272 BENZENE. 



Disulphodiphenylicacid, C 12 H 8 (S0 2 .OH) 2 , is form 

 ed by dissolving diphenyl in concentrated sulphuric 

 acid. Long, colorless prisms, that fuse at 72.5. Very 

 easily soluble in water. The potassium salt, C 12 H 8 .S 2 6 K 2 

 + 2 JH 2 0, crystallizes in large, colorless prisms, moder 

 ately difficultly soluble in cold water. The barium 

 and lead salts are insoluble in water. 



Diphenylbenzene, C 18 II 14 = C 6 H 4 j g^ Is pro 

 duced like diphenyl by the action of sodium on a mix 

 ture of mono- and dibrombenzene. Colorless, crystal 

 line mass. Fusing point, 205 ; boiling point, 400. 



Mercuryphenyl, (C 6 H 5 ) 2 Hg. Is produced, when, to 

 a solution of monobrombenzene in benzene, sodium- 

 amalgam is added, and the whole then heated for a 

 few hours in connection with an inverted condenser ; 

 the formation takes place particularly easily in the 

 presence of a little acetic ether. (See Mercury ethyl, 

 p. 62). Colorless, rhombic prisms, that become yellow 

 in contact with the air. Fusing point, 120. Insolu 

 ble in water, easily soluble in chloroform, carbon bisul 

 phide, and benzene, more difficultly in ether and boil 

 ing alcohol. &quot;When carefully heated, it can be par 

 tially sublimed without decomposition ; it is, however, 

 partially resolved into mercury, benzene, diphenyl, and 

 carbon. Treated with two molecules chlorine, bromine, 

 or iodine, it is resolved into monochlor-, brom-, or 

 iodobenzene, and mercury chloride, bromide, or iodide ; 

 treated with only one molecule of the halogenes, or 

 heated with mercury chloride, bromide, or iodide and 

 alcohol at 110, it is converted into mercurymono- 

 phenyl chloride, C 6 H 5 .IIg.Cl (rhombic plates, fusing point, 

 250), bromide, C 6 H 5 .Hg.Br (rhombic plates, fusing 

 point, 275-276), and iodide, C 6 H 5 .Hg.I (rhombic 

 plates, fusing point, 265-266). Hydrogen, sodium, 

 and alkaline sulphides regenerate mercury phenyl from 

 these compounds. &quot;When the chloride is heated with 



