A school of a more rational kind followed directly upon the work of Paracelsus, in which the first man of any importance was Van Helmont. The Paracelsian Archeus was the presiding spirit in living creatures, and worked through special local ferments, by which the functions of the organs are controlled. Disease of any part represents a strike on the part of the local Archeus, who refuses to work. Though full of fanciful ideas, Van Helmont had the experimental spirit and was the first chemist to discover the diversity of gases. Like his teacher, he was in revolt against the faculty, and he has bitter things to say of physicians. He got into trouble with the Church about the magnetic cure of wounds, as no fewer than twenty-seven propositions incompatible with the Catholic faith were found in his pamphlet (Ferguson). The Philosophus per ignem, Toparcha in Merode, Royenborch, as he is styled in certain of his writings, is not an easy man to tackle. I show the title-page of the "Ortus Medicinae," the collection of his works by his son. As with the pages of Paracelsus, there are many gems to be dug out. The counterblast against bleeding was a useful protest, and to deny in toto its utility in fever required courage--a quality never lacking in the Father of Modern Chemistry, as he has been called. A man of a very different type, a learned academic, a professor of European renown, was Daniel Sennert of Wittenberg, the first to introduce the systematic teaching of chemistry into the curriculum, and who tried to harmonize the Galenists and Paracelsians. Franciscus Sylvius, a disciple of Van Helmont, established the first chemical laboratory in Europe at Leyden, and to him is due the introduction of modern clinical teaching. In 1664 he writes: "I have led my pupils by the hand to medical practice, using a method unknown at Leyden, or perhaps elsewhere, i.e., taking them daily to visit the sick at the public hospital. There I have put the symptoms of disease before their eyes; have let them hear the complaints of the patients, and have asked them their opinions as to the causes and rational treatment of each case, and the reasons for those opinions. Then I have given my own judgment on every point. Together with me they have seen the happy results of treatment when God has granted to our cares a restoration of health; or they have assisted in examining the body when the patient has paid the inevitable tribute to death."(39) (39) Withington: Medical History from the Earliest Times, London, 1894, pp. 312-313.