This seems to be a period prolific of new diseases. In the thirteenth, fourteenth and fifteenth centuries we hear most of leprosy, and of the visitation of the plague in Europe. Whooping-cough and scurvy were never described by any writer anterior to the fifteenth century. Syphilis was first recognized in Italy in the fifteenth century, from which country it spread rapidly over the whole of Europe. In the sixteenth century the study of human anatomy may be said to have been fairly established by the zeal and labors of Vesalius, and in this and the succeeding centuries we meet with the names of many physicians whose anatomical and physiological investigations tended either directly or indirectly to advance the science of medicine. This was the epoch of Eustachius, Fallopius, Asellius, Harvey, Rudbeck, Bartholini, Malpighi, Glisson, Sylvius, Willis, Bellini, etc., names preserved in anatomy. Chemistry was now being separated from alchemy, and advancing to a science, and a combination formed between its principles and those of physiology, which gave rise to a new sect of chemical physicians, quite distinct from the sect represented two centuries before by Paracelsus. The chemical school was succeeded by the mathematical school, of which Borelli, Sauvages, Heill, Jurin, Mead and Freind were amongst the most celebrated. While at the same time the old Galenists were fast disappearing. To the rival sects of this period must be added the Vitalists, which originated with Von Helmont, and with some modifications was adopted by Stahl and Hoffman. The greatest physician of the seventeenth century was, however, Sydenham, who, though inclining to the chemical school, did not allow his speculative opinions regarding the nature of disease to interfere with a careful consideration of the indications for treatment, as derived from the symptoms, and from experience.