and its Theory, 55 



that I need, as to my facts and views on this subject, shrink from 

 an appeal to the judgments of the competent readers of this emi- 

 nently philosophical publication. 



The gas battery of Mr. Grove, as most readers are aware, con- 

 sists of a series of cells, each containing two tubes of glass sealed 

 at one end, and in which are inserted by fusion long narrow pla- 

 tinum plates and attaching wires, the plates reaching a little 

 below the bottom of the tubes. These tubes are partly immersed 

 by means of a ground collar into a square three-necked Woulfe's 

 bottle, the centre hole between the tube-holes being stoppered. 

 The tubes are usually two-thirds filled, the one with hydrogen 

 two volumes, the other with oxygen one volume, the bottle and 

 remaining part of the tube holding the usual dilute sulphuric 

 acid to complete the circuit. The platinum is, in order to pro- 

 mote contact with the respective gases and the liquid, covered 

 with platinum-black ; metallic contact between the tubes or to 

 the galvanometer is made by mercury cups attached to the pla- 

 tinum wires. I have been thus particular in describing the form 

 of cell, because my case rests upon the results obtained by a pair 

 which I have constructed and charged in a similar manner in all 

 apparent essentials, with only one important difference (as the 

 fact turns out), namely, omission of the platinum-black. In 

 my pair I simply use plain clean platinum, first burnished with 

 agate and then further cleansed with tripoli, ammonia, and spirits 

 of wine ; so that it is chemically and electrically clean, as expe- 

 riment easily shows. Thus far premised, and all being arranged, I 

 proceed to experiment with each instrument. With Mr. Grove's 

 pair, which I will call A, I get of course a powerful deflection 

 with an ordinary good galvanometer ; with the plain platinum 

 pair B, none. The A-tubes left in metallic contact for some time 

 show a tolerably rapid disappearance of the gases. The B-tubes 

 left in contact for the same time, no sensible disappearance. But, 

 more than this, the A-tubes left without voltaic metallic contact 

 show a rather rapid rise of fluid, especially in the hydrogen one. 

 The B-tubes in a parallel experiment, in which the time is not 

 too long, show no alteration of level, but after several days a little 

 hydrogen has disappeared : this I attribute to the difficulty of 

 burnishing the edges of the foil used. 



The whole of the facts needed for our purpose are now before 

 us. There is, as might have been foreseen, evident chemical union 

 of free gaseous particles, obtained by diffusion, in the tube contain- 

 ing platinum-black, and none sensibly in the plain-platinum 

 tube ; and since in the one case there is a current following me- 

 tallic contact, and in the other none, it follows, I humbly submit, 

 that antecedent static electric action, produced here, I admit, by 

 chemical action (but of direct combination, and not of indirect 



