CHAP. X.] THE NERVOUS TISSUES. 437 



(B) Strecker : l 



3 5 o 



0-C 2 H 4 -N(CH 3 ) 3 OH 



(C) Hoppe-Seyler : 2 



'n 



0-C 2 H 4 -OH 



Distearyl-lecithin may be looked upon as the type of the lecithins ; 

 but we can easily conceive of lecithins which only differ from this one 

 by the radicals of oleic acid or of palmitic acid having taken the 

 place of stearyl. We should thus have dipalmityl-lecithin, dioleyl- 

 lecithin or oleyl-palmityl-lecithin formed ; such bodies probably 

 exist. 



Phosphorized Principles other than Protagon and Lecithin. 



In a very elaborate research on the phosphorized constituents of 

 the brain, Thudichum 3 has come to the conclusion that he has 

 separated at least three well characterized bodies or groups of bodies. 



The bodies belonging to these groups are distinguished as (1) the 

 Kephalines, (2) the Myelines, (3) the Lecithins. 



Ke haiine Belonging to the first group is a body Kephaline, 



which is said to be exceedingly soluble in ether ; this 



body is soluble in hot alcohol, but less so than either lecithin or 



myeline. To kephaline is ascribed the formula C^H^NPC^. It does 



not form definite compounds with platinum or cadmium. 



Myelines ^ e m yelines are far less soluble in ether than 



kephaline or the kephalines, and less soluble in alcohol 

 than the lecithins. 



Various myelines have been described by Thudichum including 

 bodies having the following formulae : CJ&g-NPOg ; C^H^NPO^; 

 CUWO,.; Q.BUN.PO,; C M H 81 NPO S ; C^N,PO, 



Thudi- The following are the main characters of the phosphorized 



chum's sum- principles of the brain as summarized by Dr Thudichum. In 



mary of his quoting them the author in no respect expresses his agree- 



researches on ment with Dr Thudichum's conclusions. 



" The S rou P f the P hoa P horize(1 bodies contains the 

 ciples phosphorus in the form of phosphoric acid, combined proxi- 



mately with glycerine, so that by chemolysis they all yield 

 glycero-phosphoric acid, but they differ in the manner in which they 

 contain the nitrogen, and the acid radicles which constitute the great bulk 



1 Ann. Chem. Pharm., 18G8, Bd. CXLVIII. s. 77. 



2 Physiologische Chem., 1877, 1 Theil. s. 80. 



3 Thudichum, " Besearches on the Chemical Constitution of the Brain." Reports of 

 Medical Officer of the Privy Council and Local Government Board, 1874, p. 113 et seq. 



