268 Dr, Reynolds on Meteors. 



2dly. The situation of the earth's surface in respect to the 

 sun, the influence of his rays thereon, and the nature of the 

 elements or compounds on which these rays act : 



And 3dly. The identity that exists between the component 

 parts of meteoric stones, and the elements that enter abundantly 

 into the composition of our globe ; and, by several other facts 

 and arguments. 



Under my first general specification, I will select such prin- 

 ciples from the established doctrines of philosophy, as have an 

 immediate bearing on the subject ; without engaging in any of 

 those subtle speculations in which certain recondite properties 

 of matter, or the identities of quality and body are affirmed or 

 denied. 



Thus, 1st. Heat is the universal cause of fluidity and volati- 

 lity in bodies ; hence no solid can assume the state of gas, until 

 it absorbs, or unites with, a certain portion of caloric ; and the 

 subtilty and volatility of compounds thus formed, will be in a 

 due ratio to the quantity of caloric they employ. 



2dly. The heat employed to maintain a body in the gaseous 

 state, is said to be latent or fixed, and may be regarded as an 

 ocean or atmosphere of fire, holding the ultimate particles of 

 the body in a state of extreme division, and wide separation, 

 from which they can be driven only by some change in the af- 

 finities or condition of the compound. 



3dly . If the latent heat in a gaseous compound be suddenly 

 abstracted, as in explosion, its escape is attended with the 

 emission of light and sensible heat, when the volatilized parti- 

 cles held in solution being no longer able to maintain the state 

 of gas, suffer approximation in a due proportion to the quan- 

 tity of caloric they have lost. 



4thly. Caloric, in reducing solids to the state of gas, lessens, 

 but cannot in any case, as far as we know, totally destroy their 

 gravitating force ; the diminution of this force, however, being 

 in a direct proportion to the quantity of heat employed. — 

 Hence the following inferences may be fairly drawn, as they 

 seem to be in unison with the relative dependence and har- 

 mony existing between the material elements of this globe, and, 

 I believe, are contradicted by no direct experiments ; viz. that 



