404 LIQUID PARTS OF ANIMALS. 



It was afterwards collected and examined by Sclmyl, Wepfer, 

 Pechlin, Brunner,- and J. Bohn ; the first of whom confirmed, 

 while the others combated the opinions of De Graaf. But, from 

 the infant state of chemistry at the time when they lived, their 

 examinations could scarcely lead to any satisfactory result. 



After some progress had been made in the investigation of 

 animal fluids, a few observations on the pancreatic juice were 

 made by Mayer. Magendie also attempted to collect it, though 

 he succeeded in obtaining only a few drops. He found it yel- 

 lowish, saline, alkaline, and coagulable by heat.* 



The most celebrated physiologists of the last century, Hoff- 

 mann, Stahl, Boerhaave, Haller, &c. concur in opinion, that the 

 pancreatic juice is of a similar nature with saliva. And this opi- 

 nion, founded on the similar appearance of the pancreas and pa- 

 rotids, was generally adopted. The experiments ofTiedemann 

 and L. Gmelin, detailed in their work on digestion, have at last 

 given us some facts, which will enable us to decide this long dis- 

 puted point. 



They collected the pancreatic juice of the dog, the sheep, and 

 the horse, by the same method which had been previously em- 

 ployed by De Graaf, and which succeeded with them perfectly ; 

 though it had failed with Magendie. 



It appears from their experiments, that the quantity of pan- 

 creatic juice secreted is not large. They found it always acid 

 when the animal was in full vigour ; but when its health and 

 strength were enfeebled by the painful situation in which it was 

 placed, the pancreatic juice became alkaline. In four hours 

 they collected from the pancreas of a large dog 154 grains of 

 pancreatic juice. After the experiment was finished, the glass 

 tube through which the juice had flowed was withdrawn, the ex- 

 cretory duct was tied up, the viscera replaced in the abdomen, 

 and the external wound closed by sutors. The animal gradual- 

 ly recovered, and continued in perfect health for eleven weeks. 

 He was killed, and the state of the excretory ducts of the pancre- 

 as examined. There were two pancreatic ducts in that dog. 

 The larger had been tied up, but the smaller, which entered the 

 duodenum along with the ductus communis choledochus, supplied 

 its place. 



The pancreatic juice thus collected was opal coloured, and was 



* Physiologic, ii. 367. 



