vi] Sylvius and his Pupils. 147 



latter half of the nineteenth century has produced such useful 

 results. But he cared more for practical guidance than for 

 theoretical conclusions. He regarded his balance as a means 

 of helping a man ' to live according to rule.' He proposed that 

 each meal should be taken sitting in his chair with the steel- 

 yard so adjusted that by the descent of the chair the diner 

 should be warned that the predetermined weight of food had 

 been swallowed. He was obviously a singularly original man ; 

 we learn for instance that he invented a thermometer for 

 measuring the heat of the animal body, and an instrument for 

 measuring the movements of the arteries. 



We must however now return to the successors of van 

 Helmont. 



In 1614, the year before van Helmont wrote his first book 

 and fourteen years before Malpighi's birth, there was born at 

 Hanover of a good family one Francois De le Boe or Dubois, 

 better known perhaps by his Latin name as Franciscus Sylvius. 

 He is the second prominent man of that name in the history of 

 physiology, the first being Jacobus Sylvius of Paris, in the 

 sixteenth century, the teacher of Vesalius. Though a man 

 of a wholly different type of intellect from van Helmont, 

 Sylvius appears in the history of physiological thought as 

 his legitimate descendant. 



After studying at Sedan, at Basel, where in 1637 he took 

 his degree, and elsewhere, and after a stay of some years at 

 Amsterdam he became in 1658 Professor of Medicine at 

 Leyden, and there for many years exerted a most powerful 

 influence until his death in 1672. 



In order to understand the importance and bearing of his 

 physiological and medical teaching, the nature of which may be 

 learnt from his many medical and physiological writings, it 

 must be borne in mind that he was not only a physician and a 

 physiologist, but also distinctly and clearly what we should now 

 call a chemist. He published many purely chemical works. He 

 persuaded the Curators of the University of Leyden to build for 

 him a ' Laboratorium, as they call it ' ; this seems to have been 

 the first University Chemical Laboratory. 



Like Glauber, an older man, born in 1604 and dying in 



10—2 



