118 COMPOSITION OF FIBRINE. 



and hydrogen with the sulphur and phosphorus does 

 not exclude the addition of the elements of water, and 

 if we assume that fibrine and albumen, 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 probability, that the ultimate analysis 

 of these compounds will 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 

 unoxidized phosphorus in albumen and fibrine from the 

 formation of sulphuret of potassium when they are 

 acted on by potash, supposing the oxygen of the pot- 

 ash to have formed phosphoric acid with the phospho- 

 rus ; but caseine, which contains no phosphorus, yields 

 sulphuret of potassium, just like the other substances ; 

 and here its formation cannot be accounted 1 for, unless 

 we admit the previous production of sulphuretted hy- 

 drogen. In the mere boiling of flesh, for the purpose 

 of making soup, sulphuretted hydrogen, as Chevreul 

 has shown, is disengaged. 



Moreover, the proportion of sulphur, for the same 

 amount of phosphorus, is not the same in fibrine and 

 albumen, from which no other conclusion can be drawn, 

 but that the formation of sulphuret of potassium has no 

 relation to the presence of phosphorus. Sulphuret of 

 potassium is formed from caseine, which is not sup- 

 posed to contain any uncombined phosphorus ; and it 



