136 'Ml'. M. Donovan on the supposed Identity of the Agent 



to his law*. The essence of a law of nature is its universality; 

 if there be an exception, the alleged law is not a constituent 

 ordination in the organization of the universe. Should we not 

 confine the application of this law, if it be really a law, to the 

 operations of the voltaic agent, whatever it may be, and with- 

 di'aw the decomposition of water by frictional electricity alto- 

 gether from its comprehension, claiming its refractory comport- 

 ment as a proof of diflference rather than of identity ? 



The decomposition of watei-, accompanied by voltaic arrange- 

 ment of the elements which the hydro-electric machine is known 

 to effect, offers no objection to the foregoing reasoning ; the fact 

 only proves, what is nowhere denied in this essay, that in all 

 electricity there is an admixture of the constituent element which 

 imparts to voltaic phsenomena their characteristic chemical powers. 

 Nay, the necessity of such an enormous quantity and intensity 

 of frictional electricity for the decomposition of water is in itself 

 a presumption that the real agent is not the electricity proper, 

 but some other constituent, of which the former is but the 

 vehicle. If the electric fluid, amongst its other elementary con- 

 stituents, contain even the most minute portion of that chemical 

 agent which in voltaic phsenomena produces the chief part, a 

 continued torrent of sparks ought to produce just the small evi- 

 dences of chemical action which we observe. Perhaps the small 

 degree of chemical action which large quantities of frictional 

 electricity exercise, affords us the best measure of the real de- 

 composing agent present. Instances will be given in a subse- 

 quent part of this essay, where the ratio of the chemical consti- 

 tuent appears to predominate over what I have called the elec- 

 tricity proper, as much as, in frictional electricity, the latter does 

 over the former. 



There is a point of view in which the relation of electricity to 

 affinity must be considered with the object of questioning whether 

 decompositions effected either by ordinary or voltaic electricity 

 are explicable by, and compatible with the doctrine of electro- 

 chemical equivalents, viz. that " the equivalent weights of bodies 

 are simply those quantities of them which contain equal quan- 

 tities of electricity, or have naturally equal electric powers; 

 it being electricity which determines the equivalent number, 

 because it determines the combining force. Or if we adopt the 

 atomic theory or phraseology, then the atoms of bodies which 

 are equivalents to each other in their ordinary chemical action 

 have equal quantities of electricity naturally associated with 

 themf." Hence we learn, that, according to this view, the atoms 

 of matter are all endued with equal quantities of electricity, 



* Researches, pai-. 329. t Il>id. par. 869. , , 



