304- Mr. R. Phillips on the Electricity of Condensation, 



I have no doubt a spark can be obtained ; that is, the elec- 

 tricity is powerful enough to pass from particle to particle 

 through a visible interval of air. But the electricity so ex- 

 isted in the condensed vapour before the positive electricity 

 passed to the drops of water, that the positive and negative 

 particles were separated by an insensible space ; from which 

 it follows, that the electricity must then have been much 

 weaker; and this increase of tension can, as it appears to me, 

 only have taken place " in the way suggested by the Com- 

 mittee of Physics of the Royal Society." 



But it may perhaps seem that this exalted tension is pro- 

 duced rather by the running together of the electrified drops 

 of water than of the vapour particles; however, it must be 

 observed, that the combination of two or more drops of the 

 electrified water into one mass, so as to produce a diminished 

 surface, is electrically equivalent to an approximation of the 

 minute vapour particles which they contain, and on which we 

 may imagine for this purpose the charge to exi§t. 



It immediately appears from the foregoing, that the simple 

 formation of cloud cannot generate any electrical force ex- 

 terior to the cloud, as the positive and negative forces which 

 it may contain (for the electro-current of condensation shows 

 that after a time they may neutralize each other) must balance 

 one another ; and it can only be when the positive particles 

 aie removed from the negative by the carrying action of rain, 

 that the static electric force is developed. It is, however, very 

 possible that a cloud may collect and condense the general 

 electricity of the atmosphere, or it may by specific induction 

 cause the inductric action of the heavens to be concentrated 

 under the cloud. It is, I think, from one or both of these 

 causes that Mr. Birt's remark must be explained, " that ge- 

 nerally before a shower an atmospherical conductor indicates 

 the presence of negative electricity." (Phil. Mag., vol, xxxvi. 

 p. 167.) And with regard to the subject of nubification, I 

 would remark that the negative as well as the positive elec- 

 tricity of condensation must be equally considered. 



I will now state some new experimental results at which I 

 have arrived bearing on this subject. I find that saline matter, 

 which when discharged with the steam readily extinguishes 

 the ordinary frictional electricity of steam, does not prevent 

 the boiler from becoming positive as before (70,), and that 

 some water must escape with the steam in order that the 

 boiler may become positive. I think these experiments will 

 demand that we regard the positive state of the boiler and the 

 negative state of the steam as produced by the friction of steam 

 on the wetted surface of the orifice of the jet. I have also 



