tj6 Addiiiomt RemarAt on Galvanic EUBricily. 



thefe platina points, I obtained gafes very nearly fimilar to thofe juft defcribed : but tlic 

 oxygen was not quite fo pure, as it often contains ^ or i of azote ; and when the mixed 

 gafes were exploded, as in the firft experiment with the gold wires, there was a refiduum 

 amounting to y of the whole, which was found to be a mixture of hydrogenous and azotic 

 gafes. It may be proper to obferve, that in all thofe cafes where the gafes were obtained 

 feparately, the volume of gas from the filver Gde was nearly three times that from the zinc 

 fide ; and that the former always cotitained a little oxygen, amounting to about ^ or tb. of 

 the whole *. 



The platina point, connefted with the zinc as well as the gold wire on the fame fide, 

 were after fome time evidently tarniftied ; and this effect was foon obferved when the 

 machine was in full aftion. 



In the following experiment I obtained a perfefl folution of gold : 



'After having precipitated magnefia and argill from their folutions in acids, by the in- 

 fluence of the wire from the filver fide, I was defirous to fee what effeft would be produced 

 on folutions of lime. For this purpofe the glafs tube was filled with a folution of the 

 muriate of lime which had been cryftallifed, and the gold wires applied in the ufual man- 

 ner. When the tube was placed in the circle of communication, little or no gas efcaped 

 from the filver wire, but a confiderable quantity began to afcend immediately from the 

 zinc one, and the fluid furrounding it aflumed a fine yellow colour, which was found to 

 proceed from a folution of the gold, the wire at the end of the procefs being much cor- 

 roded. After fome time gas was likewife difengaged from the filver wire, but there was 

 not the lead precipitation of lime ; when the wires were removed the fluid fmelled of aqua 

 regiai or the ox. muriatic acid. 



When platina points were employed inftead of the gold wires, the fmell of the nitro- 

 muriatic acid was alfo foon perceived, but no fenfible folution of the platina was ob- 

 fervable. 



This formation of the nitro-muriatic, or oxygenated muriatic acids, was not obferved 

 but where the perfedl metals gold and platina were employed } the reafon of which muft 

 be obvious. When the tube was filled with a folution of common fait inftead of the mu- 

 riate of lime, a nitro-muriatic acid was likewife produced. The eflFefts produced by the 

 gold or platina wires on the tinftures of Litmus and Brazil wood, were ftill more remark- 

 able than thofe defcribed in the former paper, more particularly on the litmus, which was 

 very quickly reddened. When the tube was filled with diftilled water only, and gold wires 

 employed; after the influence had pafled through for fome time (without confining the 

 gas) that portion of the fluid in contact with the filver wire being decanted, ftrongly red- 

 dened the tin£lurc of Brazil wood. This mode of making the experiment was preferred, 

 as it might be fuppofed that the hydrogen in itsnafcent ftate would unite with the colouring 

 matter of the Brazil wood, and produce the eflPe^t of an alkali. 



* Was this oxygen originally held in folotioabj the water? C. 



From 



