454 MODERN CHEMISTRY. 



atomic weights, definite for each particular substance, and 

 giving to each its peculiar properties. It is a natural in- 

 ference, confirmed by observation, that of these complex 

 molecules thus differing in stability, some should run hastily 

 into dissolution, others hold tenaciously together, so as to 

 be capable of entering as bases into new combinations with- 

 out losing their identity. From the latter condition we 

 derive the probable theory of compound radicals ; thus 

 merging it in those great laws which govern all the chemical 

 affinities that nature or art place before us. 



The vastness of this subj ect of Organic Chemistry precludes 

 those examples which might animate, as well as illustrate, 

 our review of it. We would willingly adduce some instances 

 of those beautiful series in which, whether we ascend the 

 scale from the simplest, or descend from the most complex, 

 we find organic compounds, infinitely various in properties, 

 produced by the simple addition or subtraction of elementary 

 atoms; each such change in the series defined by strict 

 numerical relations, and capable almost of being expressed by 

 algebraic symbols. A striking example we have in that re- 

 markable series which ascends from olefiant gas the simplest 

 atomical union of carbon and hydrogen through various 

 intermediate chemical compounds, to sugar as the summit of 

 the scale. Each successive step here renders the arrangement 

 of atoms numerically more complex ; but all are so submitted 

 to definite proportions, that the chemist, in dealing with these 

 substances, can predicate exactly what number of atoms must 

 be added or removed, to effect each successive change from 

 one to another. The series of products obtained from com- 

 mon Coal is another striking example of these relations. 

 To naphtha, as the first product, succeed benzule, nitro-ben- 

 zule, aniline, and rosaniline ; the latter yielding, by simple 

 addition of water, that Magenta dye which now gives such 

 splendid colouring to the various tissues from our looms. 



