1 88 CONTINUITY. 



to secure as much accuracy as can, in the present state of 

 knowledge, be attained by such observations. 



The number of known asteroids, or bodies of a smaller 

 size than what are termed the ancient planets, has been so 

 increased by numerous discoveries, that instead of seven we 

 now count eighty-eight as the number of recognised planets, 

 a field of discovery with which the name of Hind will be 

 ever associated. 



The smallest of these is only twenty or thirty miles in 

 diameter, indeed cannot be accurately measured ; and if we 

 were to apply the same scrutiny to other parts of the hea- 

 vens as. has been applied to the zone between Mars and 

 Jupiter, it is no far-fetched speculation to suppose that, in 

 addition to asteroids and meteorites, many other bodies 

 exist, so that the space occupied by our solar system may be 

 dotted up with planetary bodies varying in size from that of 

 Jupiter (1,240 times larger in volume than the earth) to that 

 of a cannon-ball or even a pistol-bullet. 



The researches of Leverrier on the intra-Mercurial planets 

 come in aid of these views ; and another half-century may, 

 and not improbably will, enable us to ascertain that the now 

 seemingly vacant interplanetary spaces are occupied by smaller 

 bodies, which have hitherto escaped observation, just as the 

 asteroids had until the time of Olbers and Piazzi. But the 

 evidence of continuity as pervading the universe does not stop 

 at the results of telescopic observation ; chemistry and physical 

 optics bring us new proofs. Those meteoric bodies which 

 have from time to time come so far within reach of the earth's 

 attraction as to fall upon its surface, give on analysis metals 

 and oxides similar to those which belong to the structure 

 of the earth they come as travellers bringing specimens of 

 minerals from extra-terrestrial regions. 



In a series of papers recently communicated to the French 

 Academy, M. Daubree has discussed the chemical and mine- 

 ralogical character of meteorites as compared with the rocks 

 of the earth. He finds that the similarity of terrestrial rocks 

 to meteorites increases as we penetrate deeper into the earth's 

 crust, and that some of the deep-seated minerals have a com- 

 position and characteristics almost identical with meteorites 



