204 PREPARATION OF SOLUTIONS OF PANCREATIC ENZYMES. [BOOK II. 



The diasta- 

 tic enzyme is 

 not only con- 

 tained in the 

 pancreatic 

 juice, but like- 

 wise in the 

 tissue of the 

 pancreas. 



An infusion of the pancreas acts upon starch 

 exactly in the same manner though not so energeti- 

 cally as the pancreatic juice, and we may therefore 

 employ in our experiments on the diastatic enzyme of 

 the pancreas such an infusion, instead of pancreatic 

 juice. 



Preparation of active Solutions containing the Enzymes 

 of the Pancreas. 



If is exceedingly convenient to have at our disposal permanent 

 solutions of the enzymes of the pancreas. The fat-splitting ferment 

 cannot, however, be indefinitely kept and special precautions must be 

 observed in order to extract it. See page 210. 



The pancre- 



J. < t 



All the pancreatic enzymes are extracted by gly- 



v,^iin from the gland, and SUch <? rrl\7r>nrin enlntirm 



may be preserved conveniently. 



Solubility of Roberts was the first to point out that they are like- 

 the enzymes in wise soluble in a saturated aqueous solution of chloro- 

 chioroform f ornij an( j t j ie S0 i ut i n keeps very well (Roberts 1 ). The 

 presence of chloroform interferes, however, with the 

 operation of testing for sugar by Fehlmg's solution. Salkowski 2 

 many years after Roberts recommended the use of chloroform as 

 a solvent of enzymes. 



cerin. 



Roberts 3 has found that for experimental purposes 

 the enzymes in a good and lasting extract of the pancreas may be 

 a solution con- ma( J e by extracting the organ with a solution which 



A. c -\ c r , c 



contains three or four per cent, of a mixture of two 



parts of boracic acid and one part of borax.' 



When the fresh pancreatic tissue is comminuted 

 and placed in a saturated solution of common salt, the 

 pancreatic enzymes are dissolved and powerfully active 

 solutions of these (the fat-decomposing ferment alone 

 exce P ted .) are obtained. This method of extracting the 

 pancreatic enzymes has been strongly recommended by 

 Harris and Gow 4 . 



Solubility of 



taming boracic 

 acid and borax 



Preparation 

 of a brine ex- 

 tract of the 

 pancreatic 



(Ro- 



1 Roberts, 'On the Digestive Ferments,' &c. The Lumleian Lectures for 1880. 

 London, 1880, p. 26. 



2 Salkowski, ' Ueber das eiweisslosende Ferment der Faulnissbakterien.' Zeitschrift 

 fur Biologic, Vol. xxv. (1889), p. 92. 



3 Eoberts, op. cit. p. 19. 



4 Harris and Gow, 'Ferment Actions of the Pancreas in different Animals.' By 

 Vincent D. Harris, M.D., F.E.C.P. and William J. Gow, M.D., M.E.C.P., Journal of 

 Physiology (Oct. 1892), Vol. 13, pp. 469492. 



