tous discoveries until the advent of anesthesia and asepsis in the middle of the nineteenth century. We may therefore leave surgery and turn to Harvey and events in physiology prior to 1800.
Harvey was of the Elizabethan period, a contemporary of Shakespeare, Milton, Dryden, Bacon, Descartes and Kepler. He studied at Cambridge and Padua and on his return to England, as Lumleian lecturer, gave most of his time to teaching and dissection. It was during the second year (1616) of such labors that he first propounded his theory of the circulation of the blood, but it was not until 1628 that his complete work on the subject was published. With the discussion as to the part played by his forerunners, by Servetus, Cæsalpinum and others in elucidating the mysteries of the circulation we are not now concerned. The honor of the establishment of the theory is Harvey's. More than this, it was the character of his exhaustive observations on a score of different animals (and on the heart of the chicken in ovo), his logical reasoning, and his convincing experiments that finally led to the correct solution and to the resurrection of a new method in medicine, that of experimental physiology. It may be remembered that Galen has been referred to as the first experimental physiologist; after fourteen hundred years he was followed by Harvey; then came Haller and Hunter, prophets of that modern experimental physiology which was in the nineteenth century to advance along all lines and to give to medicine a scientific foundation.
It is difficult to overestimate the significance of Harvey's discovery of the circulation of the blood. Sir Thomas Brown considered it greater than Columbus's discovery of America; Hunter ranked it with that of Columbus and that of Copernicus. Certainly it opened a new world in medicine. Progress, however, did not immediately follow Harvey's discovery, though four years after his death the capillary system, a link necessary to the completion of his doctrine of the circulation, was discovered by Malpighi. The period, was, however, one of detailed observation in anatomy, and despite the work of Malpighi and Borelli, experimental physiology languished until the time of Haller (1708-1777), who made additions to the knowledge of the mechanics of respiration, established the theory of irritability as a specific property of muscle and made important observations in embryology. How prophetic of the advances of the nineteenth century are the problems with which Haller and Hunter busied themselves. The study of the irritability of muscle suggests physiological instruments of precision, and embryology implies the compound microscope and the microtome, the familiar instruments of the latter nineteenth-century investigator in medicine. Hunter's problems—phlebitis, aneurism, syphilis, inflammation, the repair of wounds, the coagulation of the blood—remind one of many phases of present-day investigation. Prophetic also of the
