68 STUDIES IN ELECTRO-PHYSIOLOGY: 



electro-plated at the same time in the same vat and with 

 the same metal, the possibility of any dissimilarity is 

 reduced to a minimum. Furthermore, contact with the 

 body is not made for a sufficient time for polarisation to 

 occur. In addition to that the conditions are not identical. 

 In a galvanic cell or battery there are only two terminals, 

 positive and negative. In the human hands there are four 

 terminals a positive and negative to each hand and this 

 would again tend to check polarisation, even with inferior 

 electrodes. 



With these observations it may safely be left to the 

 impartial reader to hold the scales between physiologist 

 and physicist. I have laboured the point at length 

 because it lies at the root of the whole matter. This, as I 

 believe, untenable theory of two, alleged, dissimilar metals 

 in the presence of moisture has not only hampered progress 

 during the past century, but is even now being put forward 

 to bar our way to enlightenment. 



The second theory that of one metal in two dis- 

 similar solutions is, I venture to think, sufficiently 

 disposed of by the electrical response of earth-grown 

 and pot-grown plants and fruits, and calls for no further 

 remark. 



Suggestion. In much the same way that the average 

 cable electrician has been accustomed to attribute certain 

 galvanometric deflections to " leakage," some physiologists 

 seek to find in " suggestion " an explanation of many of 

 the proofs of successful treatment which have been brought 

 forward. In taking cardiograms by means of the string 

 galvanometer psychological influences cannot be dis- 

 regarded, because the heart can be psychologically in- 

 fluenced through the cardiac branches of the vagi, but, by 

 my method of testing, the deflections registered by gal- 

 vanometers of the Kelvin or d 'Arson val type are only 

 subject to variation by differences of pressure upon the 



