vi] Sylvius and his Pupils. 155 



same time, and observed that the two juices differed in their 

 characters. It is interesting to note that this experiment 

 on the pancreas was never so far as is known repeated by 

 anyone until Claude Bernard in modern times took it up 

 again. 



De Graaf s record of the examination of the qualities or 

 characters of the juice is very meagre. There is no account of 

 any distinct chemical examination, he chiefly tested it by the 

 sense of taste. And he states that thus tested its qualities 

 were found to vary ; it was sometimes insipid, at other times 

 acid or rough, often salt, but most frequently acid-salt. 



He records that he had an opportunity once of examining 

 the pancreatic juice of a sailor who had died quite suddenly, 

 and that he found the human juice identical in its properties 

 with that of the dog. 



De Graaf then goes on to discuss the uses of this pancreatic 

 juice in digestion, and what he says may be taken as part of 

 the general teaching of Sylvius concerning digestion. 



Van Helmpnt, knowing nothing of either salivary or pan- 

 creatic ducts, held, as we have seen, that digestion consists 

 wholly in the two actions of the acid ferment of the stomach and 

 of the ferment of the bile. Sylvius on the contrary (naturally 

 perhaps inclined to give too much weight to a new discovery) 

 was led to attach the greatest possible importance to saliva; 

 he regarded it as the type of fermentative juices, of what he 

 calls a mild character, and attributed much of the changes 

 taking place in the stomach to the saliva swallowed with the 

 food rather than to the ferment provided by the stomach itself. 

 He appears to have considered that the mucus (pituita as it 

 was called) clinging to the interior of the intestine was in 

 reality the remains of the swallowed saliva ; and he went so far 

 as to hint that the change which the blood undergoes in the 

 lungs may be due to a mingling of the venous blood of the 

 pulmonary artery with some fluid secreted by the trachea and 

 bronchi, or with the saliva which somehow or other found its 

 way to the lungs. 



It was saliva then, in Sylvius's opinion, which was the chief 

 agent in bringing about the first stage of the fermentation 



