296 Is Choline present in the Cerebro-Spinal Fluid of Epileptics ? 



reagents employed. It must be remembered that the delicacy of the 

 polarisation microscope is so great that impurities which cannot be 

 detected by ordinary chemical methods are revealed. Whilst it may of 

 course be possible to purify the salts used in the test to such a degree that 

 they are free from these impurities, I have been unable up to the present 

 to obtain any specimens which do not show some anisotropic crystals 

 under the conditions of Donath's method. Kahlbaum's purest potassium 

 chloride and potassium carbonate give the reaction easily. 



Whilst this investigation was in progress a paper appeared by 

 A. Ziveri^ on the presence of choline in cerebro-spinal fluid in mental 

 diseases. By applying Rosenheim's periodide test, he found choline 

 absent in cases of epilepsy, only one positive result being obtained in 

 twenty-six examinations. 



The conclusions arrived at by M. Kauf mann,'^ so far as they refer to 

 the absence of choline in epilepsy, confirm my results ; but his further state- 

 ments that the base found by him in cerebro-spinal fluid in other cases Is not 

 choline do not seem to be borne out by his own experiments, and are not in 

 agreeiiient with the results of previous observers and my own. 



The following are the general conclusions to be drawn from the 

 investigations : — 



1. Rosenheim's periodide test for choline is both trustworthy and 

 sensitive. 



2. Relying upon this test, choline is found to be absent from the 

 cerebro-spinal fluid in cases of genuine epilepsy. 



3. The detection of a few fragments of anisotropic crystals by 

 Donath's raicro-polariscopic test is not in itself sufficient evidence of the 

 presence of choline in the cerebro-spinal fluid of epileptics ; for the same 

 result may be obtained with normal cerebro-spinal fluid, or even with 

 distilled water. 



' Riv. di Neuropatologia, etc., vol. i. p. 1, 1908. 



« Neurolog. Zentralbl., Na 6, March 1908, p. 280. The errors iu Kaufmann's 

 experiments have been fully demonstrated by J. Donath in a paper which will be 

 published in the forthcoming number of the same Centralblatt, an advance proof of 

 which has reached me through the kindness of Dr Donath. 



