humanity; thus, at the same time, supplying one of the most powerful predisposing causes of the disease, and fearfully augmenting the misery and danger of the affected. In such a state of things it would be impossible to persuade persons of character, like those who, without hesitation, undertook the duty of nursing the choleral patients in Haslar, to enter on similar service for eighteen-pence a day; nay, it might be impossible to persuade men to enter on such a forlorn hope by any consideration. Although the pro-contagionist might not be moved by facts and inferences like these, he would perhaps be disposed to ask the man propounding them, some such question as the following.—As you do not admit that contagion is the cause of cholera, what in your opinion is the cause? In return it would not be impertinent to say to the querist, what is the cause of ague? Something emanating from the surface of the earth, on the spot, or not far from the place where its subjects are resident?—something so subtle as to be imperceptible by the senses, and hitherto beyond the scrutiny of chemists and meteorologists. He would, it is presumed, answer in some such terms, or if he attempted any much more precise and instructive, he would proceed without the warrant of fact and experience. Such at least would be the general reply of the profession, and a more complete and unconditional confession of ignorance of every thing respecting the essence of a most powerful and wide spread cause of disease cannot be made. Though we know a good deal of the places most prolific in its production, as well as of the agents which co-operatively increase its force, we know it solely by its effects. In very similar, if not precisely the same terms, it seems to the writer, should the question, what is the cause of cholera, be answered. Little, if anything more can be affirmed respecting its origin, but almost every thing authentic in its history, progress, and phenomena, testify to its having a local source, and generally very limited scope of operation. Thus it appears simultaneously in different, distant places, leaving intermediate places untouched. It attacks in one town a particular district, street, or portion of street, beyond which it does not travel. In another town it shows itself among distant portions of the inhabitants, leaving long spaces unscathed. Again, while one town suffers severely from it, another in the neighbourhood has not a single case then, or thereafter; or the town which escapes this season, falls fatally under its sway the next, when all the rest of the country is clear. These and such circumstances as these, point as clearly as it is possible to point at the endemic source of cholera, although the _essential_ cause of the disease cannot be ascertained.