BRAIN AND NERVES. 279 



Quantitative analyses of the brain have also been made by 

 PETROWSKY on an ox-brain and by BAUMSTARK on the brain of a 

 horse. In the analyses of PETROWSKY the protagon has not been 

 considered, and all organic, phosphorized substances were calcu- 

 lated as lecithin. On these grounds these analyses are not of much 

 value from a certain standpoint. In BAUMSTARK'S analyses the 

 gray and the white substance could not be sufficiently separated, 

 and these analyses, on this account, show partly an excess of white 

 and partly an excess of gray substance ; nearly one half of the 

 organic -bodies, chiefly consisting of bodies soluble in ether, could 

 not be exactly analyzed. Neither do these analyses give sufficient 

 explanation of the quantitative composition of the brain. 



The analyses made up to the present time give, as above stated, 

 an equal division of the organic constituents in the gray and white 

 substance. In the analyses of PETROWSKY the quantity of albumin 

 and gelatine-forming substances in the gray matter was somewhat 

 more than one half, and in the white about one quarter of the 

 solid organic substances. The quantity of cholesterin in the white 

 was about one half, and in the gray substance about one fifth, of 

 the solid bodies. A greater quantity of soluble salts and extractive 

 bodies was found in the gray substance than in the white (BAUM- 

 STARK). The following analyses of BAUMSTARK give the most im- 

 portant known constituents of the brain calculated in 1000 parts 

 of the fresh, moist brain. A represents chiefly the white, and B 

 chiefly the gray, substance. 



A. B. 



Water 605.35 769.97 



Solids 304.65 230.03 



Protagon 25.11 10.80 



Insoluble albumin and connective tissue 50.02 60.79 



Cholesterin, free 18.19 6.30 



combined 26.96 17.51 



Nuclein 2.94 1.99 



Neurokeratin 18.93 10.43 



Mineral bodies 5.23 5. 62 



The remainder of the solids probably consists chiefly of lecithin 

 and other phosphorized bodies. Of the total amount of phos- 

 phorus, 15-20 p. m. belongs to the nuclein, 50-60 p. m. to the 

 protagon, 150-160 p. m. to the ash, and 770 p. m. to the lecithin 

 and the other phosphorized organic substances. 



