14 On Isomeric Transmutation, and the Nature of 



ever, Mr G. J. Knox, who not only accepted Dr Brown*s 

 statements as true, so far, at least, as the appearance of sili- 

 con was concerned, but advocated the probability of such an 

 occurrence ; on grounds, however, quite opposed to those Dr 

 Brown himself built upon. Mr Knox's views are unfortu- 

 nately not known to us fully, although it is more than a year 

 since they were laid before the Royal Irish Academy. Owing 

 to a peculiarity in the mode of publishing its transactions fol- 

 lowed by that Society, the paper has not yet been printed ; 

 and the only shape in which its contents have reached us is 

 that of an imperfect and insufficient abstract in one of our 

 own journals.* Mr Knox conceives that the nitrogen of the 

 paracyanogen, and not its carbon, is the source of the silicon 

 which appeared in Dr Brown''s experiments. His own words 

 are the following : after referring to certain experiments of Sir 

 H. Davy, which seem to him. to warrant the belief that nitrogen 

 is a compound body, he says, " The latest experiments which 

 bear upon this subject, and from which I received the idea 

 which led me to this investigation, are those of Dr Brown, 

 * upon the Conversion of Carbon into Silicon,' — an explanation 

 of phenomena which appears to me most unreasonable, and con- 

 trary to all chemical analogy : while the supposition of the car- 

 bon having reduced the nitrogen, is not only a simple, but an 

 unavoidable conclusion to arrive at, if nitrogen be a compound 

 substance. To determine, by experiment, the correctness or 

 incorrectness of this idea, it were only necessary to reduce 

 nitrogen by some other substance than charcoal ; and should 

 silicon result from its decomposition, the problem might be 

 considered to be solved.*' f 



Mr Knox then describes several experiments made with a 

 compound of hydrogen, nitrogen, and potassium, heated in 

 different ways with iron, in two of which silicon appeared, 

 although no carbon was present. The compound Mr Knox 

 employed, he terms the " ammonia-nitruret of potassium," 

 by which I understand him to signify the amidide of potassium 

 (KNH^) of other authors. He rejects one of the two experi- 

 ments where silica appeared, as inconclusive as to its anoma- 



Chemical Gazette, September 1843. t Ibid., p. 574. 



