the Voltaic disruptive Discharge. 481 



of electricity, and thrown into a state of intense chemical or 

 mechanical action ? Matter is undoubtedly detached during 

 the disruptive discharge, and this discharge takes its tone 

 and colour from the matter employed. Now as this separa- 

 tion is effected by electricity, electricity must convey with it 

 either the identical quantity of matter with which it is asso- 

 ciated, or more or less; more it can hardly convey, and if less, 

 some portion of electricity must pass in an insulated state, 

 or unassociated with matter, and some with it. This seemed 

 a highly improbable effect, and these considerations, imme- 

 diately deducible from Faraday's researches, led me to 

 suppose that the third alternative was most probably the 

 true one, and consequently that the quantity of matter de- 

 tached by the voltaic disruptive discharge was definite for 

 a definite current, or bore a direct equivalent relation to the 

 quantity electrolyzed in the liquid portions of the same cir- 

 cuit. The difficulties of testing this view by the weight lost, 

 being insuperable without incurring an unjustifiable expense, 

 led me to have recourse to Experiment 5. Zinc having only 

 one oxide which sublimes when deflagrated in air by voltaic 

 electricity, it should follow that if the particles of zinc de- 

 tached were the equivalents of the matter electrolyzed in the 

 same circuit, the quantity of oxygen absorbed by these parti- 

 cles would be exactly equal to that evolved in a voltameter 

 placed in the circuit. The experiment presented more dif- 

 ficulties than I had at first anticipated : if the intensity of the 

 battery was high, I frequently observed the metal, from the 

 heat it had acquired, burn independently of the discharge; 

 while if the intensity were lowered, the dischai'ge could not be 

 kept up without frequent contacts which gave a gush of gas 

 to the voltameter. The following means afforded me the 

 must uniform results. Between a positive electrode of distilled 

 zinc of such size as to prevent by the cooling effect of its 

 mass an independent combustion, and a negative electrode of 

 platina, a moderated discharge was taken in a graduated vessel 

 filled with atmospheric air : an average of 40 experiments gave 

 me 1-17 to 1"00 as the inverse ratio between the volume of 

 oxygen evolved in the voltameter, and that absorbed by the 

 deflagration, and in several of these experiments the volumes 

 were exactly equal. The nature of the experiment defied 

 perfect accuracy, but considering a fevi^ unavoidable contacts, 

 it appears to me to afford strong ground for presumption if 

 wot for conviction, that the separation of matter in the voltaic 

 arc ii definite for a definite quantity of electricity, and that 

 the all-mjportant law of Faraday is capable of much exten- 

 sion. Uniting Wiltk vi«'v with the pvpprimpnta of Faraday 

 Phil Mag. S. 3. Vol. 16. No. 105. June 1840. 2 K 



