I think it capable of proof that it is on the scarcity of water, and on the habits and customs which have grown up during centuries of suffering from that scarcity, that the existence even of the "endemic area," the natural "home of cholera," depends. If this be admitted—and I think it can no longer be denied—the fact and necessary inferences from it are of vast and world-wide importance. The natives bathe and wash their utensils and clothes in the tank, because it is the only available place in which to do so, and they use the water of the tank, contaminated as it is in addition by soakage and sewage, for cooking and drinking, because it is the only water supply available for domestic purposes.
With these facts before us, and reading them in the light of our European experience, it can no longer be doubted by thoughtful and reasonable persons that the reason why, in India as in other places, some classes escape and others suffer, is that some drink pure water and others drink water contaminated with choleraic discharges.
Nor can we shut our eyes to the probability, growing stronger every year, that the true meaning of the term "endemic area," in regard to cholera, is a district in which the customs of the people sanction the drinking of fecally polluted water, and in which from temperature, and perhaps from other causes incompletely known, the cholera germ or contagium can easily keep alive and propagate itself in soil or water in the interval between its exit from one host and its entry into another.
Nothing seems more certain than that people can touch cholera patients, and rub them, handle them, and live with them, even in the midst of an endemic area, and not catch the disease so long as they take precautions not to swallow it.
This is the key to the position, the horrid truth, the dirty fact, that the bacillus, the contagium of cholera, lives two lives: one, in the human body, causing the disease, multiplying within the patient, and poured forth by him in abundance; the other, outside the body, waiting in damp ground, on soiled linen, in dirty water—waiting to be swallowed by some one else and to start again on its destructive course. How, then, does it get round? We know well enough that the outside of a cholera patient is not infectious; the infection comes from within, with the discharges; how, then, does it get into the alimentary canal? How can it get round except in what we drink?
This is what I mean by speaking emphatically of cholera being a water-borne disease. It is not that cholera is a disease of rivers and watercourses alone, but that, whether it is a matter of rivers or tanks or water supplies, or merely of wash-basins, jugs, and water-bottles, the water which the patient drinks is the vehicle by which the poison enters, and is the final step in the course of
