x THE PHOSPHO-GLYCO-PROTEIDS 551 



it is precipitated by acetic acid from a salt-free solution. Nitric acid 

 and hydrochloric acid precipitate ; if in excess they redissolve the 

 precipitate. It is further precipitated by alum, copper -sulphate, 

 tannin, and iodide of mercury + potassium iodide, but not by 

 mercuric chloride or by ferrocyanic acid. It gives the reactions of 

 Millon, Adamkiewiez, and the xanthoproteic reaction. Pepsin 

 hydrochloric acid precipitates a nuclein or pseudo-nuclein. Xanthin- 

 bases are not known. When boiled with hydrochloric acid or potash 

 solution there are formed an albuminate, albumoses, and a higher 

 carbohydrate, the ' sinistrin.' This compound, as the name implies, is 

 laevo-rotatory ; it does not ferment, does not reduce, and does not 

 give the iodine-reaction. It is not attacked by ptyalin, but is con- 

 verted by boiling acids into a reducing, dextro-rotatory carbohydrate. 

 These reactions make it impossible to regard helico-proteid as a simple 

 nucleo-proteid. 



