178 DIGESTION. 



and valuable observations on this subject are those of Kiihne, 1 who ex- 

 perimented both with the pancreatic juice of the dog, and also with infu- 

 sions of the glandular tissue. He found that the fresh viscid secretion 

 could, in from half an hour to three hours, effect the solution of coagulated 

 fibrine and albumen, without any modification of its alkaline reaction, 

 and without giving rise to signs of putrefaction ; the albuminous mat- 

 ters, thus dissolved, being changed into a substance not coagulable by 

 boiling and readily diffusible through parchment paper. The product of 

 this action accordingly resembles that obtained from a similar digestion 

 with the pepsine of gastric j nice. 



In his experiments with the glandular tissue, Kiiline placed the finely 

 divided gland in warm water together with a weighed quantity of the 

 substance to be experimented on ; allowing the infusion of the pancreas 

 and the digestion of the albuminous matter to proceed simultaneously. 

 He found that when employing for this purpose a dog's pancreas of from 

 50 to 60 grammes weight, 400 grammes of boiled and pressed fibrine, 

 after remaining in the infusion at 40 to 45 (104 to 113 F.) for from 

 three to six hours, were reduced to an insignificant residue, the reaction 

 of the mass continuing throughout faintly alkaline. 



The details of this process, however, are different in some respects 

 from those of digestion in gastric juice. If bits of coagulated fibrine 

 be placed in gastric juice, or an acidulated solution of pepsine, they first 

 swell up and become transparent under the influence of the free acid; 

 and this action is preliminary to their subsequent solution and transfor- 

 mation into albuminose. But in an infusion of the pancreas, according 

 to Kiihne, the pieces of fibrine do not become at all swollen or altered 

 in transparency, even when considerably softened and near the point 

 of solution. They are, however, essentially modified in their physical 

 and chemical properties. Boiled fibrine, by itself, is but slowly affected 

 by dilute acids or alkalies, and is nearly or quite insoluble in a ten per 

 cent, solution of hydrochloric acid; but after remaining for a time in 

 an infusion of the pancreas, a part of it is found to be almost instantly 

 soluble in a solution of hydrochloric acid of one part per thousand. 



It is evident, accordingly, that the organic matter of the pancreatic 

 juice may exert a transforming action on the albuminous matters, some- 

 what analogous to that of the pepsine of gastric juice. How far this 

 action takes place in the natural process of digestion has not been 

 demonstrated by direct observation, but it is possible that the two 

 secretions may be in some degree complementary to each other. In the 

 gastric juice, we have an abundant fluid with an acid reaction, and with 

 a small proportion of organic substance ; in the pancreatic juice a com- 

 paratively scanty secretion, but with a much larger proportion of organic 

 matter, capable of exerting a transforming power on the albuminous 

 ingredients of the food. While the gastric juice acts alone in the 

 stomach, softening and disintegrating the food, and actually dissolving 



1 Archiv fur Pathologische Anatomie und Physiologie, 1867, xxxix. p. 130. 



