346 Analysis of the Cerelral Matter ofMaUy ^c, [May, 



The solution of nerve in alkali is precipitated by acids, and 

 the precipitate, as well as the liquid from which it fell, assumes 

 a purple colour. 



Nerve preserved in water undergoes little alteration. The 

 water, however, after a few days, assumes the odour of semen 

 very sensibly. 



Nerve put into oxymuriatic acid contracts its dimensions. As 

 it is chiefly the envelope of the nerves which undergoes this 

 change, the nervous substance issues from its case, and each of 

 the tibres which compose it separates from those in its neighbour- 

 hood : >-o that the nerve looks like a hair-pencil with its extre- 

 mities diverging. In this situation the substance of the nerve 

 assumes more consistence and whiteness, owing to the condensa^ 

 lion and opacity which it requires. From this experiment, it 

 would seem that oxymuriatic acid would furnish a good instru- 

 sjient for facilitating the study of the nerves and their evelope. 



Is it possible, from the experiments to which the brain has 

 been subjected, to determine the state in which each of the 

 elements composing this organ exists in it? Is not the albumen 

 united to a portion of phosphoric acid, and is not its consistence 

 and opacity owing to this combination? Without affirming any 

 thing on this head, I will say, that this substance appears to 

 have acquired its state of semicoagulation from an acid ; just as 

 happens to the curdy part of sour milk j and that this coagulation 

 is produced entirely by a fermentation, v/hich commences like 

 that of milk, by being acid. 



I next proposed to myself this question. Is the fatty matter in 

 combination with the albumen and the osmazome ? This seems to 

 be the case, at least with regard to the fatty matter and albumen ; 

 for when the matter of brain is triturated with water, and converted 

 into a species of emulsion, if it be left at rest the albumen and 

 fatty matter separate together, and the osmazome remains in 

 solution in the liquid, together with a small portion of the 

 albumen. At the same time, I acknowledge that it is possible 

 that these two substances are only in the state of mixture, and 

 that the albumen here performs the same office to the fatty 

 matter that mucilage* does to the oils of emulsive seeds, 



* I call mucilage, with all the chemists, the substance which hplds the oil 

 in suspension in the emulsion of alnipndsj though it be of a very differeut 

 nature frooi gum. 



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