(t6 Experimtnls with a New EkSrical or Galvanic Apparatvs. 



bles were extricated from all-parts of the water, and adhered to the whole internal furface 

 of the veflels. The procefs was continued for thirteen hours, after which the wires 

 were difengaged, and the gafes decanted into feparate bottles. On meafuring the 

 <juantlties, which was done by weighing the bottles, it was found, that the quantities of 

 water difplaced by the gafes, were refpedively, 72 grains by the gas from the zinc fide, 

 and 142 grains by the gas from the filver fide ; fo that the whole voliwne of gas was 1.17 

 cubic inches, or near an inch and a quarter, Thefc are nearly the proportions in, bulk, of 

 what are ftated to be the component parts of water. The gas from the zinc fide, being 

 tried with one meafure of nitrous gas, contradled to 1.25, and did not contraft more by the 

 addition of another meafure ; the gas from the filver fide by the fame treatment contrafted 

 to 1.6. The air of the room, on trial, contraded to 1.28. From the fmallnefs of the quan- 

 tity no attempt was made to detonate the air from the zinc fide, but a portion of that 

 from the filver fide, being mixed with one third of atmofpheric air, gave a loud detonation. 

 Upon the above it may be remarked, that it it does not feem probsble that oxigen was 

 aflforded by both wires, but that they were mixed by the circumftances of the experiment. 

 For the gafes being extricated in extremely minute bubbles beneath the inverted veflels, 

 caufed a flow afcending current confifting of water mixed with thofe bubbles, many of 

 which were undoubtedly too fmall to be difcerned. This afcending current gave out as 

 much of Its gas at the top of the velFel, as had time to conglomerate ; but the extremely 

 minute bubbles would return in the defcending current, and be repeatedly carried, up 

 before this effect could take place. Such a continual circulation, or ftream, the lower part 

 of which pafled down into the faucer, muft at length have occafioned the whole mafs of 

 fluid to become replete with thefe minute bubbles, which would break at the open furface, and 

 be loft, or attacl; themfelves to the fides of the veflel, as was feen to be the cafe. "What 

 proportion may have thus difappeared is uncertain ; but it is highly probable, that one 

 confequence of the imperfections of our apparatus, was to occafion both the inverted vef- 

 fels to become receptacles for the gafes from both wires indifcriminately ; though moll 

 plentifully in each, from the wire immediately beneath its mouth. If this reafoning may 

 be admitted for the prefent, till the experiment is repeated in clofed veflels. It will be fair 

 to reckon the whole diminution on both the quantities. The whole diminution was 1.15, 

 whence it would follow, that the purity of the oxigen eftimated in Prieftley's manner, 

 would be esprefltd by the number O.85. 



On account of the length of this communication, I fhall at prefent forbear to enter into 

 any confideratlons of theory, but fhall conclude with a concife mention of the effe£ts of a 

 pile of one hundred half crowns, and a chemical incident, which appears to be the moft 

 remarkable of thofe which I have yet obferved. 



The pile was fet up with pieces of green woollen cloth foaked in fait water. It gave 

 fcvcre (hocks, which were felt as high as the Ihoulders. The tranfition was much lefs 

 forcible dirough a number of perfons, but it was very perceptible through nine. The 



fpark 

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