glS Experiments zoilh the Pile ef Folia. 



creafed furfaces of the plates in a galvanic apparatus> will be produdlive of proportionably 

 increafed power. 



Experiment 7. This experiment is not very difllmilar to that which you have related in . 

 your Journal, (page 185) in which you propofed to examine the aeriform matter, fe- 

 parately, that was produced by each of the bafes or poles of a galvanic apparatus. In this 

 experiment, an eleftric explofion was pafled through the gafes which iflued from the two 

 extremities of gold wire connedled with the oppofite bafes of the apparatus. 



The apparatus that was ufed was compofed of aoo plates of zinc, and 200 half crown 

 pieces, the difcs were of leather foaked in a folution of muriate of ammonia ; the extremi- 

 ties of two pieces of gold wire were introduced into a fmall glafs veflel filled with pure 

 water ; having an interval between them of ^ of an inch. This fmall veffel being com- 

 pletely immerged in a larger veflel of water, was inverted, and the projecting ends of the 

 gold wire attached to the bafes of the apparatus. 



The refult was, that gas iflued mofl: copioufly from both the extremities of the wire, 

 immerged in the water, and afcended to the upper part of the veflel, where it was colle£ted 

 in a large bubble, in the courfe' of the time the apparatus continued to aft, which was 

 about thirty hours. The wire connected with the zinc bafe was 3 feet 6 inches in length, 

 and the wire connefted with the filver bafe, about one foot. The former became much 

 tarniflied, gave out much air, but not fo rapidly, or for fo long a time, as the oppofite 

 wire. The part of the wire conneded with the filver bafe, that pafled through the water 

 in the outer veflel, alfo gave out much air, and became at lad incrufted with fome white 

 fubftance ; upon the bubbles which were conllantly afcending from this wire, a fmall quan- 

 tity of tinSure of turnfole was dropped, but it underwent no change of colour. No oxidfe, 

 or even a cloud, was produced in the water by either of the wires. 



The gas thus coUefted was decanted into a glafs tube, which was bent, the branches 

 being about four inches long, and two inches afunder ; the interior diameter was 0.3 inch, 

 and the gas occupied 1.5 inch in the curved part of this tube. The branches being then 

 placed in feparate veflels of water, and two metallic wires having been previoufly fixed in 

 this tube, having a fmall interval between their extremities at the part where the bubble 

 refted ; the difcharge of a fmall eleflricai jar was pafl"ed through thefe wires, and the ex- 

 plofion which took place in the bubWe, had fufilcient force to raife the tube, the weight of 

 which, with the wire and water it contained, was about three ounces. The bubble of 

 air was reduced to lefs than half its original dimenfions, either by a diminution of its quan- 

 tity, or of its elafticity. Many eledtrical explofions were then pafl"ed through the remain- 

 ing air, and alfo through it, when mixed with atmofpheric air, but without producing any 

 motion in the tube, or any other efl^eft. 



The tube was then removed, and a fmall quantity of a mixture of oxygenous, and hy- 

 drogenous gas, which happened to be ready prepared, was admitted into it, fo as to form a 

 bubble of the fame dimenfions as before ; and upon paffing the difcharge of the cledhrical 

 jar through it, the eiFeds were precifely the fame, as were obferved in the air extricated 

 from the gold wire, by the operation of the galvanic apparatus. 



Experiment 



