COMETS, THE SOLAR CORONA, AND THE AURORA. 55 



rubber negatively charged ; and these electricities do not 

 unite instantly there and then, but remain and accumulate 

 in the respective bodies, until collected and brought to- 

 gether again by the conductor. 



Assume, then, that the sun is in the position of the 

 rubber, while the ether is in that of the glass ; then the 

 corona corresponds to the spark or brush which leaves the 

 conductor. On the same assumption the negative elec- 

 tricity of the comet would be more and more set free by 

 the inductive action of the sun as the comet approached 

 it, and would also be driven off by induction in a direction 

 opposite to that of the sun — and, combining with the posi- 

 tive electricity in the ether, would form the tail of the 

 comet, in a manner analogous to that in which a native 

 spark is given off by the lid of the electrophorus. 



I think that a rational account may in this way be given 

 of the manner of the electrical action to which I have at- 

 tributed these phenomena; but I do not consider that 

 the probability of the truth of this electrical hypothesis 

 depends on the value of such an explanation. It is an 

 assumption, based on the manner in which it fits into its 

 place and explains the appearances presented by these 

 beautiful phenomena. 



Since this paper was written, my attention has been 

 called to the fact that Mr. Richard Proctor has published 

 views of these phenomena which somewhat resemble 

 mine. He attributes them in part to electricity, and in 

 part to meteors. There is, however, this fundamental 

 difference between our views — that he regards the tails 

 of comets as consisting of cometary matter, the difficulty 

 of conceiving which was the origin of these speculations. 

 Moreover I can conceive no electric discharge between 

 two meteors without a medium between them ; and if there 

 is a medium, why is there any necessity for meteors ? If, 

 as I see good reason to suppose, gas, when glowing with 



