APPENDIX 277 



effect in the production of a disease which it is impossible 

 to determine, but so many factors are concerned in the 

 matter that confusion and contradiction in the conclusions 

 reached are inevitable." (Ward, 1908.) 



All this is very interesting and true, but it does not 

 answer my question as to the relative effect, if any, of 

 non-conducting and conducting soils other things being 

 equal upon certain specified diseases, and I am afraid that, 

 so far, nothing of value upon this subject has been pub- 

 lished, probably not even recorded. 



This much, however, is known to a few submarine 

 cable electricians. A simultaneous observation taken at 

 eighteen stations in 1912, and my own results during this 

 year, gave the maximum earth-current as eight volts, and 

 this can, in all probability, be accepted as the normal maxi- 

 mum, for fairly short cables, in the absence of magnetic 

 disturbances. Long cables, on the other hand, not infre- 

 quently exhibit currents of comparatively high tension, 

 and this may be explained by the greater area traversed 

 by them. 



ELECTRICITY IN RELATION TO SOME 



VEGETABLE POISONS. 



\ 



I have read recently of persons being poisoned by 

 rhubarb leaves, boiled and eaten as a vegetable. My 

 research work has taught me what to avoid in vegetarian 

 diet, although I am not a vegetarian, and we my 

 people and I have enjoyed rhubarb leaves for years. 

 They are, however, always more or less aperient, and 

 should be eaten in moderation. 



The subject of vegetable-poisoning in relation to 

 dietary and habit is one of interest and importance, and I 

 am glad to be able to throw some light upon it. 



All vegetable toxins, so far as my experiments have 



