DIVISIBILITY OF MATTER ATOMIC THEORY. 63 



Matter, organised into life, furnishes illustrations 

 without end. The living and fossil infusoria the ova 

 of fishes and insects the red corpuscles of the blood 

 (estimated microscopically by billions to the cubic inch) 

 the odours of flowers the millions of germs diffused 

 from the puff-ball of a single fungus these suffice for 

 examples, expressing in their units the marvellous 

 divisibility of matter; and a further marvel in the 

 consideration that these units are themselves organised 

 compounds of smaller and more elementary atoms, 

 each endowed with properties giving it a part in the 

 mechanism of the natural world. In no case have we 

 absolute proof that the ultimate atoms or monads the 

 fjLsyeQr) a^iaipsroL have been reached. In the case of 

 compound bodies, their molecules by division carry us 

 yet farther in the scale of minuteness, until thought 

 becomes involved in that metaphysical web of the 

 Infinite and Indivisible the terminus to all enquiry. 1 



The admission, or rather re-admission, of the atomic 

 theory into all our views of the material world is per- 

 haps the most marked step in the science of our day. 

 The facts as well as the requirements of chemistry have 



1 Lucretius, wonderful both as a thinker and poet, approaches this 

 abstruse point of the infinite divisibility of matter with his wonted 

 felicity in subjecting philosophy to verse (lib. iv. 616). It is one of the 

 many instances where his power of thought (based doubtless in part on 

 prior philosophy) has pointed to conclusions verified more or less by the 

 most recent researches of our own time. Without citing others, I may 

 briefly notice two instances which I have not seen mentioned elsewhere, 

 viz., the passage (lib. ii. 288 et seq.) in which are foreshadowed the 

 recent discoveries of Graham and Tyndall on the diffusibility and pene- 

 trability of different kjnds of matter; and that (lib. ii. 447-50) indi- 

 cating the exact order in which stone, bronze, and iron implements are 

 now shown to have come into the uses of man. 



