TOL. LXXXVII.] PHILOSOPHICAL TRANSACTIONS. 107 



§ 2. Experiments. — From my journal of the numerous experiments, made 

 during the course of nearly 2 years, I shall select those which will serve to explain 

 the nature of the process, and show the power of the plate electrical machines; 

 and I shall particularly relate those experiments which afforded the most useful re- 

 sults concerning the nature of the gaz obtained. 



]. With interrupted discharges. — Exper. a. About l6oo of these discharges, by 

 means of a 34 inch single plate electrical machine, in nearly 3 hours, produced, 

 from New River water taken from the cistern, and which had not been freed from 

 air by the air-pump or boding, a column of gaz ■§. of an inch in length and \ of 

 an inch wide. On passing through this gaz, between the 2 wires of the tube in 

 which it was produced, a single electric spark, its bulk was instantly diminished to 

 «.. In other experiments the bulk of gaz was only diminished to about \. And 

 the result was the same with distilled water. 



b. The experiment a being repeated several times, with distilled and New River 

 water, freed from air by the air-pump or long boiling, the quantity of gaz just 

 mentioned was obtained in about 4 hours. On passing an electric spark through 

 this gaz, in the situation above-mentioned, its bulk was instantly diminished, in 

 some cases -|-§-j and in others 44. 



c. l6(X) interrupted discharges, by means of a 32 inch plate machine, produced, 

 from New River water and distilled water freed from their air by the air-pump, a 

 column of gaz about \ of an inch in length, and 4- of an m °h m diameter, in the 

 space of 3 hours. It was reduced in bulk -f| by passing through it a single electric 

 spark. 



d. 500 revolutions of the 32 inch plate machine, in £of an hour, produced 600 

 interrupted discharges in river water, freed from air by the air-pump, by which a 

 column of gaz, 4- an inch in length and -^ of an inch in diameter, was obtained. 

 It was diminished, as usual, by an electric spark, -i-f- of its bulk. 



e. Nearly 4 days incessant labour, with the 32 inch plate machine, produced 

 only 56.5488 cubes of gaz, of -^ of an inch each; on account of the usual acci- 

 dents during the process. The air had been exhausted, by setting the water under 

 the receiver of the air-pump. 



f. It was found that 6000 interrupted discharges produced about 3 inches in 

 length of gaz, measured in a tube -^ of an inch in width, from water out of which 

 its air had been drawn by the air-pump. 



g. It appeared, from many experiments, that the same unboiled water, or water 

 from which the air had not been exhausted by the air-pump, which had repeatedly 

 yielded gaz by passing through it electric discharges, always left a residue of gaz, 

 which the electric spark did not diminish ; and this residue was in nearly the same 

 quantity, after 6 or 7 experiments, each of which afforded a column of gaz, 4- an 

 inch in length, and \ of an inch in diameter, as was left on passing the electric spark, 

 through the gaz, afforded by the 3d or 4th experiment. 



Hence it seems, that water is decompounded by the electric discharge, before the 



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