1 6 REVIEW AND BIBLIOGRAPHY 



the surface of ingots of metallic Cr or in cavities existing in such ingots. 

 It is harder than quartz ; sp. gr. 6,75 ; melts at a higher temperature 

 than Pt. One of the above carbides is also said to result by passing 

 CS2 vapors over hot Cr. Certain compounds of Fe, Cr, and C are known, 

 such as FcjCrgCs and CfaFeCg. 



LITERATURE. 



Deville and Debray. (Foot-note) Ann. de chim. [3] 56, p. 408. 



MoissAN. Nouvelles recherches sur le chrome. C. R. (1894) 119, p. 185, or Abs. J. 



Chem. Soc. (1894) 66, pt. 2, p. 452. 

 MoissAN. Bull. Soc. Chim. [3] 11, p. 13, and p. 1014. 

 MoisSAN. Ann. de chim. (1896) [7] 8, p. 559. 

 Behrens and Van Linge. (On the chromium ferro-carbides) Recueil trav. chim. 



Pays-Bas, 13, p. 155, or Abs. J. Soc. Chim. (1894) 66, pt. 2, p. 451. 



COBALT AND CARBON. 



Over thirty years ago Thompson described a compound containing 

 about 4% C, which was very hard and brittle, of bismuth color, sp. gr. 

 8.43. It was made by heating C02O3 and argol in a closed carbon cru- 

 cible for several hours. 



LITERATURE. 



Thompson. Ueber die Fabrication von Kobalt und Nickel. Chem. Centrbl. (1863) 



p. 956, or Le Technologiste (1863) p. 337. 

 MoissAN. (Foot-note) Bull. Soc. Chim. [3] 11, p. 13. 



COLUMBIUM AND CARBON. 



A double compound of columbium carbide and nitride of this compo- 

 sition, 3CbC2CbN, has been mentioned by Joly. 



LITERATURE. 



JOLY. Sur le combinaisons du niobium et du tantale avec I'azote et le carbone. Bull. 

 Soc. Chim. (1876) [2] 25, p. 506, or C. R. 82, p. 506, or Jsb. Chem. (1876) p. 279. 



COPPER AND CARBON. 



An explosive compound to which various formulas have been given 

 results by passing acetylene through ammoniacal copper solutions. Very 

 little carbon is taken up by direct heating of copper and carbon. A little 

 copper is said to be taken up in combination during the poling process of 

 refining copper. Some very good work has been done recently upon the 

 acetylids in this country and England, but with not altogether accordant 

 results. The formulas usually given for copper acetylide are C2CU2 and 

 C2CU2-I-H2O. See especially .A'm^r, Am. Chem. J. 14. 



LITERATURE. 



QuET. (On certain explosive compounds of Cu and C.) C. R. 46, p. 903, and Ann. 

 Chem. 108, p. 116, also 



