OF THE METALLIC CARBIDES. 2$ 



PLATINUM AND CARBON. 



No platinum carbide has been produced by Moissan in his electric fur- 

 nace. Pt at that temperature takes up some carbon, but upon cooling 

 gives it up as graphite and without forming a definite compound. PtC2 

 is mentioned in a number of chemical publications, as is also PtSgC. 

 This platinum sulphocarbide is produced by leading a stream of H or N 

 saturated with CSo vapors over spongy platinum at a temperature some- 

 what below dark red heat. The product is black and finely divided, 

 neither HCl or HNO3 attacks it and aqua regia is almost without effect. 

 Heated in a stream of oxygen, SO,, CO2, and Pt result. 



LITERATURE. 



Zeise. [PtC2] Ueber Acechlorplatin, nebst Bemerkungen uber einige andere Products 

 der Einwirkung zwischen Platinchlorid und Aceton. J. prakt. Chem. (1840) 20, 

 p. 209. 



Gmelin. (Watt's trans., 1849) Handbook of Chemistry, VI, p. 146. 



Fischer. Kastner's Archiv, 14, p. 148. 



ScHUTZENBERGER. [PtS2C] Sur un sulpho-carbure de platine. C. R. (1890) iii, 

 P- 391- 



POTASSIUM AND CARBON. 



K2C2 is formed by the direct action of carbon and potassium at a red 

 heat. It is decomposed by water, yielding acetylene. Davy prepared it 

 nearly ninety years ago by means of electric heat, and described his pro- 

 duct before a London Society in 1808. He made it from graphite and 

 potassium by heating them together in a glass tube in an atmosphere of 

 hydrogen. The product is described as being somewhat like graphite in 

 appearance, infusible at red heat, taking fire in the air, potassium oxide 

 being formed and leaving a black residue. Strongly effervescent with 

 water, giving off a gas which Davy thought was hydrogen. This is the 

 first carbide of which we find record. Davy repeated his experiments, 

 using potassium and willow charcoal. 



LITERATURE. 



Gilb. Ann. (1810) 35, p. 433. 



Davy. Ueber Kohlenstoffkalium und einen neuen Doppelt-Kohlenwasserstoff. Ann. 



der Pharm. (1837) 23, p. 144. 

 Berzelius. Lehrbuch der Chemie (1836), II, p. 315, and (1844), H, P- 84. 

 Gmelin. (Watt's trans., 1S49) Handbook of Chemistry, III, p. 17. 

 Berthelot. Sur une nouvelle classe de radicaux metalliques composes. Bull. Soc. 



Chim. (1866) V, p. 182, and Ann. Chem. 139, p. 150, and Jsb. Chem. (1866) p. 5x4- 



RHODIUM AND CARBON. 

 Moissan states that the metals of this group, Rd, Ir, Pd, and Pt, form 

 no carbides in the electric furnace ; for, while these metals dissolve car- 

 bon readily under such conditions, they give it up in the form of graphite 

 upon solidifying, no carbide resulting. 



