j88 Ntw EUHricd or Galvanic Apparatus. 



I fliall not give any particular account of the apparatus employed, being a pile, and not 

 differing materially from that in ufe. I Ihall only jufl; obferve, that it confifted of plates 

 of zinc and filver, of about i .6 inches fquare, and that the number of each employed in 

 the following experiments varied from 40 to 100, according to the power required. 



I found that a folution of the muriate of ammonia anfwered better for moiftening the 

 interpofed papers than common water. 



When the machine was in full a£tion, fparks, which were perfeftly vifible in the day 

 time, could be taken at pleafure, by making a communication in the ufual way between the 

 extremities of the pile, and a fmall report or fnap could be heard ; the fiiocfc given at that 

 time was very ftrong, and a gold leaf ele£trometer, placed in the circle of communication,, 

 was very fenfibly affected : thefe circumftances, fome of which I believe have been already 

 afcertained by Meflrs. Nicholfon and Carlifle, (hew the ftrong refemblance of this in- 

 fluence to eleftricity. Thefe gentlemen have likewife difcovered that galvanifm de- 

 compofes water with much greater facility than ele6lricity, but with phenomena fome- 

 what difFerent. 



Experiment t. — A quantity of common water was introduced into a glafs tube, being 

 confined at each end by corks, but perfe£tly at one by a cement of rofin and bees'-wax : 

 pieces of filver wire were pafled through the corks, and brought within an inch of each 

 other in the fluid, their other extremities being at the fame time conue£ted with thefe of the 

 machine or pile, one with the lower zinc plate, and the other with the upper filver platc.^ 

 In future, to avoid circumlocution, I fiiall call the wire attached to the filver plate, the 

 filver wire, and the other the zinc wire. The tube was then placed upright in a cup con- 

 taining water, with the uncemented end downwards. As foon as the communication was 

 made between the extremities of the pile by tlie wires, a quantity of fmall air bubbles began 

 to afcend from the end of the wire connecfted with the filver, as obferved by Meflrs. 

 Nicholfon and Carlifle ; but a white cloud at the fame time made its appearance at the one 

 proceeding from the zinc, or the zinc wire. This cloud gradually increafed, and aflunied 

 a darker colour, and at laft it became purple, or even black. A very few air bubbles 

 were likewife colledted upon and afcended from this wire, but when the machine was in. 

 full force, a confiderable ftream could be obferved. 



The gas was colle£led, and found to be a mixture of hydrogene and oxygenc, in the 

 proportion of three parts of the former to one of the latter. No great dependence, how- 

 ever, was placed upon this in point of accuracy. The zinc wire was found to be much 

 corroded, and looked as if a confiderable portion of it had been diflblved. As the cloud 

 which was formed around this wire became purple on espofure to the light, I fufpeftedi 

 It might be luna cornea, or muriate of filver proceeding from the filver, which had been 

 fomehow diflblved, and afterwards precipitated in this ft:ate, by the muriatic falts in ;h'e 

 common water. This led to the following experiments : 



Experimettt 2. The glafs tube was now filled with difi:iHed water, to which a little tinc- 

 ture of litmus was added, when the communication was made by the wires as in the for- 



Kier. 



