70 ANIMAL ACIDS CONTAINING AZOTE. 



and albumen. He succeeded in obtaining it pure by the follow- 

 ing process. 



He digested the mass obtained by evaporating the etherial solu- 

 tion of the brain in a great quantity of ether. By this means a 

 white substance is precipitated, which is isolated by decantation, 

 and which, when exposed to the air, is transformed into a waxy 

 and fatty matter. This precipitate contains cerebric acid, often 

 combined with phosphate of lime, or soda, and with albumen* 

 It was dissolved in boiling absolute alcohol slightly acidulated 

 by sulphuric acid. The sulphates of lime and soda, with some 

 albumen, remained in suspension, and were separated by the fil- 

 ter. The cerebric and oleophosphoric acids were held in solution, 

 and were deposited as the liquid cooled. The precipitate was 

 washed with cold ether, which dissolved the oleophosphoric acid, 

 and left the cerebric. Finally, the cerebric acid was dissolved 

 in boiling ether, and crystallized three or four times. It was 

 then pure. 



Thus obtained it is white, and composed of small crystalline 

 grains. It is entirely soluble in boiling alcohol, almost insolu- 

 ble in cold ether, but more soluble in that liquid when boiling 

 hot. It has the remarkable property of swelling like starch in 

 boiling water, though it is quite insoluble in that liquid. When 

 strongly heated it melts, but its fusing point is very little lower 

 than that at which it undergoes decomposition. 



When heated in the open air it burns, giving out a characte- 

 ristic odour, and leaving a charcoal which burns with difficulty, 

 and which is sensibly acid. Sulphuric acid blackens it. Nitric 

 acid decomposes it very slowly. When calcined with nitre and 

 carbonate of potash, no sulphate of potash is formed ; a proof 

 that it contains no sulphur. But phosphoric acid is always formed 

 in. such quantities as may be determined. 



When heated with an excess of potash, ammonia is disengag- 

 ed, proving the presence of azote. 



This acid was analyzed by Fremy in the usual way. He found 

 the constituents to be 



Carbon, . 66-7 



Hydrogen, . 1 0-6 

 Azote, 2-3 



Phosphorus, . 0-& 



Oxygen, . 19-5 



100-0 



