126 CELESTIAL PHENOMENA. 



of the innermost of Saturn's satellites, or of Ceres, with the 

 enormous volume of the Sun, the relations of great and 

 small disappear to our imagination. The sudden blazing 

 up and subsequent extinction of stars in Cassiopea, Cygnus, 

 and Ophiucus, have already led to the admission of the 

 possible existence of non-luminous cosmical bodies. Con- 

 densed in smaller masses, the asteroids revolve around 

 the sun, intersect like comets the paths of the great 

 luminous planets, and become ignited when they enter or 

 when they approach the outermost strata of our atmosphere. 

 Our intercourse with all other cosmical bodies with all 

 nature beyond the limits of our own atmosphere is, exclu- 

 sively, either through the medium of light, and of radiant 

 heat intimately united with light ( 90 ), or through the 

 mysterious force of attraction exerted by remote bodies, ac- 

 cording to the measure of their distance and their mass, on 

 our globe, its ocean, and its atmosphere. But if in shooting 

 stars and meteoric stones we recognise planetary asteroids, 

 we are enabled by their fall to enter into a wholly different, 

 and more properly material, relationship with cosmical objects. 

 Here we no longer consider bodies acting upon us exclu- 

 sively from a distance, by exciting undulatory vibrations of 

 light or heat, or by causing, or themselves undergoing, mo- 

 tion by the influence of gravitation ; but we have actually 

 present the material particles themselves, which have 

 come to us from the regions of space, have descended 

 through our atmosphere, and remain upon the earth. A 

 meteoric stone affords us the only possible contact with a 

 substance foreign to our planet Accustomed to know non- 

 telluric bodies solely by measurement, by calculation, and 

 by the inferences of our reason, it is with a kind of asto- 



