216 Roijal Society. 



added, when a brown colour was i)roduced, owing to the liberation 

 of the iodine. In neither portion could it be said that any evidence 

 of the presence of starch or cellulose was detected. 



A comparative trial was also made between the effects produced 

 upon the blue oxide of copper by the cerebro-spinal fluid, solutions 

 of grape-sugar, cane-sugar, starch, cellulose, and mannite, an unfer- 

 mentizable sugar. These various substances were heated in a water- 

 bath for the same length of time, when it was found that whilst the 

 grape-sugar eiFected a reduction immediately, and the cerebro-spinal 

 fluid only after the lapse of several minutes, neither the starch, cellu- 

 lose, cane-sugar nor mannite effected any reduction at all. 



The power of reducing the blue oxide of copper is not confined to 

 non-nitrogenous substances, for I found that if a solution of leucine* 

 be heated along with it in the usual manner, the reduction is effected 

 in about the same length of time, and in the same way as by the 

 cerebro-spinal fluid. This single experiment is not of itself sufficient 

 evidence that the reducing power in both cases depends upon the 

 presence of the same substance. Such an assertion could only of 

 course be proved by obtaining from the cerebro-spinal fluid leucine 

 in the crystallized form. A proper quantity of the fluid was not, 

 however, left to investigate this point. 



From the above experiments I think it may be safely asserted that 

 the power possessed by the cerebro-spinal fluid of reducing the oxide 

 of copper, is not owing to the presence either of grape-sugar or any 

 of the allied substances : whether it may depend upon the presence 

 of leucine or other modifications of albumen of a somewhat similar 

 nature, or whether it may be due to the presence of a substance be- 

 longing to another series, is a point that has yet to be determined. 



Note hy Mr. Paget. — The patient from whom the fluid analysed 

 by Mr. Turner was obtained, was a girl born of healthy parents. An 

 infant cousin had lately died from the same congenital defect as she 

 presented. The upper part of the body was well formed, but the 

 pelvis and lower limbs were small and nearly powerless. The sac 

 containing the fluid was seated over the last lumbar vertebra, pro- 

 jecting (as the examination after death showed) through an opening 

 between its unclosed arches. It enlarged quickly after birth, but did 

 not evidently affect the child's health, unless it were connected with 

 a very frequent spasmodic action of the muscles closing the glottis, 

 which, almost from the time of birth, had produced the peculiar 

 '* crowing inspiration," or laryngismus stridulus. The fluid was first 

 withdrawn when the child was three months old. Neither on this, 

 nor on any subsequent occasion, did its removal produce any mani- 

 fest effect, although the flaccidity of the emptied sac indicated that 

 the pressure upon the spinal cord was greatly diminished. After every 

 evacuation the sac very quickly filled again, notwithstanding pressure 

 exercised upon it. 



* Leucine C'^NH'^O^, a weak base, belonging to the same series as glycocine 

 and alanine, is generally obtained by the decomposition of albuminous substances. 

 It has been obtained by Scherer from the spleen, and, according to Gregory, has 

 been detected as a natural product in the liver of the Calf. 



