the Nature of the Gaz prccluced by pqffiiig EleSlrlc Difcharga through Water. 301 



of moiflure was imputed to "a bit of lime accidentally left in the tube which was burft by the 

 explofion, and difperfed through the tube ; or elfe the quantity of water produced was fo 

 fmall, comparatively with the refuluary gaz, that the water was.diirolved by it in the moment 

 of its compofition. For, fuppofing water to have been compounded, it could not amount 

 to the i-iooth part of a grain, and the refiduary gaz was at leail 20CO times this bulk. 



That a quantity of water can be compounded under the fame circumftances as in this ex- 

 periment, and be apparently diffolved in air, fo as to efcape obfervation, even with a lens, 

 was proved by pafTmg an elsiitric fpark through a mixture of hydrogen -and oxygen gaz, well 

 dried by Handing over lime. 



2. With complete or tminierriipifd Difchnrges. 

 - THE gaz obtain «1 by the firft defcribed kind of apparatus for the uninterrupted dif- 

 charges, p. 145, and Fig. 6, and 7, always left a refidue of at lead one-fourth of its bulk, 

 on paffing through it ths eleflric fpark ; even when water was ufed which had been freed 

 from air by boihng or the air pump. Nor will this refult appear furprifing, when it is con- 

 fulered how liable the water in this apparatus is to mix and abforb air during the experiment. 

 However, this method would have been extremely valuable, if the next other method had 

 not been difcovered ; for gaz may be obtained by it with fewer accidents, and much more, 

 rapidly, than with the interrupted dlfcharges The apparatus is alfo much more eafily fitted 

 up, and is more fimple. But I think it unneceflary to particularly relate any experiments, 

 as they afforded the fame refults as thofe already defcribed, and as thofe next to be related. 



The following experiments were made with the apparatus defcribed p. 146, and Ihewn 

 by Fig. 8, 9, and 10: 



Experiment I. At oh. 40' P. M. began to produce difcharges with a double plate twenty- 

 four inch machine, in water taken from the ciftern ; and at 12 Ii. 6' P. M. of the fame day 

 there had been written down 10200 difcharges, each of which occafioned air to afcend from 

 the bottom of the wire and brafs cup. The quantity of air obtained was now apparently 

 about one-fourth of a cubical inch, and it occupied nearly half of the tube, the water in 

 which was by this time very muddy. 



After Handing till the day following at noon, when the procefs was again commenced, it 

 did not appear that any of the gaz had been abforbed by the water over which it flood. 



At 2 h. 35' P. M. began to produce difcharges, a:id at 8 h. I'.M. had palled 6636; 

 which, together with thofe of the preceding day, amounted to 16,836. The tube was 

 now 5-Eths full of gaz, and there feemed to be almoft half a cubical inch ; for it was ob- 

 ferved that the gaz was this day yielded at double the rate it had been the day before. This 

 ■was accounted for from the diminilhed preflure upon the eleflric fire, by the tube con- 

 taining gaz inftead of water. 



At this time, namely at 8 h. P. M. I was furprifed on the paffmg of a difchnrge by a vivid 

 illumination of tiic whole tube, and a violent commotion within it, with, at the fame time, 

 the rufliing up of water, inftantly to occupy rather more than j-8ths of the fpacc which had 

 been occupied by gaz. 



The refidue of gaz was not diminiflied further by an clecflric fpark ; and to the tefl of 

 nitrous gaz it appeared to be rather worfc than atmofphcrical air, as it confided of rather 

 kfs than one part of oxygen, and three parts of nitrogen or azotic gaz. 



3 It 



