170 THE CHEMISTRY OF CREATION. 



but it is right to add, that others extend its limits 

 much more, even as far as from one to two hun- 

 dred miles. Dr. Wollaston, in a valuable paper 

 upon the Finite Extent of the Atmosphere,* 

 enters "into an elaborate discussion of the sub- 

 ject, and proves that if the atmosphere were 

 illimitable it must necessarily pervade all space, 

 and accumulate around the sun, moon, and 

 planets. Now, astronomical observations are 

 clear in demonstrating that no atmosphere, or at 



o j. 



any rate none similar to our own, surrounds most 

 of the larger planets, which ought to collect a 

 considerable mass of this gaseous matter around 

 them, in consequence of their size. From such 

 and similar reasonings we are led to conclude 

 that our air has a real limit. The fact also rests 

 upon deductions of chemical importance. The 

 laws of the great atomic theory forbid that 

 infinite divisibility of matter implied in the 

 supposition of such extreme rarefaction of air 

 as is demanded by the theory that it lias no 

 bounds. It is held, for instance, as certain, 

 that we cannot subdivide matter beyond a cer- 

 tain point ; at this point, its particles are called 

 atoms, and these atoms have a certain size and 

 weight. Applying the same reasoning to the 

 air, it is considered that there is a point at 

 which it cannot be expanded further ; and this 

 * Philosophical Transactions, 1822. 



