A stationary or declining population throughout Europe sometime after the return of peace is a possibility. But this does not destroy the significance of the fact that there is in herent in humanity a great potential power of increase, the realization of which would be disastrous, the limiting of which • Estimate of Sussmilch, the famous statistician of the eighteenth century.
• Estimate of Levasseur, cited by Willcox.
either by crude objective means (famine, war, illicit measures) or by violitional means is inevi table. It does not disprove the great biologic proposition in the Malthusian doctrine.
§ 3. Increase since 1790 in America. The growth of the population of the United States since 1790 (the date of our first census) has been proportionally much greater than that of the European countries. But it has been in two respects different from theirs, and abnormal : in be ing so greatly aided by immigra tion (while many of them lost greatly by emigration) ; and in spreading over wide new areas of land, almost uninhabited before, instead of merely increasing the density of population on the same area of land.7 The population the first three decades increased almost en tirely extensively, moving toward an ever-widening frontier, spreading itself over a great territory. Twice did great ad ditions of territory cause the average density to decrease (1800-1810 and 1840— 1850). Cities, meantime, were growing, and decade by decade from 1850 on the growth of population was in nature more inten sive. The increase in the number of persons per square mile in the first thirty years was almost nil, .7 of a person; in the second (1820-1850) was 2.4 persons; in the third (1850-1880) was 9 per sons ; and in the last (1880-1910) was 14 persons per square mile. The increase in density was 20 times as fast in the last thirty as in the first thirty years, having almost doubled be tween 1880 and 1910. A large part of our area is desert, greatly inferior to the sandy northern plains of Europe, and a large part is barren mountain (the Rockies), greatly in ferior to the well-watered Alps, as a place for human habita * The first rate shown is for the decade ending 1800, the last, 1910. The average rate for the whites until 1880 was around 35 per cent, but the trend since has been downward until in the last two decades it has been less than % as high as it was then; it would be much less but for the very large European immigration.
The rate of increase of the negroes has been less than that of the whites in every decade but one, and the trend of the rate has been downward since 1810. It now is about % of what it was in the begin ning, and practically the whole of the increase is now due to the South Atlantic and South Central divisions. Elsewhere the negro population would be either stationary or decreasing in numbers but for the migra tion from the southern states (and some from the West Indies).
tion. Still the population of the United States is sparse compared with the countries of Europe.
§ 4. Relation of population to resources. We can ac count for this wonderful growth of population throughout the world only in the light of the increased power of pro duction of wealth. The population of different countries, and of different sections of a country, is seen to bear a general relation to their resources. A community with a poor soil, little wealth, and no machinery is doomed to remain few in numbers. Mountains, districts poorly watered, the frozen regions of the North, are sparsely populated because natural resources are lacking. If food production alone is thought of there are apparent exceptions to this statement, but there are no absolute contradictions of it. A favored harbor may make possible a flourishing commerce on a rocky coast; an infertile soil may support a large population when great deposits of coal or iron insure, by exchange, great food-supplies. Pro ductivity must be measured under modern conditions by the purchasing power that is possible in the environment.
The whole world has been coming more into the condition of political security, settled industry, and improved methods of production. The result has been a great reduction in the extent and severity of famines, an increase of the real in comes of the masses, and the survival of large numbers of people, young and old, who formerly would have been cut off. The increase of wealth, made possible by the new condi tions, has gone largely to increase the number of people. The biologic factor in population is great and ever present.