PEPSIN. 1033 



is left undissolved, like the acetate of pepsin. It possesses 

 properties analagous to those of the acetate, and its solution in 

 water dissolves coagulated albumen very rapidly. The alcoholic 

 liquor above possesses no solvent power ; when evaporated to 

 dryness it leaves a residue which resembles an extract of meat. 

 In regard to the solvent power of pepsin for coagulated 

 albumen, it was observed by M. Wasmann that a liquid which 

 contains 1.7 thousand parts of acetate of pepsin and 6 drops of 

 hydrochloric acid per ounce, possesses a very sensible solvent 

 power, so that it will dissolve a thin slice of coagulated albumen 

 in the course of 6 or 8 hours 3 digestion. With 12 drops of 

 hydrochloric acid per ounce the white of egg is dissolved in 2 

 hours. A. liquid which contains \ grain of acetate of pepsin 

 and to which hydrochloric acid and white of egg are alternately 

 added, so long as the latter dissolves, is capable of dissolving 

 210 grains of coagulated white of egg at a temperature between 

 95 and 104 It would appear, from such experiments, that the 

 hydrochloric acid is the true solvent, and that the action of the 

 pepsin is limited to that of disposing the white of egg to dissolve 

 in hydrochloric acid. The acid when alone dissolves white of 

 egg, by ebullition, as it does under the influence of pepsin ; from 

 which it follows that pepsin replaces the effect of a high tem- 

 perature which is not possible in the stomach. The same acid 

 with pepsin dissolved blood, fibrin, meat and cheese, while the 

 isolated acid dissolved only an insignificant quantity, at the same 

 temperature ; but when raised to the boiling point it dissolved 

 nearly as much, and the part dissolved appeared to be of the 

 same nature. The epidermis, horn, the elastic tissue (such as the 

 fibrous membrane of the arteries) do not dissolve in a dilute 

 acid containing pepsin. 



M. Wasmann has remarked that the pepsin of the stomach 

 of the pig is entirely destitute of the power to coagulate milk ? 

 although the pepsin of the stomach of the calf possesses it in 

 a very high degree, from which he is led to suppose that the 

 power of the latter depends upon a particular modification of 

 pepsin, or perhaps upon another substance accompanying it, 

 which ceases to be formed when the young animal ceases to be 

 nourished by the milk of its mother. 



IIEMATOSIN. 



The blood so long as it flows in the veins consists of a clear 



