21 S Ol'servaficns on the Fall of Stones 



think that aerolites had a terrestrial origin. But all these ex- 

 planations must still be subdivided, according as we refer the 

 formation of the aerolites to this or that cause. Thus we find 

 an:ong those who have assigned an extra-atmospheric origin to 

 these stones : 



1. That some, with Pliny, make them come from the sun, 

 since, according to thei)i, they have a black colour, or look as 

 if burnt, colore adtisio. 



2. That others, with Chladni, regard them as small isolated 

 planets, or rather, with M. Lagrange, as fragments of small 

 planets. 



0. Lastly, that the rest, with the illustrious author of the 

 JMecaniqtte C6leste, consider them as bodies darted from the 

 moon, — an opinion adopted by most English writers. 



Those, on the contrary, who have assigned an atmospheric 

 origin to them, have thought, 



1. That they were produced in our atmosphere by the com- 

 bustion of inflammable gases, which Jiold suspended or dissolved 

 metallic and earthy particles. 



2. Or that they have been produced in the same way as metals 

 or earths are formed in plants, as the experiments of Schroeder 

 and Crell have proved. These naturalists observed, that causing 

 plants to vegetate in sulphur and charcoal, the metals or the 

 earths which are generally found in these substances were formed 

 by the act of vegetation. 



As to those wlio have ascribed a terrestrial origin to aerolites, 

 some have admitted that these substances preexisted in the places 

 where they were found, and had been merely afl'ected bv the 

 lightning: others, that they come from volcanos, and that they 

 were a species of lava. 



The opinion which tends to regard aerolites as formed by 

 new combinations operated in the atmosphere by the contact 

 of all the bodies incessantly carried up by evaporation, is as vet 

 50 little known, that it is the only one with which we shall now 

 concern ourselves. 



The authors of this hypothesis have in the first place observed, 

 that the fall of aerolites does not appear to have taken place 

 equally at all seasons ; for in sixty-five or seventy of these falls, 

 the epoch of which is well kno\vn, nearly two-thirds have hap- 

 pened in the months of June, July, and August. Lastly, they 

 also prove that in all the winter months the falls of stones have 

 been less frequent than in a single month of summer. 



The same observation, which demonstrates the influence of 

 the seasons on aerolites, applies equally to the different times of 

 the day : thus, fro.n a catalogue drawn up with great care, of 

 all the falls of meteoric stones hitherto known, seven only fell 



between 



