THE SMITHSONIAN INSTITUTION. 167 



the only opinion that can be entertained in reviewing the facts of the 

 case. 



As regards the igneous character of the minerals composing meteor- 

 ites, nothing remains to he added to what has already been said ; in 

 iact no mineralogist can dispute the great resemblance of these min- 

 erals to those of terrestrial volcanoes, they having only sufficient 

 difference in association to establish that although igneous, they are 

 extra-terrestrial. The source must also be deficient in oxygen, citlier 

 in a gaseous condition, or combined, as in water ; the reasons for so 

 thinking have been clearly stated as dependent ui)on the existence of 

 metallic iron in meteorites — a metal so oxydizable that in its terrestrial 

 associations it is almost always found combined with oxygen, and 

 never in its metallic state. 



What, then, is that body which is to claim common parentage of 

 these celestial messengers ? Are we to look at them as fragments of 

 some shattered planet whose great representatives are the thirty-three 

 asteroids between Mars and Jupiter, and that they are "minute out- 

 riders of the asteroids," (to use the language of K. P._ Greg, jr.,* in 

 a late communication to the British Association,) which have been 

 ultimately drawn from their path by the attraction of the earth ? For 

 more reasons than one this view is not tenable. Many of our most 

 distinguished astronomers do not regard the asteroids as fragments 

 of a shattered planet ; and it is hard to believe, if they were, and the 

 meteorites the smaller fragments, that these latter should resemble 

 each other so closely in their composition — a circumstance that would 

 not be realized if our earth was shattered into a million of masses, 

 large and small. 



If, then, we leave the asteroids and look to the other planets, we find 

 nothing in their constitution, or the circumstances attending them, to 

 ^ead to any rational supposition as to their being the original habita- 

 tion of the class of bodies in question. This leaves us, then, but the 

 moon to look to as the parent of meteorites ; and the more I contem- 

 plate that body the stronger does the conviction grow, that to it all 

 these bodies originally belonged. 



It cannot be doubted, from what we know of the moon, that it is 

 constituted of such matter as composes meteoric stones ; and that its 

 appearances indicate volcanic action, which when compared with sim- 

 ilar action on the face of the globe, is like ^Etna contrasted with an 

 ordinary forge, so great is the difference. The results of volcanic 

 throws and outbursts of lava are seen, for which we seek in vain any- 

 thing but a faint picture on the surface of our earth. Again, in the 

 support of the present view it is clearly established that there is neither 

 atmosphere nor water on the surface of that body, and, consequently, 

 no oxygen in those conditions which would preclude the existence of 

 metallic iron. 



Another ground in support of this view is based on the specific 

 gravity of meteorites — a circumstance that has not been insisted on ; 

 and although of itself possei^ing no great value, yet, in conjunction 

 with the other facts it has some weight. 



* See the able paper of E. P. Greg, jr., in the Loud. Phil. Mag. 



