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tail of a comet cannot be due to a discharge between two 
electrodes situated on the comet itself. In the same way, 
from the position occupied by the corona, it can hardly be 
due to electricity passing between two electrodes on the sum 
In fact, if a comet’s tail is electrical, it is due to a discharge 
of electricity of one kind or another from the comet, which 
for the time answers to one of the electrodes only. The 
same may be said of the corona and the sun. If we could 
observe the aurora from a point distant from the earth, 
it is very probable that we should find the same to be 
the case, but whether this would be so or not, an assump- 
tion has been made as to the cause and nature of the 
aurora, which will answer just as well for the corona and 
comet’s tails : it is, that the sun acting by evaporation or 
otherwise, causes continual electric disturbance between the 
earth and its atmosphere, the solid earth being negatively 
charged and the atmosphere positively, and that the aurora 
is the reunion of these electi’icities taking place in the 
atmosphere. 
Now as has been already said, this assumption will serve 
for the comets and the sun as well as for the aurora. If 
there is a continual electric disturbance between the sun 
and the medium in which it is placed, so that the sun be- 
comes negatively and the medium positively charged, the 
reunion of these electricities would form the corona. It 
must not be supposed that I assume the sun to be a reser- 
voir of electricity which it is continually pouring into space. 
I consider that the supply of electricity in the sun is kept 
up by some physical action going on between the sun and 
the medium of space, whereby the sun becomes negatively 
charged, and the medium positively. 
