Electrodes in the Galvanic Arc of Light. 7 



character ; and it is just this series which has led to extraordi- 

 narily surprising results. Grove placed in the arc of light a 

 positive electrode of zinc over against a negative one of platinum, 

 and in his experiments took into consideration only the disinte- 

 gration which took place at the former. Now this zinc electrode 

 was of such dimensions, and the intensity of the current so regu- 

 lated, that the air should not occasion combustion of the massive 

 electrode, but only of the fine particles thrown off from it. The 

 air present was an isolated quantity ; and thus the amount of 

 zinc thrown off could be calculated from the oxygen consumed, 

 provided that all the disintegrated zinc, and this only, was oxi- 

 dized. Grove believed that now every thing had been approxi- 

 mately fitted to the conditions of this experiment, and concluded 

 from his results (which did not differ excessively from one an- 

 other) that the quantity of zinc disintegrated was equivalent to 

 that of the hydogen occurring in a simultaneously inserted vol- 

 tameter. 



The supposition herein expressed, of a surprising connexion 

 between disintegration and electrolysis, has not, to my know- 

 ledge, been followed up by other investigators. Indeed the diffi- 

 culty of satisfying, even in some measure, the conditions which 

 Grove sought to realize in his experiment is extraordinarily great ; 

 and this circumstance may very well have prevented the repetition 

 of the experiments, as it seems adapted not to permit too much 

 reliance on his data. . It must further be said that the idea which 

 Grove pursued in these experiments rested on erroneous assump- 

 tions. Namely, Grove thought that, if the electricity of the 

 current could only effect its passage between the electrodes in 

 combination with electrode-substance, then the quantity of elec- 

 tricity corresponding to a definite current-intensity would pro- 

 bably always determine the transport of a definite quantity of 

 substance of the electrodes. But, leaving altogether out of con- 

 sideration the decided improbability of the law of condition 

 herein contained, the electrode-substance thrown off and that 

 transported between the electrodes are quantitatively quite dif- 

 ferent. Van Breda's experiments have shown, and it will like- 

 wise be found in what follows, that only a portion of the disinte- 

 grated substance takes the path to the opposite electrode, while 

 another portion flies about in all directions. Grove's experi- 

 ments, however, are independent of this point of view ; for they 

 would indeed express the quantity, not of the transported, but 

 of the disintegrated zinc. 



Independently, therefore, of the reason which induced him to 

 make his experiment, it remains an open question whether there 

 does not exist a simple connexion between the quantity of active 

 electricity (that is, the intensity of the current) and the quantity 



