PORTION OF THE COSMOS. AEROLITES. 421 



particles, on our globe, its oceans, and its atmosphere. The 

 luminous vibration which proceeds from the smallest tele- 

 scopic fixed star in a resolvable nebula, to the impression of 

 which our eye is susceptible, brings to us, (as is mathemati- 

 cally shewn by the sure knowledge we possess of the velocity 

 and aberration of light), the evidence of the most ancient 

 existence of matter of which we are cognisant ( 679 ) . By 

 a simple combination of ideas, a luminous impression received 

 from the depths of star-filled space leads us back more than 

 a myriad of ages into the depths of primeval time. The 

 luminous impression given by streams or showers of falling 

 stars, aerolite-discharging fire-balls, or similar igneous me- 

 teors, are of a wholly different nature, since they only kindle 

 or become ignited on arriving at or entering the Earth's 

 atmosphere; and, on the other hand, the falling aerolite 

 affords the only instance of actual material contact with 

 something foreign to our globe. " Accustomed to know 

 non-telluric bodies solely by measurement, by calculation, and 

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

 ment that we touch, weigh, and submit to chemical analysis, 

 metallic and earthy masses appertaining to the world with- 

 out," to the celestial spaces external to our planet ; and 

 that we find in them our native minerals, rendering it pro- 

 bable, as was already conjectured by Newton, that substances 

 belonging to one group of cosmical bodies, or to one plane- 

 tary system, are for the most part the same ( 68 ). 



We are indebted to the diligence of the Chinese, and to 

 their habit of recording everything in registers, for the oldest 

 chronologically determined falls of aerolites. Accounts ot 

 this kind go back to 644 years before our era ; therefore to 

 the time of Tyrtseus and of the second Messenian War of the 



