Modern preventive medicine may be said to date from the introduction of inoculation for smallpox in the early part of the eighteenth century. It is much more profitable to dwell on the history of the second step in this direction, a far greater one, due to the genius of one man, Edward Jenner, whose Life by Dr. Baron, though not a biographical masterpiece, is the source of much valuable information. The name of Stephen Jenner had been handed down from generation to generation in Gloucestershire, and the Rev. Stephen Jenner, father of Edward, was vicar of Berkeley when his famous son was born, on May 17, 1749. The father, however, died in 1754, and an elder son, another Stephen Jenner, Fellow of Magdalen College, Oxford, is credited with some attention to his education. But his school life was not prolonged, for about the thirteenth year of his age he commenced preparation for a medical career by entering upon apprenticeship to Mr. Daniel Ludlow, a medical practitioner at Sodbury near Bristol, with whom he remained six years. Young Edward, when a fine ruddy boy of eight, was, with many others, put under a preparatory process for inoculation for smallpox. This was indeed a formidable proceeding, lasting six weeks. He was first bled, to ascertain whether his blood was “fine;” was then purged repeatedly till the ruddy youth became emaciated and feeble; and all the while was kept on a low diet, and dosed with some drink which was supposed to sweeten the blood. This is appropriately termed a “barbarism of human veterinary practice,” but it was followed by exposure to contagion from others in a state of severe disease. By good luck the boy got off with a mild attack; but we may well ascribe to the lowering preparatory treatment he had undergone, that he never could as a child enjoy sleep, and was constantly haunted by imaginary noises. All his life long he was too acutely alive to these impressions and to any sudden jar.