268 Mr Fox's Renmrkit on Electric Carrcnfs 



appeared, that, in one instance, the artificial cuiTents pred(>m,i,7i 

 nated ; but in others, in which the ore-points were farther, 

 asunder, the opposing currents either neutralized each other ; 

 or the natural ones were only diminished, not reversed.* 



In my earlier experiments, I used copper wires coated with 

 a solution of sealing wax in alcohol ;■)• but this protection not 

 having been found necessary, was afterwards dispensed with. 



I have been induced to recapitulate the tests and precautions 

 which I adopted, because I conceive, that had they not been 

 overlooked in some quarters, no suspicion could have existed 

 that the electricity observed in mines, might have arisen from 

 the apparatus employed, or at least that it was not fully proved 

 to have been derived from the veins themselves. It is satis- 

 fiictoi-y to find that Professor Reich used similar tests, and 

 that he deems them to have been as decisive on this point as 

 I have done. 



I quite concur with him in considering the phenomena in 

 question to be hydro-electric, and this opinion I have long 

 maintained, J for the indications of electricity in the veins 

 seemed to depend on the existence of imperfect conductors 

 between the masses of ore ; and, moreover, it is found that the 

 different ores, when connected, produce electric cm-rents even 

 in rain-water, and in water taken from the mines, the action 

 is still more considerable. Professor Reich has stated the 

 order in Avhich he found some of the ores to follow each other 

 in their voltaic relations. His series differs very slightly from 

 the one which I have given in the Philosophical Transactions 

 for 1835, p. 39, owing doubtless, to some differences in the 

 specimens which we used in oiu- experiments. Thus I find that 

 different specimens of copper-pyrites, iron-pyrites, arsenical 

 pyrites, &c., vaiy much in these relations with respect to each 

 other ; and ores of the same name ; two pieces of copper-py- 

 rites, for example, in rain-water, will often cause considerable 

 deviations of a sensible needle. Some ores which were partly 



* See Fourth Report of the British Associ.ation. 18:M. p. 573, 

 t Phil. Transactions, 1830, p. 399. 



X Phil. Transactions, 1835, p. 39. Also Fourtli Beport of the Cornwall 

 Polytechnic Society 1836. pp. 127-128 ; or Sturgeon's Annal& of Electricity. 



