considered Geographically , Statistically y and Cosmically. 451 



If the disturbance was confined to the magnetic dust, iron-masses 

 would fall ; if to the diamagnetic dust, a non-ferruginous stone ; 

 if it should extend to both classes simultaneously, a blending of 

 the two characters would ensue in the precipitate, and a rain of 

 ordinary meteoric stones would take place. 



"As favouring this view, we are struck with the rounded, 

 hailstone-like form of many of the particles of composition (even 

 though consisting of widely dijQPerent substances) in nearly all 

 stones, and even in many of the iron masses. Nor are these 

 shapes to be referred to fusion ; they evidently depend upon a 

 cause analogous to that which determines the same configuration 

 in hailstones themselves. 



" The occasional raining of meteorites might therefore on such 

 a theory be as much expected as the ordinary deposition of 

 moisture from the atmosphere. The former would originate in 

 a mechanical elevation of volcanic ashes and in matter swept 

 into the air by tornadoes, the latter from simple evaporation. In 

 the one case, the matter is upheld by magneto-electric force ; in 

 the other, by the law of difi*usion which regulates the blending 

 of vapours and gases, and by temperature. A precipitation of 

 metallic and earthy matter would happen on any reduction of 

 the magnetic tension ; one of rain, hail or snow, on a fall of 

 temperature. The materials of both originate in our earth. In 

 the one instance they are elevated but to a short distance from 

 its surface, while in the other they appear to penetrate beyond 

 its furthest limits, and possibly to enter the interplanetary 

 space ; in both cases, however, they are destined, through the 

 operation of invariable laws, to return to their original reposi- 

 tory.'' 



That large falls of dust and other substances do occasionally 

 take place is without doubt, as well as that volcanic dust is some- 

 times shot up into the air and carried great distances ; but that 

 it is this same matter which is afterwards sustained or solidified 

 by magnetic action, there is no proper evidence to prove. The 

 fall of a meteorite is usually preceded by an explosion, and a 

 scattering J rather than uniting, of fragments or bodies ; evidence 

 rather of some larger part, or whole, entering our atmosphere from 

 without, and bursting or cracking from sudden heating, into 

 larger or smaller particles according to the original nature and 

 texture of the body itself. Humboldt, in his ' Cosmos,' decidedly 

 expresses the opinion that the nature of these meteoric stones, 

 and the phsenomena accompanying their fall, are such as to pre- 

 clude the idea of their having been condensed from minute mat- 

 ter or from a gaseous state, in a short interval of time : he also 

 states that meteoric masses kindle and become luminous at ele- 

 vations which must be supposed to be almost entirely deprived 



