One of the most curious questions in morals, politics, and physiology, is started by these facts. They furnish food for thought. One class of speculators will find moral causes to explain the circumstances, and they may easily gather a pile of facts to sustain their positions. Climate, too, has its influence. The civil government, with the physical condition of the people, is to be considered. But when the physical, the moral, the civil, and the social state of Austria, Spain, France, Holland, Prussia, Italy, and England is duly examined, it still remains to be ascertained why it is that the number of inhabitants increased more rapidly among the colored people of the Southern States of North America while they were slaves, and now increases more rapidly among the Irish portion of the American population, than it does among these highly favored countries of Europe. The statistics of births in New England and other parts of the United States unhappily show that, with the increase of the cost of living, and of luxury and effeminacy, the number of children born is less and less from year to year. There is no truth in social economy better established by the comparison of an adequate number of facts than this, that the diminution in the number of births is attended by, if not consequent upon, the deterioration of the health and the morals of any people. Oppression which makes a wise man mad may depress the spirits, exhaust the energies, and retard the increase of a population, not supernaturally sustained as were the Hebrews in Egypt, who, the more they were afflicted, the more they multiplied and grew. But favored as the middle and southern countries of Europe are by climate and soil, affording the people an easy and comfortable subsistence, they might and would increase in numbers as rapidly at least as the northern, if they were so disposed.