444 CHOLESTERIN. EXTRACTIVES. SALTS. [BOOK T. 



being performed on a microscopic slide, and the results may be 

 watched under the microscope. 



3. When cholesterin is dissolved in chloroform, and the chloro- 

 formic solution is shaken with an equal volume of strong sulphuric 

 acid, the chloroform becomes successively blue, red, cherry-red, and 

 ultimately purple, whilst the subjacent sulphuric acid acquires a 

 marked green fluorescence. 



4. When heated gently with a mixture of one volume of solution 

 of ferric chloride and two volumes of hydrochloric acid, cholesterin 



assumes a violet or blue colour. 



* 



Cholesterin is a monad alcohol, and it readily forms 



compounds with certain acids as with the volatile fatty acids. 



tives of cho- ^^ ^ e ac ti n of bromine upon cho! ester in, both bodies 



lesterin being dissolved in carbon disulphide, Cholesterin dibromide 



(CaH^OBrj) is formed. 



By the action of phosphorus pentachloride on dry cholesterin, cholesteryl 

 chloride C^H^Cl is obtained. By the action of an alcoholic solution of 

 ammonia upon the chloride, cholesterylamine CggH^NHo is obtained. By 

 treating a boiling alcoholic solution of cholesteryl chloride with sodium 

 amalgam, a crystalline carbo-hydrate having the composition C H and 

 a melting point of 90, is obtained. 



By the action of boiling nitric acid on cholesterin, cholesteric acid 

 is obtained, C 8 H 10 O 5 . This body is one of the substances obtained when 

 cholic acid is oxidized in a similar manner. 



When oxidized by means of chromic acid, cholesterin yields oxycholic 

 acid, C^H^Oe. The two last compounds establish a close relationship 

 between cholesterin and the bile acids. 



SECT. 7. EXTRACTIVE MATTERS OCCURRING IN THE NERVOUS 

 TISSUES WHICH ARE COMMON TO THESE AND TO OTHER TISSUES, 

 ESPECIALLY THE CONTRACTILE. 



It is a fact worthy of notice that the brain contains considerable 

 quantities of the same bodies which are found in muscle, viz. crea- 

 tine, xanthine, hypoxanthine, inosit, and lactic acids ; in addition 

 it contains leucine, uric acid and probably urea. 



According to W. Mttller 1 the quantity of inosit in ox brain 

 amounts to 0'8 parts per 1000. The same author separated 0'6 grms.pf 

 uric acid from 50 pounds of ox brains. Mtiller found creatine in 

 the brain of man, but not in that of the ox. 



The quantity of lactic acid separated from ox brain is said to 

 amount to 0'5 per 1000, and, strangely, to be identical with the lactic 

 acid of fermentation. As Kuhne has remarked, this lactic acid may 

 take its origin from the inosit of the brain. 



1 Muller, Annal der Chemie u. Pharm. t Vol. cm. (1857), p. 131. 



