PROTEIN. 175 



combustion it gave out a smell analogous to saffron. The com- 

 bustion was very slow. It was subjected to an ultimate analysis 

 by Mulder. 527 parts of it gave 927 of carbonic acid, and 293 

 of water. 2750 parts of it gave 756 of chloride of silver. Hence 

 100 would have given 27*49 of chloride of silver = 6*87 chlo- 

 rine = 11-62 chlorous acid. The azotic gas was determined 

 by measurement, and was one-eighth part of the bulk of the car- 

 bonic acid gas. Hen^e the constituents are 



Carbon, . 47-97 



Hydrogen, . 6-18 



Azote, . 14-10 



Oxygen, . 20-13 



Chlorous acid, 11-62 



100-00 



He gives as the formula for its composition C 40 H 31 Az 5 O 12 

 -f CIO 3 ; that is to say, an atom of protein and an atom of chlo- 

 rous acid united together. Doubtless the oxygen of the chlorous 

 acid was obtained by the decomposition of three atoms of water. 



When casein or fibrin was used instead of albumen, the com- 

 pounds formed were identical ; showing that the protein from 

 albumen is isomeric with that from casein and fibrin. 



The liquid from which the chloro-proteic acid had been pre- 

 cipitated by chlorine was transparent, very acid, and smelled of 

 chlorous acid, though very little of that acid was present. When 

 saturated with ammonia only two or three bubbles of azotic gas 

 were extricated. Being evaporated to dryness, it left a great 

 quantity of sal-ammoniac. We see from this that the water had 

 been decomposed by the action of the chlorine ; the chlorous acid 

 united to the protein, but the muriatic acid remained dissolved 

 in the water. 



Dry chloro-proteic acid is a straw-yellow powder with a fatty 

 feel. It is insoluble in alcohol and ether, and almost insoluble in 

 water. In concentrated sulphuric acid it dissolves without com- 

 municating any colour. When water is added to the solution 

 white flocks precipitate. When nitric acid is made to act upon it 

 for several days at the common temperature of the atmosphere 

 it gradually dissolves it, and converts it to xanthoproteic acid. 

 When acted on by muriatic acid cold, it is not converted into hu- 

 min as is the case with protein. It forms in it a colourless solu- 

 tion. 



