89^ Olfervalions of Galvanic Proctfes. 



its eflentiality. The compound of concentrated fulphuric acid and oxigenated muriatic 

 acid * (which may be formed by introducing oxigenated muriate of pot-afli into fulphuric 

 acid, or by palling oxigenated muriatic acid gas through it), flowly oxidates both zinc and 

 filver, the oxigenated marine acid being cdecompofed. I expedled that it would produce 

 ftrong galvanic effefts when made the communicating medium of the cells of a pile; but in 

 this I Was difappointed ; a feries of twenty pairs connefted by it produced hardly any 

 fenfible a<ftion. 



5. If any perfon wiflics to repeat the experiments in vacuo juft detailed, great caution 

 muft be obferved with regard to the quantities of acids introduced into the cells. Two or 

 three drops in each will be fufficient, particularly if it has been previouily a little 

 moiftened. When larger portions are employed, the efFcrvefcence highly incrcafed by the 

 removal of atmofpheric prelTure will be often fufficient to moiften the edges of the cells, 

 and to make a communication betweem them. In confequence of the ufe of too much 

 acid, I have made many unfuccefsful experiments. 



The water ufed in vacuo for connecting the wires fliould be always previoufly deprived 

 of loofe air by long ebullition, or otherwife the difengagemcnt of that fubftance from it 

 will much difturb the refults, 



II. 



Obfervations gained from minute InfpeElion of Galvanic Prove Jer. 



I. Whenever the galvanic circuit, palTing through the pile with wires, is broken by 

 means of water, oxygen is uniformly produced at the zinc metallic point, and hydrogen 

 at the filver metallic point. This is (hewn from many experiments in Mr. Nicholfon's Phi- 

 lofophical Journal. Confidering analogies, an interefting queflion occurs. Do not the 

 fame phenomena take place in every part of the feries .' i. e. is not oxygen fixed on every 

 plate of zinc, and hydrogen produced on every plate of filver, at the points of their con- 

 taft with the water of the cloths ? With the hopes of gaining a folution of this queftion, 

 I conftrudted a feries of twenty glaffes with fpring water, containing plates of filver and 

 zinc connefted by brafs wire, in the mode pointed out by Volta. This feries gave feeble 

 fhocks, and a filver wire connefted with it produced the ufual appearances in water. 

 Oxygen was fixed upon that part of the wire in the glafs containing the laft filver plate, 

 and hydrogen was liberated from that part of it in the glafs containing the laft 

 zinc plate. 



The feries was made analogous in all its parts, the end glafles being connefted by a pair 

 of plates, fo that every glafs contained a filver plate and a zinc plate. On minutely in- 

 fpefting the glafles immediately after, no particular phenomena could be perceived. But 

 after occafional attention to the proccfs for many hours, I obferved the zinc plates 



• I accidentally difcovered this combination in July, 1799. Some of its properties are very peculiar. 

 More intereliiug enquiries hare hitherto prevented me from minutely examining them. 



4 beginning 



