RESUMÉ.

1. Tuberculosis is an infectious disease.

2. The breath of the consumptive patient is not infectious.

3. The sputum is harmless as long as it remains moist.

4. Tuberculous infection is produced, in the great majority of cases, by the inhalation of dried and pulverized tuberculous sputum.

PREVENTION.

THE RESTRICTION OF INFECTION.

It should be impressed upon consumptive patients and other persons living with them, that the sputum (what they cough up) is dangerous, and must be properly disposed of. It should be received in a spit-cup or spittoon containing a little water or disinfecting fluid, and must never be spit upon floors, carpets, or received in handkerchiefs. If a disinfecting solution is used, corrosive sublimate is unsuitable; chloride of lime is efficient but irritates the air passages; carbolic acid with five per cent of tartaric acid or hydrochloric acid, will be the best disinfectant generally available. If, occasionally, it is necessary to have handkerchiefs or cloths soiled with the sputum, they should be boiled as soon as possible, and before drying. The spittoon should be of such shape that the sputum may easily fall into the water without soiling the sides of the vessel. For patients not able to sit up, a small spit-cup with a handle should be used. When flies are present it should be covered. Spit-cups and spittoons should be emptied and cleansed often with boiling water and potash soap. When the house has a drainage system, the contents may be poured down the water-closet or slop-hopper; when it has not, they should be buried in ground which will not be turned up soon.. The sputum should not be thrown out upon the surface of the ground near inhabited places, nor on manure heaps, nor where animals may get it, nor where it may soil animal food. Boxes filled with sand or sawdust should not be used. Cheap wooden and pasteboard spit-cups are now on the market, one of which may be burned daily, or oftener, with its contents, as a convenient way of disposing of the sputa. A pocket spit-flask of small size has been devised, which may be used while away from home.

The floors, woodwork, and furniture of rooms in which consumptive patients stay, should be wiped with a damp cloth, not dusted in the usual way. The patient's clothing should be kept by itself, and thoroughly boiled at the washing. The patient should be made to understand that in neglecting these measures he is imperiling his friends and at the same time diminishing very much his own chances of recovery by re-infecting himself with the inhalation of his own dried and pulverized sputum. After a death from this disease has occurred, the patient's room, clothing, and bed should be disinfected. For this purpose boil all bed and personal clothing, or disinfect them, while practicable,

in a steam disinfector; wash furniture, woodwork, walls, and floors with carbolic acid solution and thoroughly expose.the rooms to light and air.

If raw milk is used as food, especially if it is to be given to children, an assurance should be had that the cows which produce it are perfectly healthy and subjected to healthful treatment. When there is any doubt as to the health of the cows which furnish the supply, the milk should be boiled before use. Thorough cooking will remove all danger of tuberculosis through the medium of the meat supply.

Tuberculous mothers and those inclined to consumption should, under no conditions, nurse their babies.

TO GUARD AGAINST CONTRACTING THE DISEASE.

By observing the rules which are expressed and suggested in the foregoing, the principal, if not all, danger from infection may be avoided.

Whatever has a tendency to undermine the general health increases the susceptibility to the infection and diminishes the power of recovery from incipient tuberculosis. A fact abundantly shown in the dissecting-room is that many persons, dying of other diseases, have had tuberculosis, and have recovered in its early stages. This tendency to recover is greatly strengthened by the habitual breathing of pure air. Means should be provided for the abundant ventilation of inhabited rooms, particularly of sleeping-rooms, schoolrooms, and churches. The open-air treatment of consumptives, and those who are threatened with tuberculous disease, has given much better results than any other. Particularly in Germany, and to some extent in this country, such treatment has been systematized in "sanitaria" for consumptives. Here the patients have the advantage of a regular life, nutritious food, and such exercise as they can bear without fatigue; but the chief curative agent is an abundance of fresh air. Even in the coldest of winter weather, patients, after a period of gradual habituation, and always guided by the judgment of the physician, pass the whole day walking in the open air or sitting or lying on resting places, wrapped comfortably in blankets. Usually no claim is made for advantages of climate. An abundance of pure air is the all-important thing.

HOW FAR MAY A COW BE TUBERCULOUS BEFORE HER MILK BECOMES DANGEROUS AS AN ARTICLE OF FOOD?*

BY HAROLD C. ERNST, A. M., M. D., OF BOSTON.

