66 VIEWS OF THE IATKO-CHEMISTS ON DIGESTION. [BOOK II. 



F. De le Boe The idea that digestion was a process akin to fer- 

 Syivius. mentation was advocated by the celebrated F. De le Boe 



Sylvius (born 1614, died 1672), Professor of Medicine in the University 

 of Leyden, one of the most celebrated medical teachers of his age. 

 and the chief representative of the iatro-chemical school. Whilst v. 

 Helmont had used the term fermentation to designate any chemical 

 operation which appeared to him utterly inexplicable and essentially 

 associated with vitality, Sylvius 1 by referring to alcoholic and acetous 

 fermentations leads us to conclude, that these were types of the 

 processes which he believed to occur in the alimentary canal. There 

 is no evidence, however, of any original observations made by Sylvius 

 in reference to gastric digestion, and on this as on all other matters 

 he wrote so as to cause us to marvel that the crude dogmas and 

 ridiculous jargon of the iatro-chemical school should even for a, time 

 have held sway in the medical world. 



Descartes Absurd though they appear to us, many of the 



Willis. doctrines of the iatro-chemical . school received the 



support of such men as the great mathematician and philosopher 

 Rene Descartes (born 1596, died 1650) and our own anatomist 

 Thomas Willis (born 1621, died 1675). 



Descartes believed that an acid of extreme potency, compar- 

 able to nitric acid, is generated in the stomach, as a result of a 

 peculiar fermentation. Willis, who in spite of his thoroughly sound 

 anatomical training, was a credulous adherent of the iatro-chemical 

 school, also speculated upon the existence of an acid ferment in the 

 stomach. 



Grew. Although unconnected with the school to which 



reference has been made, the name of the observant 

 Nehemiah Grew (born 1628, died 1711) must be mentioned amongst 

 those who in the 17th century wrote concerning the nature of gastric 

 digestion. Unlike those whose works have been referred to, Grew 2 

 wrote very briefly, but his writings mainly consisted, as was his wont, 

 of the records of his own observations, though he could not resist the 

 tendency of his age to speculation. He noticed the existence of 

 glands in the mucous membrane of the stomach : 



* By the joynt assistance of the glandulous and the nervous membranes 

 the business of chylification seems to be performed. The mucous excre- 

 ment of the blood supplied by the former, as an animal corrosive preparing, 

 and the excrement of the nerves by the latter, as an animal ferment per- 

 fecting the work/ 



1 F. D. Sylvii Opera omnia. Editio nova. Trajecti ad Ehenum, 1663. Kefer to 

 'Disputatio Medica I. De Aliinentorum fermentatione in ventriculo ' (p. 11). 



2 Grew, The Comparative Anatomy of Stomach and Guts begun, being several lectures 

 read before the Royal Society in the year 1676. London, printed for the author, 1681. 

 See 'On the uses of the stomach of quadrupeds ' (p. 26). 



