On the Protein Question, 16S 



pendent organic group, which is free from sulphur in evert/ sense of 

 the word. 



If, for instance, a current of chlorine is passed through a solution 

 of albumen, for several days together, wo obtain not a product of de- 

 composition, but a real combination of chlorous acid with protein, 

 which does not blacken silver. The quantity of sulphur it contains, 

 in the form of hyposulphurous acid, is equal to that of the sulph- 

 amid of an equivalent quantity of albumen. According to Kemp, 

 this would amount to 1'5 per cent, in the chlorite compound; but 

 this is too high, as I shall prove below. If duly prepared, it does 

 not contain more than 1*2 of sulphur, equal to 1"83 per cent, of hy- 

 posulphurous acid. 



But this proportion is far from being constant or essential ; for if 

 a current of chlorine is passed through the acetic acid solution, from 

 which protein from fibrin has been precipitated, we obtain a chlorito 

 of protein, perfectly similar to that from albumen, but containing 

 only 0*4 per cent, of sulphur =0*6 per cent, of hyposulphurous 

 acid. 



Similar discrepancies are found in the quantity of hyposulphurous 

 acid, existing in protein itself. 



After this sulphur question has produced it^ effect, it will descend 

 into the place which it ought to occupy. 



The maximum quantity of hyposulphurous acid which I have been 

 able hitherto to find in, or to be taken up by protein, is 2*4 per cent., 

 equal to 1'6 per cent, of sulphur — that is the quantity which is found 

 in albumen, under the form of sulphamid. It represents exactly the 

 half, in equivalents, of the quantity of hydrochloric acid, that can be 

 taken up by albumen. This combination, therefore, cannot be called 

 strange or singular. The hyposulphurous acid obstinately adheres 

 to the protein in the same manner as sulphuric acid, phosphate of 

 lime, metallic oxides, and several other bodies, all of which may 

 unite with it in small quantities. 



The composition of protein, free from sulphur in every form, 

 may bo represented by the following empirical formula : — 



C36 H25 N^ O^o + 2 H 0. 



It difiers from the ono to which I have hitherto adhered, because 

 the organic group contains a little less nitrogen than was ascribed to 

 it before. This is all the modification which my former results re- 

 quire. 



The formula expresses in 100 parts. 



The grounds upon which I propose this formula, are not more 



