Mr. Grove on the Gas Voltaic Batter?/. 4*27 



stinct, if not the only conceptions of the mind, with regard to 

 natural phaenomena, and when we try to comprehend or ex- 

 plain affections of matter which are not obviously modes of 

 motion, we hypothetically or theoretically reduce them to it: 

 the senses perceive the different effects of sound, light, heat, 

 electricity, &c, but the mind appears capable of distinctly 

 conceiving them only as modes of motion. Does not this 

 supply an argument that all physical agencies are reducible to 

 these elements of mental conception ? Or are we to look for 

 new powers of mind, in other words, will greater familiarity 

 with phaenomena, at present recondite, enable the mind more 

 clearly to comprehend them, and avoid the necessity of refer- 

 ring them theoretically to more familiar, and apparently more 

 simple phaenomena? To pursue this curious inquiry would 

 involve me in a discussion foreign to the object of this paper 

 and to the general character of contributions to the Royal 

 Society, but the question arises so immediately out of the sub- 

 ject, and is so necessary to explain my own view, that I trust 

 this brief statement of it will be considered sufficiently perti- 

 nent. It touches upon that interesting, scarce definable 

 boundary, where physical merges into metaphysical science. 



There are one or two other theoretical points as to which 

 the gas battery offers ground of interesting speculation ; the 

 contact theory is one. If myfaotion of that theory be correct, 

 I am at a loss to know how the action of this battery will be 

 found consistent with it. If, indeed, the contact theory assume 

 contact as the efficient cause of voltaic action, but admit that 

 this can only be circulated by chemical action, I see little dif- 

 ference, save in the mere hypothetical expression, between the 

 contact and chemical theories; any conclusion which would 

 flow from the one would likewise bededucible from the other; 

 there is no sequence of time in the phaenomena, the contact or 

 completion of the circuit and the electrolytical action are syn- 

 chronous. If this be the view of contact theorists, the rival 

 theories are mere disputes about terms. If, however, the con- 

 tact theory connects with the term contact an idea of force 

 which does or may produce a voltaic current independently 

 of chemical action, a force without consumption, I cannot but 

 regard it as inconsistent with the whole tenor of voltaic facts 

 and general experience. 



Another point of theory suggested by the gas battery, is the 

 relation of latent heat in the different cells of the battery and 

 voltameter. According to our received theory of caloric, 

 oxygen and hydrogen cannot assume the gaseous from the 

 liquid state without rendering sensible heat latent. Now, as 

 in the gas battery the gases evolved from the liquid in the 



