On the Protein Question. 167 



I have, for simplicity, left out tho phosphorus ; I do not even know 

 if it exists in this compound. 



II. 



The quantity of sulphamid in fibrin and casein is different from 

 that in albumen, but the difference is small, and therefore I pass it 

 over here. 



These bodies are the chlo rites of albumen, fibrin, and casein. 

 They produce sulphuret of silver, on being heated with potash upon 

 silver, and thus they can be easily distinguished from the chlorite 

 of protein containing hyposulphurous acid, which does not possess 

 this property. 



The latter may be prepared in different ways — among others, from 

 the solutions, from which protein has been precipitated, or by pass- 

 ing chlorine, for a long time, through a mixture of albumen, fibrin, 

 casein, horn, hair, whalebone, &c., and water. The product always 

 contains a certain quantity of hyposulphurous acid arising from the 

 decomposition of sulphamid and water 2 (S N H' + H 0). The ac- 

 tion of the chlorine upon this produces ammonia, which unites with 

 hydrochloric acid, — and hyposulphurous acid, which, along with chlo- 

 rous acid, is taken up by the organic compound. 



In my former letter to you, I reduced the composition of protein 

 with hyposulphurous acid, as it is obtained from albumen, to a group 

 free from this mixture. I then brought into account 1*4 per cent, 

 of sulphur, as was found by Fleitmann. The normal quantity ob- 

 tained by fusion with soda, and subsequent addition of saltpetre, is 

 1 '6 per cent., and this I believe to be the true proportion of sulphur 

 in albumen. The compound consists of — 



