i3l24 Chemical ^ffeBs of Galvanic EkBrlciiy. 



1. To the hiftory of the phenomena, attending the decompofitlon of water by this ntvr 

 influence, which have been already accurately defcribed by yourfelf, and by Meflrs. 

 Carlifle and Cruickfliank, I have little to add. If the water be confined by mercury, in a 

 tube with a conduQor fealcd hermetically into one end, a produftion of gas only takes 

 place, when the conductor communicates with the filver fide of the apparatus ; and if the 

 order be inverted, i. e. if the mercury be conne£l:ed with the filver end, and the conduftor 

 nt the fealed extremity of the tube with the zinc end, of the pile, no gas whatever is pro- 

 duced, though the agitation of the furface of the mercury in the tube Ihews that the in- 

 fluence is (till tranfmitted. On paffing up a wire of any metal through the quickfilver, fo 

 that its extremity may rife into the water, gas then begins to afcend copioufly from the 

 lower wire. Does not this fliew, that pointed bodies are more efFe£lual in decompofing 

 water than bodies with rounded furfaces ? 



It may be worth while to pbferve, that the change of the colour of litmus from blue to 

 red, occurs in diftilled water, even after long boiling. From Dr, Pearfon's experiments*, 

 however, it appears that air is feparated by e!e£lric (hocks from water, which has been 

 expofed under a receiver, exhaufted by a powerful air pump. 



2. Concentrated fulphuric acid was fubmitted to this influence, in a glafs tube, fur- 

 niflied with two platina condu£tors, the open end of the tube being immerfed in a cupful 

 of the fame acid. Gas was produced in great plenty, one half of which was abforbed by 

 fulphuret of potafh. The remainder was hydrogenous gas, from the decompofitlon of 

 ■water, which even the ftrongefl fulphuric acid neceflarily contains. But as the oxygenous 

 gas was fufficient to have faturated twice the quantity of hydrogen gas evolved, one half of 

 the former muft have had apother origin than water, and may he afcribed to the decom- 

 pofiition of the acid. Indeed, during the pafl'age of the ele£lricity, a white cloud was ob- 

 ferved to furround the wire from which the gas afcended, and which was probably 

 difoxygenated fulphur. 



3. Perfeftly pure and colourlefs nitric acid was rapidly decompofed in a fimilar ap- 

 paratus. The acid affumed a ftraw colour, and gas was obtained, confifting of oxygenous 

 and azotic gafes, in the proportion of 530 of the former to 151 of the latter. 



4. From liquid muriatic acid, 424 parts of gas were evolved, of which 144 were 

 oxygenous, and 280 hydrogenous. Thefe gafes had, doubtlefs, their origin from the de- 

 compofition of water. The quantity of the acid being confiderable, in proportion to the 

 gafes produced, it did not exhibit the marks of having become oxygenated during the 

 experiment. 



5. A tube was prepared with platina condudors, covered with wax, and being filled 

 with a faturated folution of oxygenated muriatic acid in water, the circuit was completed 

 through it, between the two ends of the pile. The gas evolved was a mixture of oxygenous 



* Phil. Tranf, 1797, or this Journal, vol. I, 



and 



