154 Sylvius and his Pupils. [lect. 



he published some remarkable works on the structure of the 

 generative organs, and described the follicles in the ovary 

 which have ever since been known by his name. It was 

 however while a student at Leyden under Sylvius, in 1664, as 

 yet a youth of 23, that he made an investigation on pancreatic 

 juice, published under the title of Disputatio medica de natura 

 et usu sued pancreatici. 



In this tract after relating several unsuccessful attempts by 

 various methods at obtaining the juice he tells us how he hit 

 upon the right one. He made use of the quill of a wild duck, 

 which he says may be got longer and thinner than the quill of 

 any other bird. Into the far, narrower end of this he inserted 

 a plug of soft wood, attached to which, and carried through the 

 quill, was a long thread, by which the plug could be withdrawn. 

 Having performed tracheotomy on a dog (and he recommends 

 that the animal should be fasting) he opened the abdomen, liga- 

 tured the duodenum below the pylorus, and below the entrance of 

 the bile and pancreatic ducts, laid open the duodenum, sponged 

 the interior carefully, and then introduced the quill into the 

 mouth of the duct. The near, broader end of the quill was by 

 means of rolls of paper smeared with paste, firmly fitted into 

 the neck of a small flask, in the body of which was an orifice 

 made on purpose to allow air to escape, and through which the 

 thread attached to the plug of the quill was drawn. By the 

 help of rings round the neck of the flask it and the quill were 

 securely fastened in their place, and the wound in the abdomen, 

 from which the flask hung down, carefully sewn up. By means 

 of the thread the plug in the quill was then withdrawn and in 

 a short time the juice was observed to drop into the flask. In 

 this way De Graaf succeeded in obtaining from two drachms to 

 half an ounce, and in one case, that of a large dog, a whole ounce 

 of juice, in some seven or eight hours. 



This first cannalisation of the pancreatic duct seems to have 

 been adopted as a temporary measure only; there is no state- 

 ment of the animal having been kept alive for any length of 

 time. By the same method De Graaf also obtained saliva from 

 the parotid duct, and bile from the bile duct. He collected 

 parotid saliva and pancreatic juice from the same animal at the 



