On the Connexion of Electricity leitk Evaporation. 45 



needle which is unmagnetized in the commoji acceptation of the 

 word. 



20. It may be necessary to add, that the prism with which 

 I operated was one of crown glass about four inches in length, 

 and that it was held with both hands at the distance of about 

 half an inch from the surface of the water, in such a posi- 

 tion that the red rays of the spectrum were nearest the 

 observer. R. V. 



IX. On the Connexion of Electricity with Evaporation. By 

 Mr. G. A. RowELL. 



To the Editors of the Philosophical Magazine and Journal. 



Gentlemen, 



IN a paper read before the British Association at Glasgow, 

 I endeavoured to explain the various phaenomena of rain, 

 the aurora, and magnetism, by the hypothesis, that each par- 

 ticle of vapour takes with it from the earth its proportion of 

 electricity, according to its expanded surface; that if con- 

 densed within the electrical attraction of the earth, the sur- 

 charge of electricity is withdrawn and the vapour is deposited 

 as dew ; but if it rise out of the electrical attraction of the earth, 

 and is then condensed, the electricity, being insulated, forms 

 an atmosphere around each particle of vapour ; which sur- 

 charge of electricity not only suspends the vapour by its lio-ht- 

 ness, but also repels the neighbouring particles of vapour, 

 and prevents the formation of rain; and on the removal (by 

 any cause) of the electricity inclosing the vaporous particles, 

 the repulsion is removed, and the particles of vapour then at- 

 tract each other and form rain. 



The discovery of the electricity of steam has strengthened 

 my opinion, and the following experiment was made to prove 

 that evaporation would not go on so freely from an insulated 

 vessel as from an uninsulated one : believing the experiment 

 is new, I respectfully submit it to the attention of the readers 

 of your valuable Journal. 



In a warm room over an oven in daily use, I suspended by 

 silk threads two shallow vessels, eight inches and a half in 

 diameter, containing eight ounces of water each; a small cop- 

 per wire was hung from one vessel to the earth to take off the 

 insulation, both vessels being similarly suspendetl in every 

 other respect; after being suspended twenty-five hours the 

 insulated vessel had lost two ounces eleven dwts. and fifteen 

 grains; and the other vessel three ounces six dwts., showing 

 an excess of evaporation from the non-insulated one of four- 

 teen dwts. nine grains. 



