190 



234. MERCURIC CYANIDE. HgCy 2 . (Bi cyanide of Mercury.) 



a. White prismatic crystals. 



235. IODIDE, MERCUROUS. Hg I. (Proto-iodide, Green Iodide of 



Mercury.) 



a. Greenish-yellow powder. (Hydrargyri lodidum, P.L.; 

 . Hydrargyri lodidum Viride, B.P.) 



236. IODIDE, MERCURIC. Hg I 2 . (Red Iodide of Mercury, Bitiiodide 



of Mercury.) 



a. Bright red crystalline powder. (Hydrargyri lodidum 



Rubrum, P.P.) 



b. Prismatic crystals, prepared by sublimation. 



237. NITRATE, MERCUROUS. Hg 2 (N0 3 ) 2 , 2H 2 0. (Protonitrate of 



Mercury.) 



a. Crystallized. 



b. Crystalline powder, a basic salt 3Hg 2 0, N 2 5 , 3H 2 0. 

 Note. For means of distinguishing between the protonitrate and the 



basic salt, see Fownes, Chemistry, p. 405. 



238. OXIDE, MERCUROUS. Hg 2 0. (Protoxide, Subovide,. or Grey 



Oxide of Mercury.) 

 a. Greenish-black powder. 



239. OXIDE, MERCURIC. Hg 0. (Monoxide of Mercury, Red Oxide of 



Mercury, Red Precipitate.) 



a. Red crystalline powder. 



b. Orange-red powder, levigated. 



c. Ochraceous powder, prepared by precipitation from 



mercuric chloride. (Hydrargyri Oxydum Flavum, B.P. 

 App.) 



240. SULPHATE, MERCURIC. Hg S0 4 . 



a. White crystalline powder. 



241. SULPHATE, BASIC. 3 HgO S 3 . (Yellow Subsulphate of Mercury.) 



a. Bright-yellow powder. (Turbith Mineral.) 



242. SULPHIDE. HgS. (Bisulphuret of Mercury.) 



a. Crystalline lumps, prepared by sublimation. 



b. Powdered. (Vermilion, Cinnabar.) 



Note. For specimens of native cinnabar, see central case, No. 8. 



243. SULPHIDE WITH SULPHUR. 



a. Black powder. (Ethiops Mineral.) 



244. SULPHOCTANATE. Hg (C IS" S) 2 . (Sulphocyanide of Mercury.) 



a. White powder. 



Note. For preparation of this salt, see Watts, Diet. Chem., vol. v., 

 p. 508. 



