As W3 reach the conclusion of our subject we cannot but feel the inadequacy with which we have treated the theme which has occupied us. The portion of man's nature whose laws and liabilities we have with great brevity rehearsed, is at once the most mysterious and the most momentous of all. This alone it is which allies him with an earthly future beyond the limit of his own existence ; this it is which in its use or abuse controls not solely his own life and welfare, but in ways and to an extent wholly beyond our power to estimate, the welfare of generations to come.

Whether we regard the subject from a purely ethical or a purely physiological point of view, its importance cannot but impress us profoundly. What impulse of man's physical nature most potently governs his actions, his aspirations, and the moral complexion of his life ? Precisely this on which we have been engaged. On what do some of the most difficult questions of modern social morality turn ? Once more, on the control of this impulse. How can we as individuals most certainly secure the moral progress of posterity ? By endowing them with a physical constitution free from the taint of hereditary disease, and a mental con. stitution devoid of inherited tendencies to crime. To accom-piish this, science warns us again and again that no subtle compound of chemicals will suffice, and no future reformation and late adopted purity of life, but only early, unalterable, permanent fidelity to principle.

The hesitancy which has so long, and so naturally kept silent the voice of the medical profession upon these points, should now be laid aside, for the immense collection of statistics leave no doubt as to their accuracy, and their bearing on the future of the race. Many of the best minds in the world of practical and statistical medicine have been earnestly turned in this direction, and, as a consequence, during the last decade great advances in knowledge have been secured, and numerous suggestions have been presented looking to the preservation of the general health. It is not possible for the profession alone unsupported by the public, to carry out those measures of repression and protection, which we have referred to as necessary to effect any reform. And the public, in order to be induced to take any action, must be made acquainted in no uncertain manner with the necessities of the measures asked of it.

Finally, the private individual who is suffering or who only thinks he is suffering, (which is often quite as sad a condition,) from his own misdeeds, and is deprived by the nature of these misdeeds from the sympathy and attention he would otherwise have, should be put in possession of a sufficiency of facts, to enable him to judge whether his fears are groundless, or whether it be not wiser to lay aside all reticence, and seek by prompt means a recovery.

Such have been our aims in composing the foregoing chapters. Whether or not we have succeeded in expressing ourselves regarding them lucidly, instructively, and satisfactorily, the reader who has accompanied us thus far, is better able to judge than ourselves.