In taking a general review of that department of human society, classed under the name of savage life, the only advantage Malthus notices is the possession of a greater degree of leisure by the mass of the people, than that possessed by those of civilised countries. “There is less work to be done, and, consequently, there is less labour. When we consider the incessant toil to which the lower classes, in civilised societies, are condemned, this cannot but appear to us a striking advantage; but it is probably overbalanced by greater disadvantages.” This remark of Mr. Malthus shows us, to a certain extent, on what J. J. Rousseau founded his belief as to the superior happiness of the state of nature over the civilised. Had Rousseau read the Essay on Population, he could not, we believe, have failed to perceive that the evils of civilisation are almost solely due to the universal want of knowledge of the Population Law. The late marriages, and prostitution, so bitterly inveighed against by that author, are merely the sorrowful population checks of most modern civilised nations, that have passed into the pastoral and agricultural stages of society, and have not yet proceeded far enough to control the enormous fecundity of the race by less painful and more thoughtful expedients than those which Jean Jacques Rousseau so clearly perceived and so powerfully denounced in the French society of the reign of Louis XV. After speaking of the positive checks to population which have been so universal among savage nations, Mr. Malthus proceeds in chapter vi. to treat of the checks which prevented increase among the ancient inhabitants of the North of Europe. Astonishment has often been expressed at the hordes of warriors that, at various periods of the decay of the Roman Empire, were poured down upon it from the Northern nations. Mr. Malthus explains, with great clearness, that, wherever the customs of such nations as composed the immigrants were such as to conduce to health and early marriage, the immense fecundity of the race fully accounts for these crowds of immigrants so rapidly succeeding each other until the destruction of Rome ensued. Machiavel, in the beginning of his _History of Florence_, says: “The people who inhabit the northern parts that lie between the Rhine and the Danube, living in a healthful and prolific climate, often increase to such a degree, that vast numbers of them are forced to leave their country and go in search of new habitations. These emigrations proved the destruction of the Roman Empire.”