114 THE PANCREATIC JUICE. 



In reference to the mineral ingredients (as determined by inci- 

 neration), Frerichs found 1'01-g- in the secretion from the ass; of 

 this amount, 0*12^ was insoluble, and consisted of carbonate and 

 phosphate of lime and magnesia., and 0'89f was soluble, consisting 

 of chloride of sodium and alkaline phosphates and sulphates. 



Nothing can be stated with any accuracy regarding the quanti- 

 tative relations of the secretion, since the injury caused by the 

 operation which is necessary for the purpose of observing the 

 secretion must very much derange the physiological relations. 

 The experiments of Frerichs merely show that it is only during 

 digestion that the pancreatic juice is secreted. In a state of 

 abstinence, Frerichs found the gland pale and anaemic, and the 

 duct of Wirsung empty. 



Frerichs collected 25 grammes from an ass in three-quarters of 

 an hour, but only 3 grammes from a hound in twenty- five minutes, 

 during the process of digestion; Bernard obtained 8 grammes 

 from a large dog in one hour, and 16 grammes hourly after inflam- 

 mation had been set up. Bernard found, as a general result, that in 

 the latter case there was always an increased flow of the pancreatic 

 juice, but that it ceased to be coagulable and viscid. 



Diseases of the pancreas are, as is well known, extremely rare ; 

 I once found, in the duct of Wirsung, a concretion which exhibited 

 all the characters of a protein-body, but differed from the better 

 known salivary concretions in yielding very little carbonate and 

 phosphate of lime, and indeed very little ash at all. 



The importance of the pancreatic juice in relation to digestion 

 was first recognized by Valentin ; it converts into sugar the 

 amylaceous matters which have not been metamorphosed by the 

 saliva, and have passed unchanged into the duodenum. Valentin 

 supported his opinion by the fact that the pancreas is much more 

 developed in herbivorous than in carnivorous animals, and con- 

 vinced himself that the expressed juice, or an infusion of the sliced 

 gland, possesses in a high degree the power of converting starch 

 into sugar. Bouchardat and Sandras* found that the juice dis- 

 charged from Wirsung's duct by fowls or geese possessed this 

 property, but lost it after being heated to 100. They further 

 ascertained that this property is peculiar to the nitrogenous or 

 albuminous substance which is precipitable by alcohol, and after- 

 wards soluble in water. More recently, this subject has been 

 investigated with the greatest scientific accuracy by Bernard and 

 Frerichs, to whose labours we have so often referred, as well as 

 * Compt. rend. T. 20, p. 1085. 



