Experiments with the Galvanic Apparatus. 279 



Surprized at tliefe refults, which proved that no decompofition of pot-afli had taken 

 place, and that that fubftance in this mode of operating, only enabled the galvanic influ- 

 ence to extricate oxygen and hydrogen more rapidly from water, I was induced to operate 

 Hpon this fubftance in the way of direft communication. Two gold wires were pafled 

 through holes in the fide of a fmall glafs tube clofed at one end, and cemented fo as to be 

 diftant about the eighth of an inch. This tube was filled with folution of pot-a(h, and 

 inverted in glafs filled with the fame fubftance; the gold wires were made to communicate 

 with the ends of the pile. Gas was produced rapidly from both wires, but moft from the 

 filver wire -, the gold was not a£l:ed upon, and no depofition took place. When near a 

 quarter of a cubic inch of gas had been collected, it was transferred to a detonating tube, 

 and fired by the eledlric (hock over mercury, it gave a vivid inflammation, and left a 

 globule of air not equal to -j-V of the whole quantity. 



b. Solutions of cauftic ammoniac were expofcd to the galvanic influence in the two 

 tubes with gold wire, and connected by mufcular fibre. Gas was given out very flowly 

 in the tube connefted with the zinc, and the gold wire was evidently a£Ved upon, being 

 in fome parts corroded, and in other parts covered by a yellow depofit. In the tube con- 

 nefted with the filver, gas was given out more rapidly, and the gold was not altered in 

 appearance. In five hours the gas in the zinc tube was equal to 5 meafures, and proved 

 to be a mixture of nearly 3 oxygen, and 2 of nitrogen. The gas in the filver tube mea- 

 fured 31 grains, and appeared to be hydrogen, mingled with a minute quantity of nitrogen. 

 I repeated this experiment feveral times, to afcertain if after the folution of ammonia had 

 been long galvanized, the proportion between the gafes would be different. The gas 

 given out in the zinc tube was always to that in the filver tube nearly as i to 6, but the quan- 

 tity of oxygen appeared to increafe towards the end of the procefs. A quantity of folu- 

 tion of ammoniac, the fame as that ufed in the experiment expofed to heat in a mode de- 

 fcribcd \n Reft arch. Chem, ^ Phil, page 241, readily produced ^ of its bulk of unab- 

 forbable gas, which gave no diminution with nitrous gas, and appeared to be nitrogen.. 

 In every experiment yellow depofit was formed upon the gold in the zinc tube ; muriatic 

 acid poured upon fome of this yellow depofit flowly diflblved it, a little nitrogen being 

 given out during the folution. 



When a folution of cauftic ammoniac was expofed in the filver tube, and water in the 

 zinc tube, the gold wires were not perceptibly altered, and oxygen was given out in the 

 zinc tube and hydrogen in the filver tube, nearly in the proportions required to produce 

 water. When on the contrary water was connefled with the filver, and folution of am- 

 moniac with the zinc, hydrogen was produced from the water; the zinc gold wire was 

 corroded, and the mixture of oxygen and nitrogen to the hydrogen, as fix to one, (one 

 to fix ?) was produced as before. 



c. Concentrated fulphuric acid was galvanifed in the double tubes connected by muf* 

 cular fibre. The gold wire in the zinc tube was not diflTolved or corroded, and in a great 

 length of time 41 meafures of gas, which proved to be pure oxygen, were given out from 



4 it. 



