396 



H. T. Brown and J. Heron. 



[May 13, 



90 cub. centims. of a liquid containing 3*5 grms. of starch-products, 

 already reduced to the above point, were digested at 45° C. for twelve 

 hours, with the further addition of 10 cub. centims. of fresh pancreatic 

 extract. 



At the end of that time, the liquid having remained perfectly free 

 from organic life, the starch-products yielded on analysis the following 

 corrected numbers : — 



Mi3-86 128°*7 



corresponding very closely with the composition 



Maltose 55'5 



Dextrose . . 327 



Dextrin ...... 11-8 



100-0 



The united evidence afforded by many such experiments as the above 

 proves conclusively that the prolonged action of a pancreatic infusion 

 yields results differing materially from those obtained under similar 

 conditions with malt-extract. With malt-extract the hydrolytic effect 

 upon the starch-products, after No. 8 equation is reached, is confined 

 entirely to the conversion of the achroodextrin into maltose, tbe latter 

 body being the final product of the reaction. On the other hand, an 

 aqueous infusion of pancreas, whilst converting achroodextrin into 

 maltose, sensibly hydrolyses the maltose to dextrose. 



In order to put this important point of difference between the 

 action of malt and pancreatic extract beyond all doubt, a solution of 

 pure maltose was digested with an infusion of pancreas, in just the 

 same manner as maltose had, on many previous occasions, been treated 

 with malt- extract. 



100 cub. centims. of a solution cf maltose, containing 5 - 813 grms. 

 of substance, were mixed with 20 cub. centims. of a clear aqueous 

 infusion of pancreas, the infusion being added in successive portions of 

 5 cub. centims. each. Temperature of digestion 45° C. 



In four hours the optical activity of the 'solution had fallen from 

 Mj3-86' 150 o, 0, to [«] 3 . 8 65 148°'7; and after sixteen hours to [a] 3 . 86 , 

 135 0, 1 ; the value of k at the end of this time having risen from 61 to 

 67'3. The composition deduced from these latter numbers is 



Maltose 83'8 



Dextrose 16 - 2 



100-0 



This experiment, repeated many times, always gave the same re- 

 sults, thus proving that the amylolytic agent of the pancreas is capable, 

 as stated by Musculus and De Mering, of slowly converting maltose 



