It is an interesting inquiry to what extent the nature character, and frequency of disease in the human race are influenced by sex. The power of sex over disease exists to no inconsiderable degree. It is partly due to the difference in the physiological and partly to the diversity in the social life of man and woman. The extent and practical bearing of this influence upon health and longevity deserve more attention at our hands than they have received in an incidental manner elsewhere in this volume.

First, we shall inquire into