84 On the Ongin of Meteoric Stones. 



appear to exist there only in very small proportion, and it is 

 only, perhaps, the constant tendency of the atmosphere to an 

 equilibrium which conveys any thither. 



In many places inflammable gases, perhaps hydrogen, may 

 ascend to the higher regions. Do they find there others with 

 which they have little affinity, little or no union will take place- 

 But, by the movements which indubitably occur in these higher 

 regions, such vapours may be arranged in extended strata, and, 

 when they are inflamed at the one extremity by an accumulated 

 electricity, become falling stars, or, when the accumulation is 

 very great, form larger fire-balls. 



Lastly, at times, a great quantity of metallic vapours, or such 

 as are the products of earthy matters, may be here and there col- 

 lected, and then, by an accumulated electricity, be determined ta 

 return to the solid state, which would be the origin of meteoric 

 stones. And we have shewn above that the spaces requisite for 

 the formation of very heavy masses, are indeed great, abstractly 

 considered, but yet form a proportionally small part of the 

 aerial regions, and hence, in the great operations of Nature con- 

 nected with the atmosphere, do not exceed the limits of prcA)a- 

 bility. 



But bow comes it that such vapours, on their return to the solid 

 state, do not resolve themselves into an infinitely fine dust, instead 

 of being precipitated in large compact masses? This appears to 

 me to be the natural consequence of the properties of the matters 

 themselves. In solids, the attraction of cohesion is beyond compa- 

 rison greater than their gravitation ; in fluids, on the contrary, it 

 is less in the same proportion. Hence, when a fluid is precipitat- 

 ed, as water in rain, each particle, when formed, will obey the 

 law of gravitation, consequently descend, and, only in the act of 

 falling, be augmented by the running of several into each other. 

 But, if that which is precipitated or formed be of a solid nature, 

 a very large quantity of cohesive power is set free, at the mo- 

 ment of transition, which must necessarily draw together into 

 one mass, all the gaseous matter. To this also is to be added 

 the consideration, that the same matter, which, as an elastic 

 fluid, occupied a space of many thousand cubic roods, on being 

 reduced to the space of a few cubic inches, gives out a great 

 quantity of heat. Hence the solid body cannot fail to be, at the 



