Mechanical and Galvanic Electricity. 219 



That heat, light, and electricity are all concomitant pro- 

 ducts of electro-chemical reaction, is self-evident. Agreeably, 

 then, to the strict rules of induction, wherefore is the principle 

 last mentioned to be considered as the cause of the others? 



Where is the proof that the heat and light evolved between 

 the " electrodes" are effects merely of electricity ? The fact of 

 the apparently unlimited evolution of heat from a finite portion 

 of wire duly subjected to a voltaic circuit, is inexplicable, con- 

 sistently with the materiality of caloric, unless we suppose the 

 fluid to be derived from the same electro-chemical reaction to 

 which we owe the electricity associated therewith. 



I conceive it to be almost self-evident, that mechanical and 

 voltaic electricity are due to the same fluid, so far as they are 

 strictly electi-ical. The only doubt with me is, whether the 

 very different characteristics of the phenomena produced by 

 the different means alluded to could be explained without sup- 

 posing some other modifying causes. And at all events, from 

 the reasons above given, I am dissatisfied with the explanation 

 that the difference is dependent on quantity and intensity. 



In terminating my observations, I subjoin the following 

 statement of my opinions as heretofore expressed in one of my 

 text-books. 



" It does not appear to me that the production of electro- 

 magnetic phaenomena, both by galvanic and by electrical dis- 

 charges, disproves my opinion, that caloric and electricity are 

 connate and coordinate products of galvanic action. 



As ignition is producible by either discharge, whether elec- 

 tric or galvanic, the fluid of heat, no less than the electric fluid, 

 may in both cases be concerned ; and it is yet to be shown, 

 that magnetic phaenomena are ever due to the unalloyed agency 

 of electricity. 



It is true that magnetism has been imparted, by discharges 

 of mechanical electricity, without any ostensible agency of ca- 

 loric ; but it is equally true, that magnetic movements have been 

 produced also, by the application of heat, unaccompanied by 

 any ostensible agency of the electric fluid ; and it seems as ra- 

 tional to suppose that caloric and electricity are associated in 

 the first instance as in the last. 



Those who consider electricity, varying in quantity and in- 

 tensity, as the common cause of electrical and galvanic ignition, 

 and of thermo-magnetic phaenomena, must suppose that this 

 principle and caloric are capable of a reciprocal action. In 

 the first case, caloric is evolved by electric action ; in the last, 

 electric currents are produced by calorific repulsion. Hence, 

 as action and reaction are equal and contrary, I deem it ra- 

 tional to suppose that in some cases the former, in other cases 



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