358 Letter pom Professor Mulder. 



You will see that, when we subtract from the above protein an 

 equivalent of hyposulphurous acid, and from albumen an equivalent 

 of sulphuret of amid, the same body is left. 



I am able to adduce much more decisive instances of the reality 

 of the existence of the compound S N H^ (sulphuret of amid), in 

 these bodies. Cow-hoofs, for instance, gave (Phys. Chem., p. 664):-— 



This, therefore, is again the same body, and it is the true compo- 

 sition of desulphuretted protein. 



Cow-horns, like fibrin, yield without doubt an oxide of protein. 

 Thus, cow-horns {Phys. Chem.^ p. 568), gave : — 



Deducting the sulphur, as 



S, N H2 :— 



50-1 53-8 



6-3 6-8 



13-2 14-2 



23-5 25-2 



100- 93-1 100- 



And fibrin {Scheik, Onderz. iii., p. 470) gave :■ 



Deducting the sulphur, 

 as S, N H2— 

 C 52-7 52-7 53-8 



H 6-9 6-8 6-9 



N 15-5 14-6 14-9 



23-9 23-9 24-4 



S 1-0 



100- 98-0 100- 



In cow-horns, therefore, the same group exists as in fibrin. 



I have not hitherto spoken of the phosphorus, but it is in the 

 same state as the sulphur. I will make a more correct determina- 

 tion of its small proportion in fibrin, albumen, &c. But it has been 

 found in a remarkable manner, that the phosphorus is in the same 

 condition as the sulphur, viz. : — in the analysis of legumin. Prof. 



