ALBUMEN, AND CASEINE. 123 



nation with oxygen, the amount of oxygen in fibrine 

 would be reduced from 22*715 22-00 per cent, to 

 22-5 21-8 per cent, in proteine. But the limits of 

 error in our analyses are, on an average, beyond 

 xVth per cent, in the hydrogen, and beyond T 4 oths 

 per cent, in the oxygen ; while in the supposed case 

 the difference in the hydrogen would not be greater 

 than Tsth per cent. 



Finally, if we reflect, that the elimination of oxy- 

 gen and hydrogen with the sulphur and phosphorus 

 does not exclude the addition of the elements of 

 water, and if we assume that fibrine and albu- 

 men, in passing into proteine, do combine with a 

 certain quantity of water, an occurrence which is 

 highly probable, we shall see that there is no proba- 

 bility that the ultimate analysis of these compounds 

 shall ever enable us to decide such questions, or to 

 fix the chemical view of the relation of proteine to 

 albumen, fibrine, or caseine, farther than has been 

 done above. 



Some have endeavoured to prove the existence of 

 unoxidised phosphorus in albumen and fibrine from 

 the formation of sulphuret of potassium when they 

 are acted on by potash, supposing the oxygen of the 

 potash to have formed phosphoric acid with the 

 phosphorus ; but caseine, \vhich contains no phos- 

 phorus, yields sulphuret of potassium, just like the 

 otherieubstances ; and here its formation cannot be 

 accounted for, unless we admit the previous pro- 

 duction of sulphuretted hydrogen. In the mere 



