332 DIGESTION. 



ed the same method of experimentation. The operative pro- 

 cedure consisted simply in making an incision into the ab- 

 dominal cavity, tying the intestine near the pylorus and a 

 little distance below the opening of the pancreatic duct, 

 opening the canal, and introducing a duck's quill into the 

 orifice of the pancreatic duct. By arranging a little vial in 

 such a position that fluid would drop into it from the quill, 

 De Graaf collected in this way from a dog, two drachms, 

 and even half an ounce of fluid in seven or eight hours. The 

 fluid thus obtained was sometimes acid, very often acid and 

 salt, and sometimes nearly insipid. Though, as has been so 

 conclusively shown by Bernard, the experiment of De Graaf 

 was nearly correct in principle, the fluid which he called 

 pancreatic juice lacked the constant and necessary property 

 of the normal secretion, namely, alkalinity. 1 



It is not necessary to detail the observations of all those 

 who, since De Graaf, have obtained fluid purporting to be pan- 

 creatic juice. Most of the early observations on this subject 

 were made with a view of proving either that the secretion 

 of the pancreas was or was not identical with the saliva, 

 and have no immediate bearing on our knowledge of the 

 true function of this organ. Magendie repeated the experi- 

 ment of De Graaf, but did not succeed in obtaining any 

 fluid. He operated by simply exposing the orifice of the 

 pancreatic duct and collecting with a pipette a few drops 

 of liquid as it flowed. He obtained thus only a small quan- 



1 KEGNERUS DE GRAAF, Tradatus Anatomico-Medicus de Sued Pancreatici 

 Natura et Usu. Ludg. Batavorum, Ex Officina Hackiana, 1671. In this curious 

 and interesting treatise, which is quite elaborate, the anatomical characters of 

 the pancreas are minutely described, the opinions of various authors concerning 

 its uses are discussed, experiments to obtain the pancreatic juice are detailed 

 with great care, and the properties of the fluid in health and disease are fully 

 considered. The whole is illustrated with a number of excellent engravings. 

 The process for obtaining the pancreatic juice so closely resembles that em- 

 ployed at the present day, that it is surprising that the normal fluid was not pro- 

 cured. Though De Graaf indicated very nearly the proper way to obtain pan- 

 creatic juice from a living animal, he developed little or nothing concerning ita 

 properties and functions. 



