Carbon, Silicon, and Nitrogen. 9 



of the elementary bodies, — Professor Johnston* in 1837 ; Dr 

 Samuel Brown,t and Professor Kane in 18414 



Dr Brown's theory, which I consider first, as it is a scheme 

 of transmutation by synthesis, is founded upon the existence 

 of a class of isomeric bodies, in which, while the equipropor- 

 tionality of identical elements occurs, the number of atoms 

 combining to produce this, is different in each member of the 

 group. Thus, there exists a series of compounds of carbon 

 and hydrogen, containing these bodies in the proportion of 

 atom to atom. This is satisfied in the lowest, which is 

 termed methylene, by 2 atoms of carbon to 2 of hydrogen ; 

 in the next olefiant gas, by 4 to 4 ; in the third oil gas, by 

 8 to 8, and in a fourth cetene, by 32 to 32. The volatile oils 

 referred to previously, form so far at least, a similar series ; 

 in them the elements are also carbon and hydrogen, in the 

 proportion of five atoms of the former to four of the latter. In 

 oil of citron this is doubled, or we have Cjo Hs ; in oil of cubebs 

 tripled, or 0^^ Tl^^ ; in turpentine quadrupled, or Q^q Hig. 



Groups of isomeric bodies of this kind are supposed by Dr 

 Brown to be formed by successive duplications or doublings. 

 The lowest member of the series, by combining with itself, 

 produces a first multiple ; this, by uniting with itself a se- 

 cond ; that, by combining with itself a third ; and so on ad 

 infinitum. It is not essential, however, to the truth of this 

 view, that a full series of duplicate multiples should be shewn 

 to exist, provided no body is found to manifest an unequivo- 

 cal departure from the rule : the gaps which occur in the 

 known series may be filled up by future discoveries. Dr 

 Brown thinks he has established the truth of his view by ex- 

 periment, in regard to the isomeric compounds of carbon and 

 nitrogen, cyanogen and paracyanogen ; the latter of which he 

 believes to be produced by the former combining with itself. 

 In like manner he represents the 55 so-called simple sub- 

 stances as a group, or a series of groups, of isomeric bodies, 

 produced by the element of lowest atomic weight (which may 



* Report of the Seventh Meeting of the British Association, pp. 163- 

 215. 



t Transactions of the Royal Society of Edinburgh, vol. xv. pp. 165- 

 X76, and 229-246. 



X Elements of Chemistry, p. 377. 



