THE 

 LONDON, EDINBURGH and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[THIRD SERIES.] 



MARCH 1850. 



XXII. On the connexion of Atmospheric Electricity iioith the 

 Condensation of Vapour. By William Radcliff Birt*. 



THE intimate connexion which appears to subsist between 

 the quantity of water diffused or suspended in the atmo- 

 sphere, and the electric tension as exhibited by an atmosphe- 

 rical conductor, renders it not only interesting but ^important 

 to trace either theoretically, or by means of experiment, the 

 process of the formation of cloud and its resolution into rain, 

 and the development of electricity as connected with each of 

 these processes. 



It is not my intention in the present paper to detail any new 

 experiments, nor to bring before the reader the results of any 

 recent investigations on this interesting subject, further than 

 as they may incidentally throw light on any remarks which 

 it may be found necessary to indulge in, in prosecuting the 

 object now proposed. I shall consequently place before the 

 reader, so far as my knowledge extends, what has been already 

 written on the subject; and I must therefore claim his indul- 

 gence, especially in a work like this, for treading beaten ground, 

 and presenting nothing novel to his notice. The office I pro- 

 pose lo myself is that of a lens, which, concentrating the scat- 

 tered rays of light, renders them more powerfully efficient in 

 illuminating in some cases obscure objects. 



The first writer I shall quote is John Read of Knightsbridge. 

 In his work on atmospheric electricity published in 1793, at 

 page 22 he has this reniark relative to the relation of air to 

 electricity : " I have no idea, much less suppose, that any, 

 even the least quantity of electricity does ever come from air 

 itself; for there is reason to think, that air as air, independent 

 of the other substances, is unable to furnish any particle of 

 • Communicated by the Author. 



Phil. Mas. S. 3. Vol. 36, No. 2*2. March 1850. M 



