One more consideration. If the exclusive use of vegetable food will prevent a multitude of the worst and most incurable diseases to which human nature, in other circumstances, seems liable; if it will modify the diseases which a mixed diet, or absolute intemperance, or gluttony had induced,--by what rule can we limit its influence? How know we that what is so efficacious in regard to the larger diseases, will not be equally so in the case of all smaller ones? And why, then, may not its universal adoption, after a few generations, banish disease entirely from the world? Every person of common observation, knows that, as a general rule, they who approach the nearest to a pure vegetable and water diet, are most exempt from disease, and the longest-lived and most happy. How, then, can it otherwise happen than that a still closer approximation will afford a greater exemption still, and so on indefinitely? At what point of an approach toward such diet and regimen, and toward perfect health at the same time, is it that we stop, and more temperance still will injure us? In short, where do we cross the line? IV. THE POLITICAL ARGUMENT. I have dwelt at such length on the physiological and medical arguments in defence of the vegetable system, that I must compress my remaining views into the smallest space possible; especially those which relate to its political, national, or general advantages. Political economists tell us that the produce of an acre of land in wheat, corn, potatoes, and other vegetables, and in fruits, will sustain animal life sixteen times as long as when the produce of the same acre is converted into flesh, by feeding and fattening animals upon it. But, if we admit that this estimate is too high, and if the real difference is only eight to one, instead of sixteen to one, the results may perhaps surprise us; and if we have not done it before, may lead us to reflection. Let us see what some of them are. The people of the United States are believed to eat, upon the average, an amount of animal food equal at least to one whole meal once a day, and those of Great Britain one in two days. But taking this estimate to be correct, Great Britain, by substituting vegetable for animal food, might sustain forty-nine instead of twenty-one millions of inhabitants, and the United States sixty-six millions instead of twenty; and this, too, in their present comfort, and without clearing up any more new land. Here, then, we are consuming that unnecessarily--if animal food is unnecessary--which would sustain seventy-nine millions of human beings in life, health, and happiness.