ON GALVANIC BATTERIES. J£ 



tains some facts which had not before appeared in print* observed by 

 and, consequently, were not backed by any specified au.* Mr * Sylvester, 

 thority. As the authenticity of therri might on this account 

 be questioned^ I beg to state, through the medium of your 

 Journal, that they were developed during a series of expe- 

 riments, iu which I was engaged several years ago, and 

 have been very frequently exhibited in my lectures upon 

 the subject, la my present communication, I shall take 

 the opportunity of recording one or two others, which did 

 not occur to me at the time 1 wrote that article, and which, 

 in a practical point of view, may not be deemed altogether 

 unimportant. 



About three years since, I devoted some time to the in- Battery with ' 



vestigation of the subject of galvanic batteries, and have metals «e- 

 . J ii • i , , parated by glass 



now in my possession one made at that period ; the cells of plates 



which are formed with glass plates, so as to allow the plates 

 of metal to be taken out and put in at pleasure. A similar 

 plan is at present in use, and these batteries are said to pos* - 

 sess the advantage of exposing double the surface of the 

 common ones. I did not find this the case by any means, 

 in my inquiry into the subject, and it was under this idea, 

 that I did not persevere in the discovery. The reason I give h as not double 

 for these batteries not having double power is, that two of the power of 

 the surfaces of each pair of plates are not contiguous. I e common 

 have since that time obviated this evil, and hope very soon 

 to give yon an account of a battery, considerably more im- 

 proved in construction. A fact, which furnishes a useful Fact apparent- 

 lesson upon this point, is the following: let two wine glasses 'y proving, that 

 be nearly filled with dilute muriatic acid ; and afterward LcVshould he 

 immerse in them an arc composed of a piece of zinc and a greater- than 

 piece of copper wire; the zinc being in one vessel, and the 

 copper in the other. Tf another arc, formed of similar 

 wires, be then plunged into the glasses, in a reversed order, 

 observing that the arcs do not touch each other, a very rapid 

 decomposition will take place, and hidrogen will be evolved 

 from each of the copper wires. Let one of the above arcs 

 be now removed, and the connexion be made by means of 

 an arc consisting of one metal only; the copper wire of the 

 compound arc will be seen still to afford bubbles of hidrogen, 

 but in much less quantity. Instead of this simple arc, em- 



. ploy 



