158 OLEOPHOSPHORIC ACID. 



4. The nerve-cells contain a substance resembling 

 caseine. 



5. The " sheath" of the nerve-fibres appears to 

 consist of elastic tissue (q. v.). 



(See Brain and Oleophosphoric Acid.) 



Oleophosphoric Acid (Fremy). 1. The ethereal ex- 

 tract obtained in the preparation of cerebrine (q. v.) is 

 evaporated and digested with a small quantity of ether. 

 The solution must be shaken with dilute sulphuric acid 

 to remove soda, then washed with water to remove 

 excess of acid. Distil off the ether, and dissolve the 

 residue in boiling alcohol; on cooling the oleophos- 

 phoric acid will be deposited, and must be freed, as far 

 as possible, from oleine by washing with cold absolute 

 alcohol, and from cholesterine by ether, in which the 

 latter is the more soluble. 



2. Sodium oleophosphate may also be obtained from 

 muscle, &c., by extracting with cold dilute alcohol, 

 and treating the extract as above. 



3. Oleophosphoric acid is a yellowish viscous sub- 

 stance, soluble in ether and in hot alcohol, insoluble in 

 cold absolute alcohol and in water, but swelling up 

 slightly in boiling water from the presence of a little 

 cerebric acid. 



4. Long boiling with water or alcohol, especially if 

 acidified, decomposes it into oleine and phosphoric acid, 

 or into oleic and glycerophosphoric acids. The same 

 change takes place in the brain by physiolysis or 

 putrefaction. 



