888 ESSENTIAL OILS. 



and sublimes. Soluble in 200 parts of cold, and in 22 parts 

 of boiling water, from which it crystallizes on cooling. 



By treating terebene by chlorine, M. Deville formed two 

 liquid chlorinated compounds, which he names chloroterebene, 

 C 20 H 12 C1 4 ; and monochloroterebene, C 20 H 14 C1 2 . He also formed 

 bromoterebene, C 20 H 12 Br 4 . Terebene does not form a hydrate 

 like the essence. The essence treated with chlorine gives a 

 chlorinated compound, which M. Deville names chlorocamphene, 

 of the same composition as chloroterebene, but differing in density 

 and other properties. 



Colophene is an additional product besides terebene, of the 

 action of concentrated sulphuric acid upon the essence. It dis- 

 tils over after the terebene, on urging the heat so as to bring the 

 viscid mass in the retort to a state of strong ebullition, as a viscid 

 oil, of a clear yellow colour, which re-distilled several times 

 alone, and once (if contaminated with sulphur) from the alloy 

 of potassium and antimony, constitutes colophene. Colophene 

 is colourless by transmitted light, but possesses a kind of 

 dichroism and may be seen of a deep indigo blue colour, a pro- 

 perty which can be recognised in all its compounds. Its density 

 is 0.940 at 48, and 0.9394 at 77. It is isomeric with the 

 essence of turpentine. Its boiling point is about 590 or 600; 

 the density of its vapour could not easily be taken with exact- 

 ness, but was certainly not less than twice that of oil of turpen- 

 tine. Assuming the density as double, the atom of colophene 

 will be C 40 H 32 , its combining measure 4 volumes. This oil is 

 also one of the products of the rapid distillation of colophony 

 or the resin of turpentine, and was named colophene on that 

 account. 



Colophene absorbs hydrochloric acid, but the hydro chlorate 

 is a feeble combination, and is deprived of its acid by chalk. 

 By distilling the impure hydrochlorate from barytes, M. Deville 

 obtained an isomeric oil, which he considers the colophilene 

 of colophene. It did not appear, however, to possess the 

 dichroism of the latter body. Colophene also absorbs chlorine 

 with avidity, without any disengagement of hydrochloric acid, 

 and is converted into a resin, soluble in alcohol and crystal- 

 lizable, having very much the appearance of colophony, and 

 which is named chlorocolophene, C 40 H 32 C1 4 . It is in fact colo- 

 phony in which 4 atoms of oxygen are replaced by 4 atoms of 



