On the Meteors of ISih 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 aerolites, 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 aerolites are known to consist in a 

 great 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 bumid 

 again. The fact that such electrical appearances were unusually stri- 

 king at the time of the occurrence under review, and a few hours after, 

 being granted, we should still have to inquire, 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 (ew magnetic 

 observations have been communicated to the public. 



11. Of the several facts collected under the head of concurrent 

 phenomena, possibly no one may prove of any importance ; and yet 

 the contrary is also possible. The fall of rain without clouds- 



Vol. XXV.—No. 2. 52 



