ALBUMENOID SUBSTANCES. 87 



the latter can be extracted by water, and subsequently precipitated by 

 alcohol from its watery solution. It is wanting in the pancreas of 

 newly-born infants. 



The second pancreatic ferment is known as "trypsine," from its 

 softening effect on coagulated albuminous matters. It acts upon them 

 somewhat like the gastric ferment, transforming them into peptone. 

 The pancreatic juice, as well as the extract of the pancreatic tissue, cer- 

 tainly contains a substance capable of digesting and dissolving coagu- 

 lated albumen or fibrine ; but this action is effected with readiness only 

 in an alkaline or neutral fluid, and is soon followed by putrescence. In 

 an acidulated solution it goes on with difficulty or not at all, and accord- 

 ing to Hoppe-Seyler is distinctly interfered with by the presence of 

 hydrochloric acid in the proportion of one part per thousand. It is 

 doubtful how far it takes place during digestion in the fluids of the small 

 intestine, which have normally an acid reaction. Pancreatine and tryp- 

 sine are accordingly two distinct substances with different properties, 

 the former having an action upon starch, the latter upon albuminous 

 matters. They are also, according to Langendorff,* produced in the 

 embryo at different periods of development ; trypsine showing itself at 

 the beginning of the fifth month, while pancreatine only appears after 

 birth. 



The third ferment in the pancreatic juice is one which causes the 

 acidification of neutral fats. This change may be produced with either 

 pancreatic juice, infusions of the gland, or fresh moist pieces of the 

 gland tissue, placed in contact, at 38 C., with liquid neutral fat ; their 

 normal alkalescence giving place, after a time, to an acidity due to the 

 liberation of fatty acid. So long as any surplus alkali remains, the 

 decomposed fat is saponified ; but the proportion which undergoes this 

 additional modification seems to be normally a small one. The pan- 

 creatic ferment which causes acidification of the fats has not been ob- 

 tained in a separate form. 



4. Fibrine-ferment. 



This is the substance which induces the coagulation of fibrinogen 

 and the production of fibrine in freshly drawn blood. It acts in such 

 minute quantity that it? physical and chemical characters have not 

 been accurately determined, and even its source is not fully known. But 

 in some way or other it appears in the blood soon after its discharge 

 from a wounded vessel, or even when its circulation has been arrested 

 by a ligature. It seems to be exuded, perhaps from the interstitial 

 fluids, wherever the walls of the blood-vessels are divided, bruised, 

 degenerated, or inflamed ; for at these situations the blood always 

 coagulates. It is obtained, according to the method of Schmidt, f from 

 blood-serum by coagulating it with 15 or 20 times its volume of strong 

 alcohol, and allowing the mixture to remain for two weeks, to secure 



* Archiv fiir Anatomie und Physiologic. Leipzig, 1879, p. 95. 



t Archiv fiir die gesammte Physiologic. Bonn, 1872, Band VI., p. 413. 



