OF THE METALLIC CARBIDES. 1 5 



KoRDA. Acetylene and calcium carbide. Ztschr. Elektrochem. (1896) p. 175. 



Pelissier. Ztschr. Elektrochem. (1896) p. 225. 



Pelissier. L'eclairage electrique (1896), VIII, p. 500, and IX, p. 442. 



Grehaut. Melanges explosifs d'acetylene et d'air. C. R. (1896) p. 832. 



Clarke. Manufacture of calcium-carbide, U. S. pat. 552,890, and for generating acety- 

 lene, U. S. pat. Jan. 14, 1896, 556,736, Mar. 24, 1896. 



King and Wyatt. Apparatus for generating acetylene, U. S. pat. 562,401, June 23, 

 1896. 



King and Wyatt. Process of forming calcium carbide, U. S. pat. 562,402, June 23, 

 1896. 



King and Wyatt. Electric furnaces, U. S. pats. 562,400 ; 562,403 ; 562,404, June 23, 

 1896. 



WiLLSON. (Gas patents, etc.) 553,443. Jan. 21, 1896, and 553,550, Jan. 28, 1896 ; 

 555,198, Feb. 25, 1896. 



CERIUM AND CARBON. 



A carbide of the composition CeCs results by heating cerium formate or 

 oxalate in an apparatus from which the air is excluded. When the resi- 

 due from this operation is extracted with HCl a compound remains of the 

 above composition, which is not soluble even in hot, concentrated acids. 

 Many chemists doubt the existence of this compound. 



The carbide which Moissan has produced in the electric furnace has 

 the formula CcgC. It is prepared from Ce02 and sugar carbon. It 

 forms transparent crystals, sp. gr. 5.23. When acted upon by water it is 

 decomposed, evolving C2H0, CH4, C2H4, and the residue extracted with 

 ether contains a small amount of fluid and solid hydrocarbons. The 

 reaction must obviously be very complex. 



LITERATURE. 



Gmelin. Carbide of cerium (!•). Handbook of Chemistry, Vol. Ill, p. 264 (Watt's 



translation, 1849). 

 Berzelius. Lehrbuch der Chemie (1836), III, p. 495. 

 Delafontaine. Jsb. Chem. (1865) P- 176- 

 Pettersson. Supplement to the report of the Royal Academy of Sweden (1895), II, 



2 series, number i. 

 Moissan. Preparation et proprietes du carbure de cerium. C. R. 122, p. 357, or Chem. 



Centrbl. (1896) 67, pt. i, p. 686, or Abs. J. Chem. Soc. (1896) 70, pt. 2, p. 422. 



CHROMIUM AND CARBON. 



When chromium is heated in an electric furnace for ten to fifteen min- 

 utes with a large excess of carbon, with a current of 70 volts and 350 

 amperes, there is produced Cr3C2 ; brilliant laminae, greasy lustre, sp. gr. 

 5.62, not acted upon by concentrated or dilute HNO3 or aqua regia. 

 Fused KNO3 attacks it vigorously, not so KOH. It is not decomposed 

 by H2O, hot or cold. It is harder than the topaz. Som jwhat soluble 

 in dilute HCl. 



Cr4C obtains as long, shining needle-like crystals which are found upon 



