102 NERVOUS SYSTEM. 



the white fatty matter of Yauquelin, the myelocone of Kuhn ; 5. Cere- 

 bral cholesterin cJwlesterote ; and the salts found by Vauquelin, 

 lactic acid, sulphur, and phosphorus, which form a part of the fats 

 above-mentioned. 1 In the spinal cord, there is more fatty matter, and 

 less osmazome, albumen, and water. In the nerves, albumen predomi- 

 nates, and fatty matters are less in quantity. Researches by M. Las- 

 saigne show, that water constitutes T 7 oths of the nerves; and T 8 G ths of 

 the brain ; whilst the proportion of albumen in the former is T 2 o 2 u tns > * n 

 the latter, T J^ths. He found the neurine of different parts of the brain 

 to be composed as follows : 



The whole Brain. White portion. Gray portion. 



Water, 77-0 73'0 85-0 



Albumen, 96 9-9 7-5 



White fatty matter, 7-2 13'9 1-0 



Red fatty matter, 3-1 O9 3-7 



Osmazome, lactic acid, and salts, 2-0 10 1-4 



Earthy phosphate, M 1-3 1-2 



100-0 100-0 1000" 



M. RaspaiP has pointed out two other differences. First, when a 

 nerve is left upon a plate of glass in dry air, it becomes dry, without 

 putrefying, whilst cerebral neurine putrefies in twenty-four hours ; and 

 secondly, the dried nerve has all the physical characters of the corneous 

 substances, nails, hair, and other analogous bodies ; and in their 

 chemical relations, these bodies do not differ sufficiently to repel the 

 analogy. Neither the chemical analysis of neurine, nor inquiry into 

 its minute structure by the aid of the microscope, has, however, thrown 

 light upon the wonderful functions executed by this elevated part of 

 the organism. 



It would seem, that neurine is, in composition, intermediate between 

 fat and the compounds of protein : it contains nitrogen, which is not 

 present in fats, but in smaller proportion than in protein ; and, on the 

 other hand, it is much richer in carbon than protein or its compounds. 

 Phosphorus, too, is an essential ingredient. According to recent re- 

 searches by M. Fremy, there is in cerebral neurine a peculiar acid, ana- 

 logous to the fatty acids, which he calls cerebrie acid, and which contains 

 nitrogen and phosphorus : this is mixed with an albuminous substance ; 

 with an oily acid oleo-phosphoric ; with cholesterin; and with small 

 quantities of olein and margarin, and oleic and margaric acids. 4 



To the naked eye, neurine appears under two forms ; the one gray 

 and of a softer consistence ; the other white, and more compact. The 

 former is called the vesicular, gray, cortical, cineritious, or pulpy sub- 

 stance ; the latter, the tubular, white, medullary, or fibrous, called 

 "tubular" in consequence of its consisting of tubes of great minuteness, 

 which are filled with a kind of granular pith that can be squeezed from 

 them, a view adopted by most histologists. Dr. James Stark has, 5 



1 For John's Analysis of the white and gray cerebral matter, see Journal de Chimie Medi- 

 cale, Aout, 1835. See, also, Simon's Medical Chemistry, p. 81, Lond., 1845. 



a Journal de Chim. Medic.; and Pharmaceutisches Central Blatt, Nov. 19, 1836, s. 765. 



3 Chimie Organique, p. 217, Paris, 1833. 



4 Journ. des Connais. Med.-Chir., Jan., 1841 ; also Turner and Liebig's Chemistry, 7th 

 edit., p. 1195, Lond., 1842. 



6 Proceedings of the Royal Society, No. 56, Lond., 1843. 



