80 DR GEORGE WILSON ON THE FINITE DrVISIBILITY OF MATTER. 



liermit this self-dividing force to come into plaj', and the result, according to 

 WoLLASTON, Avill show whether the mass iindergoing spontaneous division is inti- 

 nitcl.y divisible or not. This experiment Ave cannot try ; but it has long ago been 

 lierformed for us by the hand of Nature. Our atmosphere has divided itself to 

 the utmost limit which its susceptibility of division permitted, and has thereby 

 tested or ascertained that divisibility for us. Either that is infinite, in which 

 case, the atmosphere must have spread into space, and portions of it will be found 

 surrounding the diiferent heavenly bodies, varying in amount according to their 

 respective dimensions, temperatures and the like. Or it is finite, and the air has 

 found a limit at no great distance from the earth ; for the particles of which it 

 consists, although free, so far as their mutual repulsiveness is concerned, to re- 

 cede from each other, are not equally free to recede from the earth, to which the 

 force of gravitation binds them. They must come to rest accordingly at the point 

 Avhere the attraction of gravitation is equal in amount, while it is opposite in di- 

 rection to the force of repulsion among them ; so that they are balanced in equi- 

 librio between them. Now it appears on making the necessary observations, 

 that probably the Sun, and certainly that Jupiter, is devoid of an atmosphere of 

 the same nature as our own. Therefore, concludes Wollaston, our atmosphere is 

 of finite extent, and consists of particles only finitely divisible. And as the air 

 cannot be supposed to be peculiar in this respect, the conclusion is immediately 

 extended to every other substance, and all matter is inferred to consist of finitely 

 divisible particles, or bond fide atoms. 



It cannot surprise us that so remarkable a paper as Wollaston's should have 

 excited the greatest attention among men of science. If the argument pursued 

 in it were just, the vexed question of the finite or infinite divisibility of matter, 

 which, for some thousand years, physics and metaphysics had alike sought in vain 

 to decide either way, had all the while been answered for us. Every attempt to- 

 Avards the solution of that problem by experiment had failed, not perhaps, be- 

 cause ultimate atomic particles had not been arrived at, by the dividing forces 

 our command, (for this length the inquiry never readied) ; but because, 

 long before the divisibility of a body could be supposed to be exhausted, the 

 products of its division had become invisible to us, and Ave had no test by Avliich 

 to tell Avhen the atoms of a substance had been attained to. Both of these diffi- 

 culties, according to AVollaston, were taken out of the AA^ay, by the mode in Avhich 

 Nature made the experiment. A dividing force co-ordinate Avith the divisibility 

 on which it took effect — finite, if it were finite, infinite, if it were infinite — Avas 

 brought into play. The result of this diAnsion, moreover, could be ascertained, 

 could, in truth, literally be seen ; for it did not take place in a vacuum, but in a 

 space containing bodies, each of which would infallibly indicate the extension of a 

 self-dividing medium at least to itself; and as that, if it were infinitely divisible, 

 must reach to them all in its progress towards infinite division, should it certainly 



