Mr. W. G. Armstrong on the Electricity of Effluent Steam. 55 



The visible transmission of electricity from the jet to the 

 cock, in this experiment, furnishes convincing proof that the 

 positive electricity which we find in the jet is not developed 

 until the steam assumes the form of a visible vapour; and it 

 shows also that the steam, even in its transparent state, is, as 

 I have already surmised, a tolerable conductor of electricity. 



I will now venture to offer such an explanation of the elec- 

 trical phaenomena of effluent steam, as I conceive to be most 

 consonant with the experiments I have described in this and 

 my preceding communication. 



Independently of the experimental proofs which have been 

 adduced of the neutral state of the steam up to the instant of 

 its transformation into an opake vapour, the water and the 

 steam must be so thoroughly intermixed in the boiler of a 

 locomotive engine, as to render it impossible for the steam to 

 become electrified with positive electricity without immedi- 

 ately imparting it to the water. 



I assurae,'then, as a fact, established both by reason and ex- 

 periment, that the steam is in a neutral state in the boiler ; 

 and I think I am equally supported in saying, that it does 

 not exhibit positive electricity, after leaving the boiler, so 

 long as it retains its aeriform nature. 



We learn from experiment that a development of negative 

 electricity in the boiler accompanies the emission of the steam ; 

 and since the negative development in the boiler is obviously 

 independent of the subsequent condensation of the steam, it 

 follows, that if the effluxion of the steam could be effected 

 without permitting any condensation to take place, we should 

 then have a development of negative electricity in the boiler 

 without any simultaneous development of positive electricity ; 

 and in like manner if the ejected steam were subsequently 

 condensed into water, we should then have a liberation of 

 positive electricity without a concomitant liberation of negative 

 electricity. 



These conclusions are entirely incompatible with the theory 

 of two electric fluids, but are quite reconcileable with the 

 hypothesis of a single fluid. It seems perfectly rational and 

 consistent with analogy to suppose, that the immense aug- 

 mentation of volume which takes place when water ex- 

 pands into steam of any ordinary density, should occasion a 

 greatly increased capacity for electricity ; and consequently, 

 that the (juantity of electricity which suffices to produce a 

 neutral or saturated state in water, should be (juite inadequate 

 to sustain that condition when the water is converted into 

 steam. Upon this supposition the steam as it forms in the 

 boiler will absorb electricity from the adjacent conductors in 



