Carbon, Silicon^ and Nitrogen, 13' 



sible to help wishing that the latter chemist's scheme of 

 Elemental Isomerism should prove the truer of the two. For 

 Dr Brown supplies us with but a one- edged weapon for con- 

 quering nature, while Professor Johnston puts in our hands a 

 two-edged sword, smiting both ways, and increasing twofold 

 our power over matter. 



Meanwhile, Dr Brown is the only chemist who has had 

 faith and courage enough to test the reality of Elemental 

 Isomerism, by endeavouring to transmute one of the elements 

 into another. This, he believes, he has succeeded in doing 

 in the case of carbon and silicon. His experiments have been 

 made upon certain compounds of the former body with nitro- 

 gen, which he subjected to various modifying processes ; one 

 general principle, however, runs through them all, which may 

 be explained in a few words. By a special process, instituted 

 for the purpose, or as a product of a general process for 

 transmutation, he obtained paracyanogen, a body consisting 

 of carbon and nitrogen, in the proportion of twelve parts of the 

 former to fourteen (by weight) of the latter ; or of two atoms 

 of carbon to one of nitrogen. The atomic weight and exact 

 constitution of this body are unknown, but Dr Brown, as we 

 have already seen, supposes it to be a duplication of cyanogen, 

 and, therefore, to contain four atoms of carbon to two of ni- 

 trogen. When this body is treated in various ways, of which the 

 simplest, and the only one we need consider, is that of heat- 

 ing it out of contact with air, alone, or in contact with sub- 

 stances (such as platina or carbonate of potass) having a 

 strong attraction for silicon, its two atoms of nitrogen, 

 according to Dr Brown, pass away unchanged, and its four 

 atoms of carbon combine together, and form silicon. To some, 

 perhaps, the view intended, and its relation to the isomerism 

 of confessedly compound bodies, will be clearer, if they suppose 

 for the moment that carbon is a compound of two elements, 

 which are united in it in certain proportions, and in the same 

 ratio, but in a multiple four times higher in silicon. 

 . The greater number of chemists refused to acknowledge 

 that silicon was, or could be, produced from paracyanogen ; 

 and, joining issue with Dr Brown on this point, oiffered 

 no opinion on his theory of the origin of the silicon which 

 appeared in his experiments. There was one chemist, how- 



