582 BRAIN AND NERVES. 



increased until the second year, but from this age to the nineteenth 

 year the quantity was the same. 



The older analyses of PETROWSKY and of BAUMANN 1 are not sufficient 

 for present conditions, but they substantiate in substance what has been 

 stated (page 575) in regard to the unequal division of the organic con- 

 stituents between the gray and white substance. 



BAUMSTARK claims to have found that a part of the cholesterin in 

 the brain occurs in a combined state, perhaps as ester; this view has 

 been found to be incorrect by the recent investigation^ of BUNZ. He 

 obtained from the brain neither esters of cholesterin with higher fatty 

 acids nor other compounds of cholesterin which split on saponification. 

 TEBB 2 has also found only free cholesterin. 



The analysis of the brain of an epileptic made by KOCH 3 is of very 

 great interest. As the protagon is considered by KOCH as a mixture, no 

 results for the quantity of protagon are given. As no accurate methods 

 for the estimation of the little known bodies cephalin, myelin, phrenosin 

 and kerasin are available, the figures given for these are of little value. 

 The following results are calculated to 1000 parts: 



Corpus Cortex 



Callosum (prefrontal). 



Water 679.7 841.3 



Protein 32 . 50. 



Nucleoproteins 37.0 30.0 



Nuerokeratin 27.0 (CHITTENDEN) 4.0 (CHITTENDEN) 



Extractives (water-soluble) 15.1 15.8 



Lecithins 51 . 9 31 .4 



Cephalin and myelin 34.9 7.4 



Phrenosin and kerasin. ... 45.7 15.5 



Cholesterin 48.6 7.0 



Sulphurized substance. ... 14.0 14.5 



Mineral bodies 8.2 8.7 



As the cerebrosides chiefly occur in the myelin sheath, KOCH, starting from 

 the amount in the investigated part of the brain, attempts to calculate the amount 

 of the analyzed cortical substance in the white nerves, and on the basis of these 

 calculations, he finds the following values for the pure gray substance, free from 

 nerve-fibres, and compares them with the corpus callosum. The results are in 

 1000 parts of the dry substance: 



Gray Substance 



Corpus (free from 



Callosum. white substance). 



Protein 100.0 217.0 



Nucleoproteins 115 . 6 96 . 6 



Neurokeratin 84 . 



Extractives 47 . 5 59 . 2 



Lecithins 162 . 2 76 . 7 



Cephalin and myelin 109 . 1 



Phrenosin and kerasin r 142 . 9 



Cholesterin 152 . 



Sulphurized substance 43 . 7 54 . 3 



1 Petrowsky, Pfliiger's Arch., 7; Baumann, Zeitschr. f. physiol. Chem., 9. 



2 Bimz, Zeitschr. f. physiol. Chem., 46; Tebb, Journ. of Physiol., 34. 



3 Amer. Journ. of Physiol., 11. 



