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views, that he considers 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 electricity, reflects or scatters rather 
than absorbs light of the wave-length which it radiates, that 
portion of the coronal light, which is polarized and as- 
sumed to be reflected, will be accounted for. I think that 
the recent observations have confirmed the probability of 
these speculations, inasmuch as they have confirmed the facts 
on which these speculations were based. There is one point 
which has not been already noticed, but which seems to me 
to be of some importance. 
If the corona be an electric discharge, the electricity will 
be continually carrying off some of the elements of the sun 
into space where they will be deposited and condensed. 
May not this stream of matter be the cause of the existence 
of small meteors, and supply the place of those which con- 
tinually fall into the larger bodies ? 
“Further Experiments on the Effects of Cold upon Cast 
Iron,” by Peter Spence, F.C.S., &c. 
In resuming these experiments upon the effects of cold 
on cast iron, it is not necessary for me to say that I was led 
to resume them from the apparent undecisiveness of all the 
experiments brought before the Society some time ago, my 
own being included in that category, none of them being so 
free from possible sources of error as to be fitted for finally 
settling the matter. 
In the experiments which I have now to bring before the 
Society I have limited my aim to a single point, namely, as 
to whether the reduction of temperature has any, and if so 
what effect on cast iron in regard to its powers of resisting 
