My dear old teacher, Virchow, of whom they said when he died that four men died, for he was distinguished not only as a pathologist, {11} which was the great life-work for which he was known, but as an anthropologist, a historian of medicine and a sanitarian, was at seventy-five actively accomplishing the work of two or three men. He died at eighty-one, as the result of a trolley injury, or I could easily imagine him alive even yet. Von Ranke, the great historian of the popes, began a universal history at the age of ninety which was planned to be complete in twelve volumes, one volume a year to be issued. I believe that he lived to finish half a dozen of them. I have some dear friends among the medical profession in America who are in their eighties and nineties, and all of them were extremely busy men in their middle years and always lived intensely active lives. Stephen Smith and Thomas Addis Emmet, John W. Gouley, William Hanna Thompson, not long dead, and S. Weir Mitchell, who lived to be past eighty-five, are typical examples of extremely busy men, yet of extremely long lives. All of these men had the will power to keep themselves busily at work, and their exercise of that will power, far from wearing them out, actually seemed to enable them to tap reservoirs of energy that might have remained {12} latent in them. The very intensiveness of their will to do seemed to exert an extensive influence over their lives, and so they not only accomplished more but actually lived longer. Hard work, far from exhausting, has just the opposite effect. We often hear of hard work killing people, but as a physician I have carefully looked into a number of these cases and have never found one which satisfied me as representing exhaustion due to hard work. Insidious kidney disease, rheumatic heart disease, the infections of which pneumonia is a typical example, all these have been the causes of death and not hard work, and they may come to any of us. They are just as much accidents as any other of the mischances of life, for it is as dangerous to be run into by a microbe as by a trolley car. Using the will in life to do all the work possible only gives life and gives it more abundantly, and people may rust out, that is be hurt by rest, much sooner than they will wear out.