It is not generally known, although the fact has been sufficiently demonstrated by different vital statisticians, that great annual mortality is accompanied by a proportionate increase of births, so that the population is kept at its usual average even if it does not increase. One effect of this mortality and increase of births is the disproportion between the numbers of the young, the improvident, and the thoughtless, and the older, more prudent and considerate. Mr. Slaney, in his report on Birmingham and other towns, made to the commissioners for inquiry into the state of large towns and populous districts, after referring to Mr. Chadwick’s exposure of the popular fallacy, that the sufferings caused by disease, especially among the poor, restrained the increase of population, says: “I have constantly observed, wherever the mortality was high in close, narrow, neglected courts and alleys, there the children swarmed, as if to fill up the places; and it has been demonstrated again and again, that a high mortality in an increasing country, only leads to a great increase of births.” After this preliminary notice, the reader will be able to understand the force of the following remarks on the connection between mortality, (including, of course, its physical and moral causes,) and crime. Mr. Slaney contrasts the two classes or kinds of inhabitants of the same city, in the one of which the annual mortality is but two, and in the other four per cent. “We shall find the rate of mortality one great criterion of comfort, therefore, of contentment, of good conduct, of moral habits, of intelligence, docility, usefulness and value.”