictest temperance does not preserve from attacks ; but every one agrees that spirits are no protection, and that debauchery increases liability.

Of pre-existing diseases, it has been supposed that cardiac affections and pulmonary emphysema predispose; the evidence is very unsatisfactory. If Beale's observations be correct, post-mortem examinations often show previous affection of the villi and mucous membranes of the intestines generally ; but it is very desirable there should be more proof of this.

Diarrhoea predisposes, and any causes which lead to diarrhoea, especially impure water, dietetic errors, etc., should be carefully looked after.

With regard to prophylactic measures (except in respect to proper diet, free ventilation, and pure water) nothing has yet been made out. Quinine has been recommended, and should certainly be given, especially in malarious countries, as it is a fact that the choleraic poison and malaria may act together, and even give a slight periodical character to choleraic attacks, which is never seen in non-malarious districts, and is therefore merely grafted on cholera. Peppers, spices, etc., have been used; but there is no good evidence respecting them. All diarrhoea should be immediately checked, and this is well known to be the most important point connected with the prevention of the internal causes. The universal order in India is, that any man going twice in one day to the latrine should report himself; and non-commissioned officers are usually stationed at the latrines to watch the men. The reason of this rule should be fully explained to the men. In two attacks of cholera in India, Dr. Parkes found it almost impossible to get the men to report themselves properly; the slight diarrhoea of early cholera is so painless that they think nothing of it. In England and Germany house-to-house visitation has been found very useful."

For some evidence as to scurvy, see Pearce and Shaw "On the Cholera of the Jail at Calicut," Madras Medical Journal, July, 1863.

* Several points have been taken from Mr. Dickinson's useful little pamphlet on the Hygiene of Indian Cholera, 1863.

Great importance has been attached to the meteorological condition attending outbreaks of cholera; they do not appear to be very important, except in two or three

cases.

1. Temperature.-A high temperature favors the spread by increasing the putrefaction of the stools, and by augmenting generally the impurity of the air. When cholera has prevailed at a low temperature (it has been severe at a temperature below freezing), the drinking-water has possibly been the cause.

2. Pressure has no effect. The old observation of Prout, that the air is heavier in cholera epidemics, has never been confirmed.

3. Moisture in Air.-Combined with heat, this seems an accessory cause of impor tance, probably by aiding transmission. Moisture in the ground, combined with heat of the soil, has always been recognized as an aiding cause of great importance. 4. Dryness of Air seems decidedly to check it.

A

5. Rain sometimes augments, sometimes checks it. This, perhaps, depends on the amount of rain, and on whether it renders the drinking-water more or less pure. very heavy rain is a great purifier.

6. Movement of Air.-It is certainly worst in the stagnant atmospheres, as in the cases of all the specific poisons.

7. Electricity is not known to have any effect. This was particularly examined by Mr. Lamont in Munich, one of the most celebrated physical philosophers of our time, but with entirely negative results.

8. Ozone has no effect, either in its presence or absence (Schultze, Voltotine, De Wethe, Lamont, Strambio, Wunderlich).

Typhus Exanthematicus (Spotted Typhus).

2

External Cause.-An animal poison, origin unknown, but communicable from person to person, probably through the excretions of the skin and lungs floating in the air. Not known to be communicated by water or food. Its spread and its fatality are evidently connected with overcrowding and debility of body from deficient food. That it can be produced by overcrowding is yet uncertain. The preventive measures may be thus shortly summed up: Adopt isolation of patients; use the freest ventilation (5,000 to 6,000 cubic feet per head per hour or more); evolve nitrous acid and chlorine fumes; thoroughly fumigate with sulphurous acid, heat (to 220° Fahr.), wash, and expose to air all bedding (including mattresses) and clothes. This last point is extremely important. In fact, it may be said that, for the prevention as well as treatment of typhus, the cardinal measures are abundance of pure air and pure water. Whenever practicable, treat all typhus patients in tents, or wooden huts with badly joined walls, not in hospitals. Fumigate tents and scrape and limewash huts, and remove earth from time to time from the floors. A number of typhus patients should never be aggregated; they must be dispersed ; and if cases begin to spread in an hospital, clear the ward, and then, if the disease continues, the hospital itself; then wash with chloride of lime, and then limewash or scrape walls and floors, and thoroughly fumigate with nitrous acid. It has been often shown that even exposure to weather, bad diet, and insufficient attendance are less dangerous to the patients than the aggregation of cases of typhus.

Internal Causes.-A special condition of body is necessary, as in the case of small-pox, and one attack protects to a great extent from another. The nature of the internal condition is unknown; but general feebleness from bad diet, overwork, exhaustion, and especially the scorbutic taint, greatly increase the intensity of the disease in the individual, and perhaps aid its spread. These conditions, then, must be avoided. But the strongest and best health is no guarantee against an attack of typhus.

Bubo or Oriental Plague (Pali Plague in India).3

The preventive measures should be the same as in typhus, to which this disease shows great analogy. The history of the plague at Cairo (from which it has been now banished for many years, simply by improving the

During the French war of 1870, although there was much crowding, wretchedness, and misery in Paris, and particularly in Metz, there was but little typhus; it was nothing like the amount in the first Napoleon's time (Grellois, Histoire Médicale du Blocus de Metz, 1872, Chauffard, Académie de Médecine).

2

By the term isolation is meant the placing a patient in a separate building, not in another room in the same building; in the case of small-pox, typhus, and scarlet fever, this partial isolation, though sometimes successful, cannot be depended upon. If a room must be chosen in the same building, choose the top story, if a room can be there

found.

3 The Pali plague (Maha Murree), which was most common in Rajpootana, was evidently propagated by the filthy habits of the inhabitants (see Ranken and others), and was some years ago almost entirely got rid of by sanitary measures. Subsequently, these were neglected, and the disease returned. It has now again greatly lessened. Hirsch has pointed out that the Pali plague differs from the Egyptian plague in having a marked lung disease, and in this it resembles the black death in the fourteenth century, with which Hirsch, in fact, considers it identical.