DISCOVERY OF PROTEINE. 105 



potash, and the solution is exposed for some time 

 to a high temperature, these substances are decom- 

 posed. The addition of acetic acid to the solution 

 causes, in all three, the separation of a gelatinous 

 translucent precipitate, which has exactly the same 

 characters and composition, from whichever of the 

 three substances above mentioned it has been ob- 

 tained. 



Mulder, to whom we owe the discovery of this 

 compound, found, by exact and careful analysis, that 

 it contains the same organic elements, and exactly 

 in the same proportion, as the animal matters from 

 which it is prepared ; insomuch, that if we deduct 

 from the analysis of albumen, fibrine, and caseine, 

 the ashes they yield, when incinerated, as well as 

 the sulphur and phosphorus they contain, and then 

 calculate the remainder for 100 parts, we obtain 

 the same result as in the analysis of the precipitate 

 above described, prepared by potash, which is free 

 from inorganic matter. (22) 



Viewed in this light, the chief constituents of the 

 blood and the caseine of milk may be regarded as 

 compounds of phosphates and other salts, and of 

 sulphur and phosphorus, with a compound of carbon, 

 nitrogen, hydrogen, and oxygen, in which the rela- 

 tive proportion of these elements is invariable ; and 

 this compound may be considered as the com- 

 mencement and starting-point of all other animal 

 tissues, because these are all produced from the 

 blood. 



