De Kruif writes the story of the male sex hormone with his usual ability to dramatize scientific observations.
Dr. H. N. Bundesen, health commissioner of Chicago, was responsible for De Kruif's personal sampling of the effects of the hormone. Dr. Bundesen also gave him new ideas about its possibilities as a "life-builder," in contradistinction to the ideas he had previously held about the irreversibility of old age, as stressed by his teacher of pathology, Dr. A. S. Warthin, of the University of Michigan.
De Kruif outlines the history of the hormone, pointing out that Brown-Séquard put it into the scientific "doghouse" from 1889 until 1926, when Koch and his associates began a new epoch of chemical investigation. By 1936, Butenandt, Laqueue and Ruzicka had performed their famous experiments, and the material first became available in quantity. Clinical observations showed its amazing effect on the sexual and somatic development of eunuchoid