52 THE WONDERS OF GEOLOGY. Lect. I. 



foreign to our planet. Luminous spots, altogether inde- 

 pendent of the phases, have been seen on the dark parts of 

 the moon ; these appear to be the light arising from the 

 eruption of volcanoes ; whence it has been supposed that 

 meteorites have been projected from the moon by the im- 

 petus of volcanic eruption. For if a stone were projected 

 from our satellite in a vertical line, with an initial velocity 

 of 10,992 feet in a second — a velocity but four times that of 

 a ball when first discharged from a cannon — instead of fall- 

 ing back to the moon by the influence of gravity, it would 

 come within the sphere of the earth's attraction, and revolve 

 around it. These bodies, impelled either by the direction 

 of the primitive impulse, or by the disturbing action of the 

 sun, might ultimately penetrate the earth's atmosphere and 

 arrive at its surface. But from whatever source meteoric 

 stones may come, it is highly probable that they have a 

 common origin, from the uniformity, we may almost say 

 identity, of their composition."* 



These masses present a general correspondence in their 

 chemical composition and appearance, having (with the 

 exception of native iron) a crystalline character internally, 

 and externally a black slaggy crust, as in this specimen 

 from Nanjenoy. 



Obers states that aerolites have been found in tertiary 

 and secondary strata ; if so, we must conclude that before 

 the last arrangement of the earth's surface, meteoric stones 

 had fallen upon it. 



Baron Humboldt observes that aerolites afford the only 

 direct experimental knowledge we possess of any of the 

 specific properties or qualities of matter not belonging to 

 our globe. " Their direction and enormous velocity of 

 projection (a velocity wholly planetary) render it more 

 than probable, that these masses, enveloped in vapours and 



* Connexion of the Physical Sciences, p. 423, 4th edition. 





