( 229 ) 



XIV. Experimental Researches on the Production of Silicon from Paracyanogen. 

 By SAMUEL M. BROWN, M.D. Communicated by Dr CHRISTISON. 



(Read 3d May 1841.) 



IN a Memoir on the Preparation of Paracyanogen submitted to the Royal 

 Society some weeks ago, I laid down the proposition, that two equal 'and similar 

 molecules may enter into the state of chemical union, the combination produced 

 being indissoluble by every known agent of analysis ; and I endeavoured to estab- 

 lish this proposition partly on certain abstract physical considerations, and partly 

 by a series of experiments on the production of paracyanogen by the decomposi- 

 tion of the bicyanide of mercury under pressure and at high temperatures.* 



The processes now to be described were deduced through a series of hypo- 

 thetical inferences from the proposition referred to ; and the experimental results 

 at which I have arrived seem to support the hypothesis which conducted to them. 

 But as the theory in question cannot be properly enunciated without the confir- 

 matory evidence of farther investigations of a similar kind, and as the facts al- 

 ready discovered are, on the one hand, independent of all theory, and, on the 

 other, must appear of themselves sufficiently startling to the chemist, I have 

 thought it advisable to make my observations known now in their simplest form, 

 and waive for the present what I conceive to be their theoretical explanation. 



In my former paper it was stated, that I had been led to infer from experi- 

 ment that two familiar substances, long and universally considered distinct ele- 

 ments, are really modifications of one and the same material form. Having fre- 

 quently repeated and varied the experiments which led to this conclusion, and 

 having endeavoured in every conceivable way to discover some source of fallacy, 

 but in vain, I now venture to announce, as the result of my inquiries, that carbon 

 and silicon are isomeric bodies, and that the former element may be converted 

 into a substance presenting all the properties of the latter. 



The present communication consists of five parts. The first treats of the 

 production of silicon from paracyanogen ; the second, of the formation of amor- 

 phous mixed compounds of silicon with copper, iron, and platinum, by the reac- 

 tion of paracyanogen on these metals ; the third, of the quantity of nitrogen se- 



* Transactions of the Royal Society of Edinburgh for 1840-41. 

 VOL. XV. PART I. 3 Q 



