PHYSICAL SCIENCE. 39 



however, even imagination utterly fails to reach the reality, 

 reason accepts this next to infinite divisibility of matter, and 

 the conception of polarities and mutual relations of atoms so 

 constituted, as the sole method of expounding the phenomena. 

 Such subtility of their elementary parts may fairly be stated 

 as an integral necessity in the composition and changes of 

 all the material bodies which surround us. 



Had we room here, we might dwell on the astonishing 

 results already derived from this new method of chemical 

 enquiry, through the atomical combinations of matter ; and 

 those especially which bring new laws of action and com- 

 bination into view ; such as the doctrines of isomorphism, 

 atomic substitution, homologous series of compounds, com- 

 pound radicals, catalysis, &c., which we owe to the labour 

 of Berzelius, Mitscherlich, Liebig, Hofmann, Brodie, and 

 other chemists. Each one of these laws, thus based on the 

 atomic doctrine, is a special example of that spirit of profound 

 research which marks the science of our day; while the 

 growth of organic chemistry, in sequel to labours pursued on 

 this principle, is perhaps the most wonderful of the results 

 thence attained. No surer test of truth in any law than its 

 power of predicting events or effects yet unknown. When, 

 for instance, we find in the different series of organic acids, 

 where every step of change is made in multiple ratios of 

 numerical exactness, that certain void places, left in the first 

 construction of the series, are afterwards filled up by the 

 discovery of compounds answering precisely to the numerical 

 conditions required, we see at once how much has been done 

 towards the deciphering of this secret scroll of nature. Had 

 the mystical arithmetic of the Pythagoreans and Alexandrian 

 Platonists been converted from a dreamy speculation into 

 sober reality, it would have fallen short of the actual results 

 which this part of science has disclosed to us. 



But though especially demonstrated in chemical affinities, 



