This biography is a sensitive and warmly personal account of the life of Paul Ehrlich, the discoverer of salvarsan (606). The author was Ehrlich's personal secretary from 1902 until his death in 1915 so that she is eminently qualified to record her firsthand observations of Ehrlich's daily work in his laboratory and at home. Where previously the man's scientific accomplishments have been recognized, his mental and spiritual greatness, his perpetual humility and his innate sympathy and kindliness toward his fellow man are now observed. The introduction by Sir Henry Dale confirms the subsequent story.
This is the story of Ehrlich's whole life, though it emphasizes the period during which the author worked for him. We learn of his early fascination with chemistry, his essential work in serum therapy, his development of "the side-chain theory," his growing preoccupation with chemotherapy and his discovery of salvarsan, which to him was only a