vi] Sylvius and his Pupils. 161 



work of some coming after him who called themselves his 

 disciples. 



Sylvius had no such exact knowledge at his back. He was 

 groping his way in the dim twilight of a rising but not yet 

 risen science; in that dim light he confounded shadows with 

 things, and mistook the size of images looming in the mist of 

 the dawn. 



Moreover, he had neither the strength nor the width of 

 mind of Borelli. He was one of those who think that a 

 well -sounding phrase is of necessity a carrier of truth, and 

 he was also one of those who are prepared to explain every- 

 thing, and are satisfied themselves with every explanation 

 which they give. For almost every physiological problem he 

 had a chemical illustration ready at hand ; and he seems to 

 have had no manner of doubt that an adequate knowledge of 

 alkalis and acids would carry him triumphantly through all the 

 difficulties both of health and disease. While Borelli was in 

 the main a philosopher only, Sylvius was an active physician ; 

 as he considered health to be ordered and appropriate chemical 

 change, so he regarded disease to be excessive or deficient or 

 perverted chemical change, a change which he hoped to cure by 

 the skilful addition or withdrawal of acids and the like. And 

 though his followers abused chemical, as much as Borelli's 

 followers abused physical knowledge, none of them perhaps 

 ever exceeded their master in the unbounded confidence which 

 he had in the validity of his method. 



The importance of Sylvius in the history of physiology 

 attaches as we have seen rather to his zealous teaching of the 

 value of chemical knowledge as a means of solving vital pro- 

 blems, than to any special discoveries of his own. He was 

 happier when dealing, with digestion than with other pheno- 

 mena, though his success in this he owed largely to Stensen 

 and De Graaf. And one cannot but admit that in attaching 

 such great importance as he did to the pancreatic juice, wrong 

 as his interpretation of the nature of the action of that juice 

 might have been, he anticipated by some two centuries the 

 labours of Claude Bernard. But even that merit soon seemed 

 to be taken away from him. 



p. l. 11 



