Exptriments with the Galvame Apparatut, tjf 



furcs remained. Hence the 33 meafures of gas evidently contained more than 31 mea- 

 fures of oxygen. The 6» meafures in the other tube, gave with nitrous gas a diminutioa 

 but barely perceptible, and fired after the abforprion of the nitrous gas by the ele£lrie 

 fpark, with 60 meafures of oxygA, left a refiduum nearly equal to 36 meafures } hence 

 the gas was hydrogen almoft pure. 



c. There was every reafon to fuppofe, that the flight diminution produced by the mix- 

 ture of the hydrogen with nitrous gas in the laft experiment, as well as the refidual gas of 

 the oxygen, were owing to common air held in folution by the didilled water, and given 

 out from it during the procefs. To afcertain if the gafes could be obtained perft£lly pure, 

 when water deprived of its loofely combined air by boiling was employed. The two tubes ' 

 were filled with water that had been boiled for more ttan eight hours, and that was yet fo 

 hot as to be painful to the fingers; the glaffes were filled with water of the fame kind, and 

 the procefs conduced as before ; the tubes being fufFered to cool before the communica- 

 tion was made, gas was given out very rapidly from the water connefted with the filver ; 

 but very flowly from that connefted with the zinc. During the whole of the procefs, no 

 globules of air formed on the fides of the tubes, as in the laft experiment. In five hours 

 the tube conne£led with the filver contained 56 grain meafures of gas. That connected 

 with the zinc contained only 14 meafures. The 56 meafures gave no diminution with 

 nitrous gas, and appeared by the teft of detonation, to be pure hydrogen. The 14 mea- 

 fures tried by the tefts mentioned in the laft experiment, appeared to be oxygen, mingled 

 ■with no perceptible quantity of other gas. In this experiment, as in the laft, the gold 

 wires were not apparently adted upon, nor was their color in the flighteft degree altered i, 

 the deficient proportion of oxygen, there was every reafon to believe, was owing to the 

 abforption of that gas in the nafcent ftate by the boiled water. Boiled water was now ex- 

 pofed to, and agitated In oxygen over mercury, till It was judged to be faturated with that 

 gas. The tube connefted with the zinc was filled with this water; the other tube was 

 -filled with common boiled water. The galvanic procefs was continued feven hours. In 



this time the water connefted with the zinc had given out 27 grain meafures of oxygen, 

 apparently pure ; from the water conne£led with the filver, 57 meafures of hydrogen had 

 been extricated. 



d. Having thus afcertained that oxygen and hydrogen, nearly in the proportions required 

 to form water, could be feparately produced from quantities of water, having no commu- 

 nication with each other, except by means of the dry metallic condudlors and mufcular 

 fibre. I next endeavoured to afcertain, if the conta£t of the metallic wires, with the 

 metallic plates of the apparatus, were cfiential to the efFeft.. The conducing ends, /. e. 

 the filver and zinc, were made to communicate with two glaflfes of water, by means of 

 two unconnefted pieces of mufcular fibre. A piece of filver wire was made the medium 

 of connexion between the glafles. Immediately after the connexion, I was furprized by 

 feeing that end of the wire in the water communicating with the filver calcining ;. whilft 

 gas was given out from that part of it in the vefibl cooununicating with the zinc }.*a8 was- 



the: 

 3 



