BRAIN 



323 



Nitrogen Content. Using trichloracetic acid for extracting 

 water soluble organic substances from nerve tissue, Hatai ('17 a) 

 has determined the content of total nitrogen and of non-protein 

 nitrogen in the entire brain of the Albino at different ages. The 

 data are arranged hi table 180. 



In chart 58 a graph is presented for the non-protein nitrogen 

 per gram of dried brain at different ages. 



180 



160 



140 



120 



100 



180 



200 220 



Chart 57. Giving in milligrams the absolute weight of the more important 

 chemical constituents of the brain. Plotted on age. Table 179. 



Hatai ('17 a) followed at two ages the distribution of nitrogen 

 in the three divisions of the brain and in the spinal cord. His 

 results are given in tables 181 and 182. 



When the lipoids have been removed (Hatai, '17 a) it appears 

 that in the several divisions of the nervous system the relation 

 between the protein nitrogen and the nitrogen content of the 

 extractives is nearly constant as shown hi table 183. 



