54 Improvements in Physical Science [Jan. 
sulphur. The water, with which the charry matter was washed, 
reddened litmus paper. When the water was evaporated, the 
residuum treated with potash yielded ammonia: this residuum, 
being dissolved in water, left a small portion of a substance which 
possessed the properties of silica. From the solution ammonia 
precipitated phosphate of lime, Left to sponianeous evaporation it 
yielded crystals of sulphate of potash, common salt, and phosphate 
of magnesia. The free acid present was the phosphoric. 
The brain, when triturated with potash, gave out ammonia; and 
ammonia was likewise obtained when a mixture of brain, potash, 
and water was distilled. 
When water is boiled with a quantity of brain, then filtered, 
evaporated, and mixed with alcohol, only a little gelatinous matter 
separates. The alcoholic solution in a few weeks deposited crystals, 
which consisted of a greasy matter, phosphate of ammonia, and 
common salt. Alcohol separates the fatty matter very well from 
brain, and the liquid passes readily through the filter when hot. 
The fatty matter of calf’s brains is white. At the same time the 
alcohol dissolves another substanée called by Thenard and Vauquelin 
osmazom. 
The constituents of the cortical portion of the brain of a calf 
were as follows : 
WY EN oe tae Sanese eerie) INS J. | Roh ete po ee fe oe 
Insoluble cerebral albumen with some soluble ditto 10 
Osmazom 
Fatty matter 
Phosphate of lime 
Phosphate of soda 
Phosphate of ammonia sia, ccm & aap Siigin a0 cn opted LR 
Phosphate of magnesia 
A sulphate 
Common salt 
Trace of phosphate of iron 
100 
The medullary portion of the brain contains the same con- 
stituents as the cortical; but the proportion of fatty matter is 
greater, and the cerebral albumen, when treated with alcohol, is 
harder and more fibrous. ‘Traces of silica are also found in it. 
The, medulla oblongata contains the same ingredients as the 
medullary portion of the brain; but less water and more albumen. 
The same observations apply to the thalami nervorum opticorum, 
the cerebellum, and the nerves. 
2. Black Pigment of the Eye.—A curious set of chemical expe- 
riments on the black pigment in the eyes of oxen and calves has 
been published by Leopold Gmelin (Schweigger’s Journal, vol. x. 
p. 507). From 500 eyes of oxen and calves he collected 75 grains 
of this substance. Jts colour is blackish-brown. It is tasteless, 
and adheres to the tongue like clay. It is insoluble in water, 
