REGNIER DE GRAAF 



43 



of order by Regnier de Graaf, pupil of Francois de 

 Bois (Sylvius). De Bois had guessed that the 

 pancreas must be considered not according to its 

 position in the body, but according to its structure : 

 that it was analogous to the salivary glands. He 

 urged his pupil to make experiments on it : and de 

 Graaf says : — 



" I put my hand to the work : and though many 

 times I despaired of success, yet at last, by the 

 blessing of God on my work and prayers, in the 

 year 1660 I discovered a way of collecting the 

 pancreatic juice." 



And, by further experiment, he refuted Bartholin's 

 theory that the pancreas was dependent on the 

 spleen. 



Sylvius had supposed that the pancreatic juice 

 was slightly acid, and de Graaf failed to note this 

 mistake ; but it was corrected by Bohn's experi- 

 ments in 1 7 10. 



Nearly two hundred years come between Regnier 

 de Graaf and Claude Bernard : it is no wonder that 

 Sir Michael Foster says that de Graafs work was 

 "very imperfect and fruitless." So late as 1840, 

 there was yet no clear understanding of the action 

 of the pancreas. Physiology could not advance 

 without organic chemistry ; de Graaf could no more 

 discover the amylolytic action of the pancreatic juice 

 than Galvini could invent wireless telegraphy. The 

 physiologists had to wait till chemistry was ready 

 to help them : — 



" Of course, while physical and chemical laws 



