Royal Society, 216 



2nd, Boiled with liquor potassse a very faint pinkish tint was pro# 

 duced ; a few white flakes also fell down. 



3rd. Heated in a water-bath with the blue oxide of copper, in a 

 few minutes the yellowish red powdery suboxide precipitated. 



This reaction took place both in the original albuminous liquid and 

 after the coagulation of the albumen by heat and nitric acid. 



4th. A piece of flannel, saturated with the chloride of tin, was 

 well moistened with the fluid, and then heated over a red-hot coal ; 

 no brown colour of the flannel was produced, such as occurs when 

 grape-sugar is present. (Maumene's test.) 



5 th. A portion mixed in a test-tube with some German yeast was 

 placed for several hours in a warm cupboard, but there was no deve- 

 lopment of gas. 



From these experiments it appears that of the various tests em- 

 ployed, only one gave any indication of the presence of grape-sugar, 

 that test also being the one which is most liable to deception. The 

 lowness of the specific gravity, in which respect this fluid and that 

 analysed by M. Deschamps closely corresponded, would, cl priori y 

 almost lead to the assumption that no grape-sugar was present. 



The presence of the reducing agent could not in this case depend 

 upon any irritation of the origin of the vagus, for the irritation, if 

 any, produced by a spina bifida is at the end of the cerebro- spinal 

 axis furthest removed from the origin of that nerve. That the ma- 

 terial however which eflfects this reduction is of a very changeable 

 nature, was shown by allowing a portion of the fluid to stand for 

 several days until putrefaction had commenced. The fluid was then 

 filtered so as to separate the insoluble albuminous flakes, and the 

 clear liquid heated in a water-bath with the blue oxide of copper ; 

 when, instead of the suboxide being produced, the black anhydrous 

 oxide was formed, just as is the case when the blue oxide is heated 

 merely with water, thus satisfactorily showing that the reducing 

 substance had been destroyed. 



The recent investigations of Virchow* and Buskf have shown 

 that substances of a non-nitrogenous nature exist both in the brain 

 and spinal cord, but they hold somewhat difi^erent opinions respect- 

 ing their exact characters ; for whilst the former considers them to 

 be cellulose, the latter regards them both in their "structural, che- 

 mical and optical properties " to resemble starch. In conformity 

 with these views, it was interesting to determine if any indications 

 of the presence of either of these substances could be found in the 

 cere])ro-spinal fluid ; accordingly a portion of the fluid was evapo- 

 rated nearly to dryness and then divided into two portions ; to one 

 was added an alcoholic solution of iodine and concentrated sulphuric 

 acid, when a violet tint was produced, which after a few minutes dis- 

 appeared ; but it was also found that this same appearance was pro- 

 duced when the acid and iodine solution were mixed together alone, 

 the violet colour being evidently owing to the volatilization of a part 

 of the iodine and the evolution of its characteristic violet tint ; to 

 the other a solution of iodide of potassium and then nitric acid was 



* Quarterly Journal of Microscopical Science, January 1854. f Ibid. 



