PROPERTIES OF PANCREATIC FLUID AND BILE. 171 



mens of pancreatic juice, the last is only displayed with certainty by the 

 juice and extract of the rosy gland, obtained during digestion.' In addition 

 to its i-niH/xij'i/hiy power over fats, the pancreatic juice can exert a chemical 

 action, effecting the disintegration of the more easily decomposable fats into 

 glycerin and the fatty acids, and this, according to Briicke, materially facil- 

 itates the formation of a permanent emulsion. 2 The saccharifying influence 

 of the pancreatic juice upon starch was first observed by Valentin, and may 

 be proved by adding the healthy secretion obtained by a fistulous opening, 

 or even an infusion of the gland-substance, to either crude or boiled starch ; 

 for though the energy of the action is much greater in the latter case, yet 

 even in the former the starch-grains become rapidly altered in form, disin- 

 tegrate, and dissolve, grape-sugar being at the same time produced. 3 The 

 necessity which exists for the conversion of starch into sugar before it can be 

 absorbed, renders evident the advantage which attends the presence of a 

 gland possessing a similar transforming power to that of saliva, at some dis- 

 tance from the mouth, where it may act upon crude starch, now softened, 

 swollen, and otherwise affected by the combined heat and moisture of the 

 stomach, and which would otherwise escape being acted on. The amylolytic 

 power of the pancreatic fluid has been shown by Dr. M. Foster 4 not to de- 

 pend on the pancreatiu it contains ; and Cohuheim and Danilewsky believe 

 they have isolated the substance possessing this peculiar power, and have 

 satisfied themselves it is not a proteid. The action exerted is undoubtedly 

 that of a ferment, since an indefinite quantity of starch can be converted into 

 sugar by a definite quantity of the ferment. Its operation is not interfered 

 with by the presence of the gastric juice. The pancreatic juice is not, how- 

 ever, exclusively destined for this function, sharing it with the " succus en- 

 tericus," which has been shown by Frerichs and Hiibbeuet, and especially 

 in the interesting case recorded by Busch, to be also possessed of this con- 

 verting power. 



121. But secondly, it has been affirmed by M. Cl. Bernard, and strong 

 evidence has been adduced by him in support of his statement, that the 

 essential purpose of the Pancreatic fluid is to promote the absorption of fatty 

 matters, by reducing them to the state of an emulsion, which is capable of 

 finding its way into the lacteals. That this fluid possesses the emulsifying 

 power in a peculiar degree, may be considered as having been fully demon- 

 strated by his experiments; for on mixing it with oil, butter, or any variety 

 of fat, at a temperature sufficiently high to render the fatty substance liquid, 

 and then stirring the mixture for a few minutes, an emulsion is produced, 

 bearing a strong resemblance to chyle. This emulsion does not cease to 

 present its peculiar aspect, even when left standing for some time; whereas, 

 although bile, saliva, gastric juice, blood-serum, and other animal fluids, 

 have a certain emulsifying power, yet, after a short time, the oil-particles 

 run together again, almost as if they had been merely shaken up with water. 

 Further, it is asserted by Bernard, that in the Rabbit (in which the pan- 



1 Wundt, Physiologic, 1873, p. 217. Bernstein, Leipziger Arbeiten, 1870, p. 33, 

 states that he could obtain little or no secretion from healthy fasting dogs, but that 

 the pancreatic juice ( 105) always acted well in dissolving Fibrin. 



2 See Briicke, Physiologic, 1874, p. 329. 



3 In unhealthy conditions, it is not unlikely that the same changes may take place 

 as occur when pancreatic juice is allowed to remain long upon starch-paste at a mod- 

 erately high temperature; these changes being accompanied with the evolution of 

 hydrogen, nitrogen, and carbonic acids, indicating the occurrence of the lactic, 

 butyric, or even alcoholic fermentation. 



4 Humphry and Turner's Journal of Anat. and Physiol., vol. i, 1866, p. 108. 



5 Virchow's Archiv f. path. Anat. und Physiol., vol. xiv, p. 140. See also Can- 

 statt's Jahresbericht, 1862, p. 112. 



