r 



Mr. R. Phillips ow /^ie Jfa^ne^zm 0/ Pew^g^ Coils ^ 2^ 



much positive electricity would at these times pass to the elec- 

 trometer as was apt to destroy the gold-leaf. 



176. The foregoing experiment (174.) is decisive in showing 

 that the increase of electricity in such experiments as (95.) does 

 not result from the specific inductive capacity of cloud, which 

 can differ but little if at all from air. The following experiment 

 is a proof that this effect of the steam in increasing the electricity 

 of a jet of water does not depend on the cold water condensing 

 the steam-cloud. 



177. The fountain, tin pipe, &c. were arranged as in (94.), 

 except that the distance between the lower end of the brass jet 

 of the fountain and the upper end of the tin pipe was diminished 

 to 5*5 inches. Water was placed in the fountain and caused to 

 boil, the air was pumped in, and the glass tube and jet screwed 

 into its place. The fountain was connected with the ground, 

 and the tin pipe with the single-leaf electrometer, and then the 

 cock of the fountain was opened a little to give a stream of suffi- 

 cient force. The bulb of a thermometer was now held in the 

 stream of water just inside the upper end of the tin pipe ; the 

 mercury soon reached 142^ ; the thermometer was removed, and 

 the electrometer was observed to be scarcely affected ; but on 

 now opening the cock of the boiler a little, and so filling the tin 

 pipe with cloud, the quantity of electricity produced by the 

 stream of water was greatly increased, the gold-leaf rapidly 

 striking the conducting plate. The thermometer was again 

 brought into the stream of water as before ; the steam still pass- 

 ing, it marked 149*^ ; the thermometer was now placed in the 

 steam-cloud in the tin pipe and soon fell to 125°. ,a 



178. Of course these numbers given by the thermometer, 

 depending as they do upon the extent to which the cocks were 

 opened, varied in every experiment ; for example, another experi- 

 ment conducted as the foregoing gave the first temperature of 

 the water 154°, the second temperature 156°, and the tempera- 

 ture of the steam-cloud 123°. The increase of electricity pro- 

 duced by the steam-cloud appeared to be quite as great when 

 hot water was discharged from the fountain as when the water 

 was cold. 



179. It should seem there can be now only one property of 

 the steam-cloud to which this increase of electricity can be 

 ascribed, namely, some species of conduction, which, by lowering 

 the electrical intensity of the jet of water, would account for the 

 phsenomenon. Something of this power appears in the experi- 

 ments (43, 52.) in the connexion existing between the tube and 

 the boiler. The following experiment is still less ambiguous. 



180. A large Ley den jar was charged positively and inverted 

 on a proper support, so that the distance between the end of the 

 brass jet of the boiler and the centre of the ball of the jar was 



