12 REVIEW AND BIBLIOGRAPHY 



In the electric furnace either BaCOa or BaO may be employed. BaC2 



forms dark colored crystals, sp. gr. = 3.75, decomposed by water, 



thus : — 



BaC2+2 H20=C2H2+Ba(OH)2. 



At high temperatures the carbides of the alkaline-earths react violently 



with the halogens. 



LITERATURE. 



Maquenne. Sur un carbure defini du baryum. C. R. 114, p. 361. 



Maquenne. Sur une nouvelle preparation de I'acetylene. C. R. (1892) 115, p. 558. 



BuLLiER. Deutsches Reichspatent, 77,168. 



MoissAN. Etude des acetylures cristallises de baryum at de strontium. C. R. (1894) 



118, p. 683, or Chem. Centrbl. (1894) 65, pt. i, p. 856, or Bull. Soc. Chim. [3] 11, 



p. 1007. 



BORON AND CARBON. 



Two carbides of boron have been described, BC or BoCo, and ByC. 

 According to Moissan two compounds are formed in the electric furnace, 

 one of which is permanent and resists the action of KCIO3-I-HNO3, while 

 the other compound is broken down by this treatment. He has given 

 the more stable compound the formula BgC. It is produced when boron 

 and certain boron compounds are heated with carbon in the electric fur- 

 nace. Black, shining crystals, sp. gr. 2.51, harder than carborundum, and 

 with it new facets may be cut upon diamonds. CI at high temperatures 

 decomposes it with deflagration, chloride of boron and carbon resulting. 

 Very slowly oxidized at 1000°, it is not acted upon by mineral acids, nor 

 by S, P, N, Br, or I. 



Miihlhauser heated together in an electric furnace boric-anhydride and 

 carbon. The product he treated twice with hot HCl, then with HF, and 

 H2SO4. There remained a graphite-like mass, which by analysis showed 

 the composition BC or B2C2. The compound is fusible at a high tempera- 

 ture and is decomposed by fusion with alkali. 



LITERATURE (BeC). 



Moissan. Action de Tare electrique sur le diamant, le bor amorphe et le silicium 



cristallise. Bull. Soc. Chim. [3] 11, p. 993, or C. R. 117, p. 423, or Abs. J. Chem. 



Soc. (1894) 66, pt. 2, p. 42. 

 Moissan. Preparation et proprietes du borure de carbone. C. R. (1894) 118, p. 556, 



or Abs. J. Chem. Soc. (1894) 66, pt. 2, p. 279, or Bull. Soc. Chim. (1894) [3] 11, 



p. 998. See also 

 Hampe. Ueber das Bor. Ann. Chem. (1876) 183, p. 75. 

 WoHLER and St. C. Deville. Ann. de chim. (1858) [3] 52, p. 63. 

 (B2C2) MiiHLHAUSER. Ztschr. anorgan. Chem. 5, p. 92, or Chem. Centrbl. {1893) 64, 



pt. 2, p. 747, or Abs. J. Chem. Soc. (1893) 64, pt. 2, p. 570. 



CALCIUM AND CARBON. 



In 1862 Wohler gave a method of producing acetylene gas from a com- 

 pound of calcium and carbon. This compound was prepared from a zinc- 



