98 CEREBfttC ACID. 



alum, mercuric chloride, or tannic acid. A precipitate 

 will appear in the cold. 



8. Dissolve moist caseine in acetic acid. Add solution 

 of potassium ferrocyanide or chromate ; the caseine will 

 be precipitated. 



9. Dissolve moist caseine by warming in concentrated 

 hydrochloric acid. The solution will have a fine violet 

 colour. 



10. Expose moist caseine to the air. It will putrefy, 

 and yield similar products to fibrine (see fibrine). 



11. Boil caseine with caustic potash. Ammonia is 

 evolved. To the liquid add lead acetate. A black 

 precipitate will prove the presence of potassium 

 sulphide. 



Cerebric acid (Fremy's). 1. Brain is cut into small 

 pieces, treated repeatedly with boiling alcohol, and left 

 for some days in alcohol, to remove water, then 

 pressed, pounded, and extracted with boiling ether, 

 which dissolves cerebric acid and other substances. 

 Distil off the ether, and exhaust the residue with cold 

 ether to remove cholesterine and leci thine (q. v.). Boil 

 with absolute alcohol acidified slightly with sulphuric 

 acid, and filter hot. The deposit formed on cooling 

 must be washed with cold ether to remove oleo -phos- 

 phoric acid (q. v.), and the remaining cerebric acid 

 purified by recrystallisation from boiling ether. 



2. White crystalline granules, swelling up like 

 starch, but not dissolving, in boiling water, insoluble 

 in cold, soluble in hot alcohol and ether. From the 



