Experiments in Galvanic WeSrhtty. 341 



\sas done by weighing the bottles, it was found that the 

 quantities of wfiter dil'placed by the gafes were, refpedively, 

 5-3 grains by the gas from the zinc fide, and 142 grains by 

 the gas from the fiJver fide ; lo ihat the whole volume of gas 

 was 1.17 cubic inches, or near an inch and a quarter. Thtlo 

 are nearly the proportions in bulk of what are italed to be 

 the component parts of water. The gas from the zinc fide 

 being tried with one mealure of nitrous gas, contracted to 

 1.25, and did not contract more by the addition of another 

 nieafivre; the gas from the filver lide, by the fame treatment, 

 contrafted to \.6, The air of the room, on trial, contracted 

 to 1.28. From the fmallnefs of the quantity, no attempt 

 was made lo detonate the air from the zinc fide ; but a por- 

 tion of that from the filver fide, being mixed with one-third 

 of atroofpheric air, gave a loud detonation. 



'' Upon the above it may be remarked, that it does not 

 feem probable that oxygen was afforded by both wires, but that 

 they were mixed by the circumftances of the experiment.'* 



Mr. Cruickfliank, of Woolwich, alfo made fome interefl:- 

 jng experiments on this fubjecl. He employed plates of 

 zinc and fiber about 1.6 inches fquare; and the number of 

 each varied from 40 to too, according to the power required. 

 He ufed filver wire both from the zinc and filver plate in his 

 firft experiments ; but to dillinguifli the ends of the pile, that 

 wire only is called the filver wire, which was conneded with 

 the filver plate ; the Qther wire he calls (to fave circumlocu- 

 tion) the zinc wire. Thefe wires were pafled through corks, 

 fitted into a glafs tube filled with water, and one of the corks 

 made perfectlv tight by means of cement, " Thp tube was 

 then placed upright in a cup containing water, with the un- 

 cemcnted end downwards. As fooa as the communication 

 was made between tbe e-xtremitics of the pile by the wires, 

 a quantity of fmall air bubbles began to afcend from the end 

 of the w ire connected with the filver, as obferved by Meffr?, 

 Nichoifon and Carlifle ; but a while cloud at the fame time 

 made its appearaoce at the pne proccrding from the zinc, or 

 the zinc wire. This cjoud gradually incrcafed, arid afl'umed 

 a darker colour, and at la(i it became purple, or even black. 

 A very few air bubbles w^re likewife colleded upon and 



afccndcd 



