Page:Greek Biology and Medicine.djvu/156

 GREEK BIOLOGY AND MEDICINE Belonging to Harvey's own generation, the extraordinary Fleming, van Helmont, forms a link between Paracelsus and the theorizing systems of the medico-chemical and medico- physical schools of the early seventeenth cen- tury. The chemical school (Sylvius of Leyden may be called the founder) starts from the con- ception of fermentation through the action, for example, of the saliva and gastric juices upon foods. Health consisted in the proper balance of acids and alkalies, and sickness in the excess of one or the other. The cure lay in the re- duction of the excessive element. On the other hand, the physicists, starting from the admitted circulation of the blood, sought a physical or mechanical interpretation of all bodily processes. Health lay in their unim- peded action. Since the physical as well as chemical knowl- edge of that time was utterly inadequate for the basis of sound medical practice, a reaction was to be expected. The advocates of these theories had drawn more than one conception from Greek medicine, to weave into their systems. Now the reaction inaugurated by the Englishman, Thomas Sydenham (1624- 1689), directed itself toward the conscious [134]