The causes of smallpox, I said, were unconsidered in Cobbett’s days. It never even entered into Jenner’s head that the disease might be a consequence of bad conditions of life; nor did he try to explain why the malady was on the decrease ere he appeared with his magical prescription. The decrease was claimed for vaccination, but it had set in before vaccination was heard of, and was continued among those who never received it. No sanitary improvements had been effected to account for the abatement of the disease. To what, then, was it due? I answer, in part at least, to a progressive change in the diet of the people--to the substitution of tea for malt liquors, and to the displacement of arid fare by potatoes. The food of city folk up to the close of last century was closely akin to that of men at sea, and their scorbutic habit of body was notorious--a habit that rendered acute or chronic whatever disorders they were subject to. The remedy came of inclination and necessity rather than of intention. Tea was instinctively preferred by women, and the dearness of provisions compelled resort to the potato, easily grown and grateful to the palate as a mitigant of the saltness of beef, bacon, and fish. If any are disposed to dispute the fact of this revolution in the popular dietary, they may be referred to Cobbett. He witnessed the change, and persistently denounced it. Tea-drinking was to him an abomination. It was a slatternly indulgence, costly to the poor, and innutritious. Potatoes were as detestable. They were trash as compared with bread; wasteful, dirty, and unfit to satisfy a man’s appetite. It is true that tea and potatoes are poor forms of food, but the one as a substitute for beer, and the other as an antiscorbutic, were eminently useful. It is not said that smallpox is caused or prevented by food, proper or improper, but that the character of food may predispose to disease, and intensify it; as is manifest on ship-board. Hence it is (in the absence of other adequate influences) that I am disposed to ascribe the abatement of smallpox which set in toward the close of last century to the better blood of the people ameliorated by that increased consumption of tea and potatoes, against which Cobbett so blindly and vainly testified.