Luxury commences when trade and arts have been carried to a considerable degree of perfection. It is even a stronger check on population than destitution, though acting on a smaller class. Its artificial habits, its irregular occupations, its indolence, its self-indulgence, all combine to weaken the forces of reproduction. Rarely indeed would patents of nobility and entailed estates fall in, if committed to the inhabitants of the cottage rather than of the castle.

3d, We have that class of influences which are found in vicious habits and unwholesome occupations. The sure results of these are to check propagation, a most beneficent provision of nature. In a marked degree is this true of those occupations which, by heated air, by poisonous exhalations, by cramping postures or excessive labor, dwarf and distort the functions of the body. The same causes most mercifully defeat the powers of reproduction. It is well that it should be so; that, if these places must be filled, fresh life may be poured into them from the hillsides, rather than that the course of health and strength should be downward without relief, falling faster every generation. For the effects of vicious courses, we need only cite those savage nations which, in every quarter of the globe, are disappearing so fast, not more by the pressure of civilization than by their own destructive habits.

4th, We have also that class of influences which come from misgovernment and war. These serve to retard the progress of population, though not necessarily to throw it backward. France under the old regime, England through her most sanguinary civil conflicts, still held on their way in wealth and numbers; but Campania by excessive taxation, Belgium by religious persecution, Germany in the Thirty Years' War, Prussia under the great struggles of Frederick, fell off widely in both respects. It really seems too bad to quote, but many writers have ventured to suppose that war was God's own method of restraining population! The money spent in any war would, ten times over, support all the men killed in it; if, indeed, the destruction of the able-bodied could be supposed to take any thing from the difficulty of subsistence, especially when their helpless dependants remain. How the war-system affects population may be shown in an instance. Nearly half a million of young men in France are required to serve in the army from the ages of eighteen to twenty-five. This embraces the period at which the occupations of life are usually chosen, marriage contracted, and domestic habits formed. At the end of their service, they are thrown out on society with the vices of the camp and the restlessness of military life, with no position in life secured, and no occupation learned. The results have been plainly visible in diminishing from year to year the ratio of increase in population.

5th, The fifth cause which we shall notice is altogether different in its origin and character. The others have all been on the brutal side of man, operating by misery and want. This works in alliance with the nobler part of his being, and is of a kind with reason. It is self-restraint. In a degree, indeed, a great part of the world exercises this. The Chinaman will rear as many children as he can find vermin for as food; but the Hindoo, through his religious faith, stops short of all animal food, and limits population by vegetable subsistence. And so almost all

nations have a point of decency below which they will not go. But the self-restraint of which we speak is of a higher kind, and begins to operate before the senses revolt in disgust or pinch in hunger. It is found wherever there is self-respect and social consideration. Hence the moderate increase of many countries where population maintains a just proportion to the general wealth, taste, and customs. As this is a subject to which belongs illustration rather than analysis, we give at length a remarkable example, which will also enable us to set in contrast the operation of the other causes. We take the State of Massachusetts, of which, let it be observed, only a very small class is influenced by luxury, and a smaller class even affected by destitution. Vice, war, and misgovernment certainly work as little injury here as in any portion of the world.

The annual registration, made with much care, shows the following result in regard to births among the native and foreign population in 1860: —

Native population, whole number of persons .... 970,952 Foreign „             „          „            „          .... 260,114*

Number of births in native population......................16,672

„            „ foreign „ ................... 16,138

The number of births in the native population, to be in proportion to the foreign, should have been 60,239, or nearly four times the actual number. The difference is very striking and suggestive. It may be accounted for in part by the following considerations: —

(1) A very considerable share of the foreign population consists of those under fifty years of age, and so generally able to contribute to the increase of population. How far this fact is operative may be seen in the statement, that, if all persons above fifty were removed from the native population, it would be diminished somewhat over one-sixth; that is, brought so much nearer the numbers of the foreign.

* Of these, 185,434 are from Ireland.