NOTES TO VOL, III. 557 



V. We quote the following determinations of the amount of 

 phosphorus in human brain-fat. 



Man aged 59 years. Bright's disease. 

 100 parts of fat from 



The medulla oblongata contained .... .... 1'Co of phosphorus. 



The cerebellum and Pons Verolii contained.... 1'83 



The crura cerebri .... 1'7G 



The hemispheres .... 1*83 



The corpora striata .... 1*65 



The optic thalami .... 1*54 



The corpus callosum .... 1'54 



The mean for all the parts being .... l'G8 



In a girl aged 19 years, the mean quantity was 2'53 ; in a man 

 aged 65 years, who died from marasmus senilis, 1'72 ; in a 

 man aged 80 years, who died from old age, 1*93; and in a man 

 aged 25 years, 1*89. 



In three cases of insanity, the patients being men of the 

 respective ages of 36, 38, and 52 years, the percentage of phos- 

 phorus in the brain-fat was 1*75, 1*93, and 1*87- 



Von Bibra draws the following conclusions from his numerous 

 analyses : 



1. The amount of phosphorus in the brain-fat is very nearly 

 the same in man, in other mammals, and in birds. With the 

 exception of a single case, that of the chamois, in which it 

 amounted to 3'40, it never exceeded 3'Og, and it never sunk below 

 I'OJ, except in Falco nisus, in which it was as low as 0'72-g-. 



2. The phosphorus in the brain-fat of insane persons does not 

 exceed the mean amount ; nor does extreme old age modify the 

 quantity. 



3. The brain in very young persons, and in the embryo, 

 presents no peculiarity in this respect. 



4. The fat of the grey matter contains rather more phosphorus 

 than that of the white substance of the brain. 



Von Bibra believes that the phosphorus of the brain belongs 

 to one of the brain-fats, and in part unquestionably to the 

 cerebric acid, and that consequently its amount varies in different 

 brains with the amount of fat : there is, however, no reason to 

 believe that there is any special connexion between the intelli- 

 gence and the amount of phosphorus. 



VI. The grey and white matter of the human brain were 

 separately analysed by von Bibra. We quote his analysis in the 

 case of a man aged 30 years, who died from pulmonary phthisis. 



