On the Meteors of 13th November. 409 
analogous to the metallic bases of the alkalies, potassium for exam- 
ple, which could have undergone combustion under the circumstan- 
ces in which the meteors appeared to undergo this process. Could 
bodies constituted like known 4erolites, falling from any supposed 
height in space into the atmosphere, generate heat sufficient, by the 
abrasion or condensation of the air, to dissipate them in a cloud of 
smoke before they reached the earth? 
If we could establish the affirmative of this question, we should at 
once be able to trace the ground of connexion between phenomena 
of this kind and magnetism, since 4erolites are known to consist in a 
reat measure of native iron, A number of other very interesting 
results would follow, respecting the aurora borealis. 
10. That the air was in a state unusually favorable to the devel- 
opment of Electricity, is very evident from the facts recited on p. 
397. Such a state of the atmosphere is always consequent on so 
sudden a change of temperature and humidity from warm to cold, 
and from wet to dry. The air thus becomes a more perfect insula- 
tor, and electricity is accumulated on various bodies, from which it 
is given out in sparks on the approach of an uninsulated conductor, 
or emitted in streams to the air itself as soon as that becomes humid 
again. The fact that such electrical pepenranone were unusually stri- 
king at the time of the ler review, and a few hours after, 
being granted, we should still have to al whether the electricity 
were a cause or a consequence of the meteors, or whether it were 
merely a subordinate effect of the change of weather. 
Similar remarks may be made with respect to any magnetic influ- 
ence which may have been detected. Should a connexion be tra- 
ced between the apparent motions of the meteors and the laws of 
terrestrial magnetism, this discovery would throw light on the mo- 
tions of these bodies, but would still leave the greater part of the diffi- 
culties, such as their nature and origin, unsettled. 
But the known connexion of the aurora borealis with terrestrial 
magnetism, and the obvious connexion of the phenomenon in question 
with auroral appearances, afford reasonable grounds for examining 
the magnetic indications with the greatest attention ; considerations, 
which add to the regret already adverted to, that so few magnetic 
ee have been communicated to the public. 
. Of the several facts collected under the head of concurrent 
_ possibly no one may prove of any importance ; and yet 
the contrary is also tai The fall of rain without clouds 
Vou. XXV.—No. 2 2 
