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paper of Mr, Mitchell, if Mr. Byrne will excuse me for saying so. He knows I 
am a sincere friend of his, and that I should be glad to hear him upon 
any point connected with astronomy, but pray let us have it at the proper 
time and place. (Hear, hear.) 
Mr. Warington. — I should like to ask one question of Mr. Mitchell. I 
never before heard the theory started, which seems a probable one, that the 
origin of the shooting stars is electrical rather than cosmical. And I would 
ask, whether there is anything in the phenomena of the aurora borealis simi- 
larly periodical, as to particular seasons or days of the year, with the peri- 
odical display of meteors ? Because, if there is any such periodicity here 
also, it would very materially help out the hypothesis. I am not aware 
whether there is anything of the kind, and perhaps Mr. Mitchell will 
tell us. 
The Bev. Walter Mitchell. — In reply to Mr. Warington, I may state 
that I am unacquainted with any period days marking a great display of 
aurora borealis. I only wished to point out several analogies between the 
two phenomena. In some latitudes the aurora is almost nightly visible, like 
the display of falling stars in other latitudes. Then there is something similar 
in the intermission of the brilliant displays of both phenomena — the aurora 
appearing in lower latitudes for a few years, and then disappearing altogether, 
like the maxima exhibition of falling stars. With regard to the period days 
of falling stars, I may state that these are not the only meteoric phenomena 
(using the term meteor in its widest sense), which are periodic. There are 
certain latitudes where the return of the monsoons and the change of the 
trade winds occur with such regularity as to allow their prediction nearly to 
a day. In defence of the theory first put forth by Soldani as to the terres- 
trial origin of meteorites, I think many facts might be urged, though I doubt 
whether they would be considered sufficient to demonstrate its truth. The 
majority of meteorites are admitted to be identical in composition with solid 
masses ejected from our own volcanoes. These masses, for aught we know, 
might have been projected in a state of vapour, and might remain for some 
time uncondensed in our upper atmosphere. Or, if condensed, they might 
remain, as Professor Shepherd has stated, in minute subdivision till condensed 
into a solid mass by some such known agency as electricity. We know that 
some metals do evaporate like water, and their vapour ascends like that of 
water into the atmosphere ; mercury is an instance. We are ignorant,, be- 
cause our analysis is not sufficiently sensitive to tell us, how many of the 
constituents of meteorites may be diffused through our atmosphere. If not 
in a state of vapour, yet in a state of minute subdivision, such constituents 
could be carried by the upper trade winds thousands of miles. Vessels on 
the Mediterranean and in the Atlantic sometimes pass through a red fog for 
days together. A red dust may be collected on the rigging of ships, and 
Professor Ehrenberg has shown that this dust is. composed for the most part 
of the shells of foraminiferse, which have been wafted thousands of miles from 
the plains of South America by the upper trade winds. These fogs, covering 
as they do some hundreds of square miles, must contain many tons of material 
