Mr. Malthus, and those who agree with him, have {245}generally referred to the United States, as a country in which the human race increases in a ‘geometrical ratio, and have fixed on twenty-five years as the term in which the population of that country doubles itself. Mr. Sadler contends that it is physically impossible for a people to double in twenty-five years; nay, that thirty-five years is far too short a period,--that the Americans do not double by procreation in less than forty-seven years,--and that the rapid increase of their numbers is produced by emigration from Europe. Emigration has certainly had some effect in increasing the population of the United States. But so great has the rate of that increase been that, after making frill allowance for the effect of emigration, there win be a residue, attributable to procreation alone, amply sufficient to double the population in twenty-five years. Mr. Sadler states the results of the four censuses as follows:-- “_There were, of white inhabitants, in the whole of the United States in 1790, 3,093,111; in 1800, 4,309,656; in 1810, 5,862,093; and in 1820, 7,861,710. The increase, in the first term, being 39 per cent.; that in the second, 36 per cent.; and that in the third and last, 33 per cent. It is superfluous to say, that it is utterly impossible to deduce the geometric theory of human increase, whatever be the period of duplication, from such terms as these._” Mr. Sadler is a bad arithmetician. The increase in the last term is not, as he states it, 33 per cent., but more than 34 per cent. Now, an increase of 32 per cent, in ten years, is more than sufficient to double the population in twenty-five years. And there is, we think, very strong reason to believe that the white population of the United States does increase by 32 per cent, every ten years. {246}Our reason is this. There is in the United States a class of persons whose numbers are not increased by emigration,--the negro slaves. During the interval which elapsed between the census of 1810 and the census of 1820, the change in their numbers must have been produced by procreation, and by procreation alone. Their situation, though much happier than that of the wretched beings who cultivate the sugar plantations of Trinidad and Demerara, cannot be supposed to be more favourable to health and fecundity than that of free labourers. In 1810, the slave trade had been but recently abolished; and there were in consequence many more male than female slaves,--a circumstance, of course, very unfavourable to procreation. Slaves are perpetually passing into the class of freemen; but no freeman ever descends into servitude; so that the census will not exhibit the whole effect of the procreation which really takes place.