392 NAPHTHALENE. 



easily in hot alcohol and in ether. Distils over readily 

 with water. Burns with a luminous sooty flame. 

 Combines with picric acid, forming a compound, 

 C io H 8 + C 6 H 3 (N0 2 ) 3 0, which crystallizes in stellate, 

 yellow needles. When oxidized with nitric acid, it 

 yields phtalic acid (p. 362). When heated with phos- 

 phonium iodide to 170-190, it yields a liquid hydro- 

 carbon, C 10 H 12 ; boiling point, 201. 



"With chlorine it forms products of addition and sub- 

 stitution. 



Naphthalene dichloride, C 10 H 8 .C1 2 , pale yellow 

 oil, heavier than water, and insoluble in it. 



Naphthalene tetrachloride, C 10 H 8 .C1 4 , transparent 

 rhombohedral crystals ; fusing point, 182 ; difficultly 

 soluble in alcohol and ether. 



Chlornaphthalene tetrachloride, C 10 H 7 C1.C1 4 , 

 klinorhombic prisms ; fusing point, 128-130. 



Dichlornaphthalene tetrachloride, C 10 II 6 C1 2 .C1 4 , 

 klinorhombic prisms ; fusing point, 172. 



When these chlorine compounds are boiled with 

 alcoholic potassa, hydrochloric acid is given off and 

 chlorine-substitution-products of naphthalene are 

 formed. These, when further subjected to the action 

 of chlorine, again form addition-products and substi- 

 tution-products, containing more chlorine. 



Monochlornaphthalene, C 10 H 7 C1. Colorless liquid ; 

 boiling point, 250-252. 



a-Dichlornapthalene, C 10 H 6 C1 2 . Crystalline mass ; 

 fusing point, 35-36 ; boiling point, 282. 



j3-Dichlornaphthalene, C'H 6 C1 2 . Colorless prisms ; 

 fusing point, 68 ; boiling point, 281-283. 



Trichlornaphthalene, C 10 IPC1 3 . Brittle prisms; 

 fusing point, 81. 



