341 



midofF. (Partie Scientifique.) Livr"» xiii. et xiv. des planches. 



— By the Author. 

 Transactions of the Zoological Society of London. Vol. i. Part 3. 

 Proceedings of the Zoological Society of London. Nos. 73 to 90. 



— 3i/ the Society. 



Zd MdylUl. 

 Right Hon. Lord GREENOCK, V.P., in the Chair. 



The following Communications were read : — 



1. Experimental Researches on the Production of Silicon from 

 Paracyanogen. By Samuel Brown, M.D. Communi- 

 cated by Dr Christison. 



In his paper on Paracyanogen read to this Society at an earlier 

 period of the present session, the author announced that he con- 

 sidered he had succeeded in proving, that two familiar bodies, uni- 

 versally believed to be distinct elements, are modifications of one 

 and the same elementary form. In the present paper, he an- 

 nounced that the bodies in question are carbon and silicon, and 

 gave a detailed statement of the investigations by which he had 

 been led to this conclusion. 



1. Silicon may be obtained from uncombined paracyanogen. — 

 When paracyanogen, prepared from bicyanide of mercury by heat 

 under pressure, as described in his former paper, was subjected to 

 prolonged heat in a closed tube of German glass, a dark-brown 

 substance was obtained, which presented all the diagnostic cha- 

 racters of silicon. More especially, it was incombustible before the 

 blowpipe, underwent no change on being projected into fused 

 chlorate of potash, but dissolved with effervescence in fused car- 

 bonate of potash, forming a white saline substance, in which silica 

 was detected by its ordinary reagents. The same experiment 

 was performed with the like result on a larger scale in a porcelain 

 crucible ; and the quantity of silicon produced came within a very 

 small amount of the carbon contained, by theory, in the paracy- 

 anogen employed. When paracyanogen is heated with carbonate 

 of potassa, silicic acid is obtained at once. A variety of experi- 

 ments were described, the purpose of which was to obviate all fal- 

 lacy that might be supposed to arise from silica being present in 

 the vessels employed. 



2. Siliciurets may be obtained by the reaction of paracyanogen 

 on metals When bicyanide of mercury was heated in tubes 



