188 Notices of the Labours of Continental Chemists. 



Power of rotation = 0, which is the case with all the other 

 compounds of this class. The monohydrobromate is a co- 

 lourless fluid; specific gravity = 1*021 at 24°; obtained by 

 acting on tereben with hydrobromic acid, and purifying by 

 means of chalk, animal charcoal and chloride of calcium. 



The bihydrobromate is obtained with the camphen com- 

 pound by acting on oil of turpentine with hydrobromic acid ; 

 it is difficult to procure in a pure state ; its power of rotation 

 could not, therefore, be accurately determined. The mono- 

 hydriodate is obtained in the same manner. Sp.gr. = 1*084 

 at 21°; decomposes by exposure to the air. The bihydrio- 

 date can only be obtained mixed with the camphen compound. 



By the action of chlorine and bromine on tereben, chlorides 

 and bromides are produced. The specific gravities are re- 

 spectively, 1-360 and 1*978 at 20°. Formulas C 20 H 24 CI 8 , 

 C 20 H 24 Br 8 ; eight atoms of hydrogen have been replaced by 

 eight atoms of chlorine or bromine. By distilling these com- 

 pounds two others may be obtained, C 20 H 28 CI 4 , or C 20 H 28 Br 4 . 

 The monochloride of tereben, C 20 H 28 CI 4 , has a specific gra- 

 vity = 1*137 at 20°. 



The action of iodine appears to be more complicated. 



Hydrobromate and hydriodate of camphen may be obtained 

 in the same manner as the hydrochlorate ; the former is solid ; 

 power of rotation = — 0*4264. The hydriodate is a fluid. 

 Sp.gr. at 15°= 1*0597; power of rotation = —0*1597. They 

 both decompose by exposure to the air. Formulae C 20 H 32 + 

 H 2 Br 2 , and C 20 H 32 + H 2 ! 2 . 



By the action of chlorine on hydrochlorate of camphen, a 

 fluid body is first produced, the formula of which is C 20 H 24 CI 8 , 

 CI 2 H 2 ; this body then loses hydrochloric acid and forms a 

 solid crystallized substance, chloride of camphen, C 20 H 24 CI 8 . 

 Chloride of camphen has no power of rotation ; sp. gr. at 8° = 

 1*50; melts at 110 — 115°. By its distillation another chlo- 

 ride is formed, the formula of which is probably C 20 H 28 CI 4 . 



Oil of turpentine is decomposed by chlorine and bromine, 

 and forms two bodies, whose formulas are C 20 H 24 CI 8 , and 

 C 20 H 24 Br 8 . The power of rotation of the chlorine compound 

 is (for the yellow ray) + 0*2854. 



Colophen is formed, as above stated, by the action of sul- 

 phuric acid on oil of turpentine; it passes over at a tempera- 

 ture above 200°. Formula C 20 H 32 ; specific gravity at 9° = 

 0*940; boils at 310— 315°; sp.gr. of its vapour is 11*13. 



Colophen is also formed by the rapid distillation of colo- 

 phonium, but is always impure. Deville supposes that Un- 

 verdorben's pinic and sylvic acids are respectively oxides of 

 colophen and tereben ; for, by the distillation of colophonium, 



