jS^ Gal-vav'ij'm, 



notice of them, however, {Iiall be brief, ns the projefted ex- 

 periments have not ail been gone through witli thofe varia- 

 tions of circumfiances which are intended to acconipany 

 them. Suffice it therefore to (late at this time, 



That, in concert with feveral gentlemen, zealous pronioters 

 of fciencc, and whofc names fliall be flatcd hereafter, a pile 

 was conftriiotcd confiftiug of thirty-fix pairs of plates of (ilver 

 and ainc, with difcs of flannel moiftcned with a loiution of 

 muriate of ammonia interpofed between the pairs: that each 

 plate was ten inches in diameter, or contained 78"54 fquare 

 inches ; and that, confequentiy, the whule furface of filver 

 in the pile, reckoning only one iide of each plate, was 2827'44 

 fquare inches, and that of zinc the lame. 



With this pile, at a meeting of a committee on the 39th 

 inft. (December), gold, filvcr, copper, tin, lead, and zinc, 

 were deflagrated with ahonilliing faciHtv. 



Gold burnt with a "very vivid white light, inclining a little 

 to blue. This experiment afforded an opportunity of deciding 

 a point left undetermined in one recorded in our lad Number, 

 by which gold was deflagrated without any rcfiduum being 

 perceived. On the prefcnt occafion, there was left on the 

 Tipper ]ilate a copious oxide of a deep brown colour, inclining 

 a little to purple. In the former experiment, the end-plate 

 of the trough to which the gold was appHed was vertical ; the 

 oxide could be but little in quantity, and, being nearly of the 

 colour of the mahogany on wliich it fell, accounts fuihciently 

 for its not having been perceived. 



Sil-ver gave a vivid green- coloured flame, extremely bril- 

 liant. The colour was fbmewhat like that of a pale emerald, 

 and the light more intenfe than that from the gold. Gave 

 an oxide inclining to black. 



Copper prefented phaenomena flmilar to thofe obferved in 

 deflagrating gold. 



Ler.d gave a light of a dilute olueifli purple, very vivid. 



Tin, a ligiit fimilar to that of the gold ; but it burnt with 

 leis energ\-, — perhaps owing to the leaves being thicker. 



Zinc gave a blueifli white flame, fringed at the moment 

 of contact with red. It was more difficult to be deflagrated 

 than any of the former, but the plates at the fame time were 

 much thicker. 



The oxides of thefe laft four metals were not examined. 



Some water having been poured upon the upper plate, fo 

 as to form a kind of little ftandino- pool, feveral of the metals 

 were prefented to the plate through this water, and were de- 

 flagrated, giving the fame coloured flame as when prefented 

 10 the bare plate. A vapour was fometimes perceivable in- 



Itautly 



