107 
“ The Tails of Comets, the Solar Corona, and the Aurora , 
considered as Electric Phenomena, Part II.,” by Professor 
Osboene Reynolds, M.A. 
In the paper which I read before this society, on the 29th 
of November last, I endeavoured to show that it is probable 
that these phenomena are a species of that action known 
as the electric brush taking place in the medium which 
fills space, be it ether or simply gas, or both. The 
reasoning I made use of was, essentially a fortiori. I 
pointed to the fact that tho electric brush as seen in 
the Geissler tubes exhibits similar appearances, and that 
at the times of greatest display on the part of comets 
and the aurora similar conditions are present, such as a 
change in the action of the sun, conditions which, to say 
nothing more, are favourable to electric disturbance. I 
purposely avoided all attempts to explain how the brush 
may be produced, feeling that it was sufficient to point to 
the aurora, which is universally admitted to be electrical, 
as a proof that such phenomena do exist even if we cannot 
explain how. This proof, however, is perhaps not quite 
satisfactory. In order that it may be complete, the other 
phenomena must be produced in the same way as the aurora, 
and this, although possible, is not necessary. An assumption 
which is commonly made respecting the phenomena of the 
aurora cannot be made with respect to the others. This 
assumption assigns the two magnetic poles of the earth as the 
two electrodes between which the electric discharge takes 
place, which forms the aurora borealis and the australis. If 
this assumption be maintained, some other explanation must 
be found for the manner in which electricity may form the 
tails of comets and the corona. It is quite clear that the 
