THE BRAIN. 143 



Water, - - - 80.00 



White fatty matter, 4.53 



Reddish fatty matter, - 0.70 



Albumen, - - - 7.00 



Osmasome, 1.12 



Phosphorus, - 1.50 



Acids, salts, and sulphur, 5.15 



100.00* 



In professor JOHN'S examination of the cineritious mat- 

 ter of the brain of a calf, he detected the following salts : 

 muriat of soda, a sulphat, the phosphats of lime, soda, 

 ammonia, and magnesia, with a trace of the phosphat of 

 iron, and silica }. 



The brain in consequence of its structure, is usually di- 

 vided into two portions, termed Cerebrum and Cerebellum. 

 The CEREBRUM occupies the whole frontal, coronal, and 

 a great part of the occipital portion of the skull. Its peri- 

 pheral portion consists of cineritious matter ; its central, of 

 medullary, here and there mixed with cineritious. Its 

 surface is marked by numerous furrows, of various depths, 

 and which are convoluted in different directions. It is di- 

 vided longitudinally and vertically, by a deep fissure, which 

 receives a duplicature of the dura mater, into two nearly 

 equal portions, which are termed Hemispheres. These are 

 convex externally, irregular beneath, and flat on the oppos- 

 ing surfaces. Each hemisphere is divided into three lobes ; 

 the anterior, which rests on the orbital plate of the frontal 

 bone ; the middle, occupying the cavity formed by the 

 sphenoid and temporal bones ; and the posterior, which oc- 

 curs nearest the neck, and rests on the cerebellum. In de- 

 scending between the two hemispheres, towards the centre, 



* Annals of Phil, iii, p. 27. f Jb. viL p. 54. 



