92 THE ELECTRIC ELEMENT. 



has physical and probably complex relations to our 

 atmosphere can hardly be doubted, though, unless 

 under the supposition of its identity with the electric 

 element, we are wholly ignorant of their nature. But 

 this very ignorance becomes itself an argument for 

 identity. I know no theory better fitted to expound 

 the various aspects and conflicts of atmospheric elec- 

 tricity than that I have stated. The interaction of 

 the two circumambient agents, ether and the atmo- 

 sphere, and the connexions of both, but especially of 

 the ether, with the solid matter of the globe, afford 

 relations various and complex enough to meet any 

 theoretical demand. 



In dealing with this hypothesis it will be seen that 

 I have put all the main points interrogatively, as befits 

 a matter in which there is nothing yet susceptible of 

 proof. It is not, however, too much to hope for a time 

 in the future when some higher mastery may be ob- 

 tained over these abstruse problems, and when the 

 great forces that move the material world, including 

 gravitation among them, may be submitted to some 

 more general law, giving unity to phenomena which are 

 incongruous or dissevered to our present knowledge". 1 



In a letter to Sir J. Herschel (July 1870), in reply 

 to one from him on this subject, I summarise as 

 follows the purport of the foregoing paper. 



1 The hypothesis I have sought in this paper to uphold has found a 

 powerful advocate in M. Savowing, whose excellent memoir, Sur la 

 Physique Moderns ('Revue des Deux Mondes,' November and December, 

 1866), 1 have just peruRed. There are points in his argument which he 

 has put more forcibly than I have done. There are certain points in 

 my statement of the question to which he has not adverted. 