The change of opinion in regard to the infectious nature of tuberculosis has been very marked in the last few years, not among the scientists, but among the people at large. Of course the medical world has, as a rule, accepted the conclusions to be drawn from Villemin's work of twenty-five years ago, and the discovery of the specific cause of the disease by Koch has only added strength to the theories advanced in certain quarters before that time. The change of opinion spoken of is, after all, hardly a change, but, more properly, an acceptance of the knowledge gained in regard to the disease by the more recent and exact methods of research, and a much wider diffusion of that knowledge. More and more is it the rule that the knowledge of the transmissibility of tuberculosis by means of infected material is recognized among those whom it concerns the most, and nothing but good can come from the diffusion of that knowledge.

It is hardly too much to say that proper methods of management of tuberculosis, both in human beings and in animals, involve more important interests- pecuniary as well as vitalthan any other subject that engages the attention of medical men. It is well known that one seventh of the human race, approximately, perish from this disease, and when we acknowledge to ourselves, as a fair review of the evidence at hand must force us to do, that most, if not all, of this loss is preventable, our duty is plain before us; that is, never to cease speaking of it, never

* Read before the Association of American Physicians, Washington, September 20, 1889, and published in the "American Journal of the Medical Sciences" for November, 1889. Permission has been obtained of the author to reprint the paper in this report.

to give up trying to reconcile the money interests of man with his own welfare, and to do all in our power, by the collection of clinical and experimental evidence, to make the case complete.

The work showing the etiological relationship of the bacillus of tuberculosis to the disease was, to all intents and purposes, complete upon the publication of Koch's monograph upon the subject. Nothing more in the way of proof was actually needed, and, indeed, very little has been furnished. At the same time, confirmatory evidence was demanded by some who had and many who had not access to the original details, and this confirmatory evidence has been furnished in such overwhelming amount that it is to-day but a waste of time to repeat, what is accepted the scientific world over, that in the organism described by Koch we have the specific cause of this pathological change, and that without its activity we do not have tuberculosis in any form or under any conditions.

An imperfect understanding of the nature of bacteria in general, and of this organism in particular, has led to many attempts to arrest the pulmonary form of the disease it produces, by therapeutic measures, most of which would have been seen to be useless at the outset, if a knowledge of the problem had been complete. It is not upon drugs or mechanical means that our reliance should be placed in attempting to stamp out this scourge of civilized man. Our attention must be turned in the direction of proper preventive measures, and until the necessity for this is impressed upon physicians in general, and by them upon the people at large, so that the preventive measures suggested after mature deliberation will be complied with, but little can be effected, and the knowledge gathered after so much hard labor must be considered as wasted, for the time being.

In order to the suggestions upon which the stamping out of tuberculosis must depend, there is necessary a large amount of investigation into the methods by which it spreads and by which the virus is carried from person to person. Among these methods are undoubtedly the excreta-more especially the sputum from persons affected with the disease; the excreta are carelessly treated, and scattered broadcast, to the injury of persons susceptible but not previously affected. The methods of distribution

in this way, and the behavior of the bacillus of tuberculosis outside of the body, have been well and recently treated by Cornet (Zeit. f. Hyg., Bd. v. S. 191, 1888).

Other methods of distribution are of importance, however, and until within a few years have not received attention from the medical profession at all commensurate with their value. These methods of infection are those arising from the ingestion of food materials coming from the domestic animals, especially the flesh and milk of cattle.

In Koch's Etiology of Tuberculosis he uses the following expressions:

"Since by far the greatest number of cases of tuberculosis begin in the lungs, it is to be supposed that the infection in all these cases has taken place in the manner just suggested,- by the inhalation of phthisic sputum dried and made into dust. The second principal source for the tubercle-bacilli, viz., tuberculosis of the domestic animals, appears not to have anything like the importance of the phthisic sputum. The animals, as is well known, produce no sputum, so that during their life no tuberclebacilli get from them into the outer world by means of the respiratory passages. Also in the excrement of tuberculous animals the bacilli appear to be only exceptionally present. On the contrary, it is a fact that the milk of tuberculous animals can cause infection.

"With the exception of this one way, therefore (i. e., through milk), the tuberculous virus can only have effect after the death of the animal, and can only cause infection by the eating of the meat. The same conditions hold for the milk of cows suffering from 'perlsucht.' Before all things, if infection is to take place, it is necessary that the milk contain tubercle-bacilli; but this appears to be the case only when the milk-glands themselves are affected with the disease. This explains at once the contradictions in the statements of various authors who have made feeding experiments with the milk from cows suffering from 'perlsucht." If infection from tuberculous animals does not appear to be frequent, it must by no means be underrated."

This caution is one which was necessary at the time it was written, and its repetition is as necessary now as ever. What conclusions may be reached in regard to its extreme importance,.