THE CENTRAL NERVOUS SYSTEM 



88 1 



The next table shows the variations in the content of water, 

 solids, and protein in different parts of the nervous system 

 (Halliburton) : 



The grey matter of the cerebrum in the adult contains 81 to 

 86 per cent, of water, the white matter 68 to 72 per cent., the 

 brain as a whole 81 per cent., the spinal cord 68 to 76 per cent., 

 and the peripheral nerves 57 to 64 per cent. In the foetus more 

 water is present (92 per cent, in the grey and 87 per cent, in the 

 white matter). 



The superior richness of the grey matter in proteins and the 

 preponderance of water in it, are the chief chemical peculiarities 

 which distinguish it from the white matter. That it should 

 have a high protein content is easily understood, for the proto- 

 plasmic structures, the nerve-cells, are situated in the gre}^ 

 matter. But that the most important functions should have 

 their seat in a tissue containing only 14 to 19 per cent, of solids 

 is surprising, and should warn us that the water is no less signifL 

 * Calculated. f Calculated by difference. 



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