ITS CHEMICAL CONSTITUTION. 117 



We were not in possession of any very carefully conducted 

 investigations respecting the amount of water and fat present 

 in different parts of the brain, until the subject was recently 

 undertaken under Schlossberger's superintendence by Hauff and 

 Walther,* and by von Bibra. f These investigations have led 

 to results which are on the whole of a very conclusive and accor- 

 dant character. It is perfectly established that the white substance 

 of the brain is much poorer in water and richer in fat than the grey 

 matter. With reference to individual portions of the brain, the 

 quantity of water seems to stand in an inverse ratio to that of the 

 fat. In the cortical substance of the hemispheres Hauff and 

 Walther found from 85 to 86 g- of water, and only from 4'8 to 4'9 

 of fat; and von Bibra from 84 to 88^ of water, and from 5*5 to 

 6'5-g- of fat ; whilst the former of these observers found 70'2ir of 

 water, and from 14*5 to 15'5 g- of fat in the white substance of the 

 corpus caliosum, the latter obtained from 63*5 to 69'2 of water, 

 and from 20 to 21$ of fat. On comparing the quantity of fat and 

 water found by these analysts in the different parts of the brain, 

 we find that it may be pre-determined with tolerable accuracy 

 according to the relative amount of the white and grey substances. 

 The same relation was found to exist not only in man, but in all 

 animals in which the brain is sufficiently large to admit of the 

 analysis of the separated grey and white matter for fat or water. 

 Moreover LassaigneJ had previously found that the grey substance 

 was richer in water than the white, the former yielding 85'2-g-, and 

 the latter only 73*0^ of water. 



Von Bibra found that in man, as in most animals, the greatest 

 quantity of fat was deposited in the medulla oblongata. 



Vauquelin, as well as Fremy, found that the whole brain (grey 

 and white substance mixed) yielded with tolerable uniformity 80 

 of water and 5^ of fat, whilst Denis found only about 78 or 76f of 

 water, but as much as 12 or 13$ of fat; von Bibra found on an 

 average 75'54-g- of water and 14*43$ of fat. In animals the quan- 

 tities of water and fat were found to differ considerably. 



Bibra found from 1*5 to 1*9$ of phosphorus in the brain-fat. 



Fremy found 7 ^ albuminous matter in the brain ; and 

 Lassaigne 7*5 in the grey cerebral substance, and 9'9$ in the white 

 substance. 



Lassaigne, singularly enough, found only from 2*2 to 2*3$ of 



* Ann. d. Ch. u. Pharra. Bd. 85, S. 42-55. 



t Ibid. p. 201-224. 



J Compt.rend. T. 9, p. 703, ct T. 11, p. 763. 



