394 



H. T. Brown and J. Heron. 



[May 13, 



isolated a soluble arnylolytic ferment from the pancreas, the former 

 observer by acidifying the aqneons infusion with phosphoric acid and 

 precipitating with lime ; the latter by the glycerine method first 

 described by "Wittich. 



Hiifner found that the isolated body, which was still doubtless 

 impure, contained 14" 95 per cent, of nitrogen, but a less quantity of 

 carbon and a greater quantity of oxygen than an ordinary albuminoid. 



Until recently it has always been taken for granted that the fermen- 

 table sugar produced by the action of pancreas upon starch-paste is 

 dextrose. Nasse, however, in 1878 (" Pfiiiger's Archiv f. Physio- 

 logic," 14, 473), attempted to show that the fermentable and cupric- 

 oxide reducing body, obtained by the action of saliva upon starch, is a 

 specific sugar which he calls ptyalose, and that the action of pancreatic 

 juice appears to result in the production of the same body. rTasse did 

 not isolate this hypothetical sugar, nor even approximately determine 

 its specific rotatory power, but relied mainly upon its non-reduction of 

 Barfoed's solution, and its doubling in reducing power on boiling with 

 dilute acid, as evidence of its non-identity with dextrose. 



In the early part of last year Musculus and De Mering published an 

 important memoir ("Bull. Soc. Chim.," 31, 105), upon the action of 

 diastase, saliva, and pancreatic secretion upon starch and glycogen. 



They concluded from their experiments that the fermentable sugar 

 produced in all these reactions is a mixture of maltose and dextrose. 

 We have shown in a recent communication to the Chemical Society 

 (•< Journ. Chem. Soc," 1879, 1, 648; " Liebig's Ann.," 199, 245), that 

 dextrose can certainly not be included, amongst the products of the 

 action of malt-diastase upon starch. The. experiments we are about to 

 describe will however afford ample proof of the correctness of that 

 portion of the above statement of Musculus and De Mering referring to 

 the action of pancreatic extract. 



Our experiments were made either with the aqueous infusion of the 

 gland, or with the actual tissue itself in a finely divided state. 



The first method is by far the most convenient, and is the one which 

 we generally adopted when studying the action of the pancreas, but it 

 will be seen that certain tissues can produce under some circumstances 

 hydrolytic effects which their aqueous infusions are incapable of exer- 

 cising. 



With a clear aqueous infusion of the gland the course of experiment 

 did not differ materially from that which we employed when investi- 

 gating the action of malt-diastase upon starch (loc. cit.). As a rule 

 the infusion had no power of reducing cupric-oxide, hence it was not 

 necessary to apply any correction to the quantity of cupric-oxide re- 

 duced by the transformation products. 



In cases where the transformation was effected by the actual tissue 

 itself, this was previously dried very rapidly in a current of air at 



