Another thing, in which Mr. Malthus attempted to clench Wallace's argument, was in giving to the disproportionate power of increase in the principle of population and the supply of food a mathematical form, or reducing it to the arithmetical and geometrical ratios, in which we believe Mr. Malthus is now generally admitted, even by his friends and admirers, to have been wrong. There is evidently no inherent difference in the principle of increase in food or population; since a grain of corn, for example, will propagate and multiply itself much faster even than the human species. A bushel of wheat will sow a field; that field will furnish seed for twenty others. So that the limit to the means of subsistence is only the want of room to raise it in, or, as Wallace expresses it, "a limited fertility and a limited earth." Up to the point where the earth or any given country is fully occupied or cultivated, the means of subsistence naturally increase in a geometrical ratio, and will more than keep pace with the natural and unrestrained progress of population; and beyond that point, they do not go on increasing even in Mr. Malthus's arithmetical ratio, but are stationary or nearly so. So far, then, is this proportion from being universally and mathematically true, that in no part of the world or
