10 On Isomeric Transmutation ^ and the Nature of 



be the lowest at present known to us hydrogen^ or a lower and 

 more truly elemental body), forming successive combinations 

 in the way already mentioned, so as to reach from, or through 

 hydrogen, which we call 1, up to gold which is 199. times 

 higher. To prevent any mistake, I quote Dr Brown's own 

 words :* — ■" This view of isomerism, and the relation of 

 cyanogen to paracyanogen, is farther recommended by the 

 consideration, that it affords a practical foundation for a likely 

 hypothesis of the constitution of the so-called chemical ele- 

 ments, and points out the way in which such a hypothesis 

 may be either established or overthrown by experimental ob- 

 servation. Let it be supposed that several of the elemental 

 groups are so many series of isomeric forms, and it is at once 

 to be inferred, that heat, electrolysis, and reagents, shall all 

 be incapable of decomposing them, as has been found in the 

 actual practice of the laboratories of modern Europe, by in- 

 numerable trials. If, to take one instance, sulphur (16 or 2) 

 be an isomeric form of oxygen (8 or 1), which it as much re- 

 sembles in chemical properties, as it is conformably contrasted 

 with it in mechanical condition, it must be impossible to ex- 

 tract oxygen from it by any analytical force which has yet 

 been discovered ; and the only method in which it shall be 

 possible to prove that such is the mutual relation of these 

 two elements, shall be to have recourse to synthesis, and 

 convert oxygen into sulphur. It is within the scope of this 

 hypothesis that the various elements may be all isomeric forms 

 of one truly elementary substance." 



Dr Brown's scheme of elemental reduction may be termed 

 one by isomeric synthetic transmutation. You will observe, 

 that he supposes transmutation to take place only by syn- 

 thesis, and in one direction ; so that an element possessing 

 a certain atomic weight, may form, by uniting with itself, 

 another possessing a higher combining proportion ; but the 

 reverse cannot occur. Oxygen, ' which is eight, may double 

 itself into sulphur, which is sixteen ; but sulphur cannot halve 

 itself into oxygen ; carbon may quadruple itself into silicon, 

 but silicon cannot quarter itself into carbon. All the other 



* Trans. Royal Society, vol. xv. p. 176. 



