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of camphene hydrate. In like manner as camphene hydrochloride, bornyl- 

 and /sobornyl chlorides react with milk of lime. But, whereas bornyl 

 chloride gives an almost quantitative yield of camphene hydrate, isobornyl 

 chloride yields hardly anything except camphene and a very little cam- 

 phene hydrate. The behaviour of camphene hydrochloride being midway 

 between that of the two other bodies, Aschan assumes the last-named to 

 represent a mixture of two hydrochlorides, «- und /^-camphene hydro- 

 chloride, of which the ^-modification, when treated with weak alkalies, 

 yields camphene hydrate, while the /^-modification yields camphene. 

 Assuming this view to be correct, bornyl chloride would consist chiefly 

 of «-, and isobomyl chloride chiefly of /^-camphene hydrochloride. Both 

 «- and ^-camphene hydrochloride behave after the manner of tertiary 

 terpene hydrochlorides, for which reason they cannot be direct derivatives 

 of the two secondary alcohols borneol and isobomeol. Aschan was able 

 to prove that both hydrochlorides are derived from the same camphene. 

 In order to establish this, he converted terecamphene (prepared from the 

 hydrochloride of American turpentine oil by heating with bases) into its 

 hydrochloride and recovered camphene hydrate from the latter. When 

 treated with glacial acetic acid this camphene hydrate yielded camphene, 

 which again produced the original hydrochloride of the same rotation. 

 It would therefore appear that the conversion of camphene into the hydro- 

 chloride and into camphene hydrate and vice versa, is accomplished 

 without transposition of the carbon-skeleton. The camphene produced 

 from ^-camphene hydrochloride also gave almost the same rotation as 

 did the fundamental substance, and it is therefore very probable that the 

 fundamental substance was a uniform body. The same results were 

 observed with a camphene of high rotatory power from Siberian pine 

 needle oil. 



Aschan has not succeeded in separating a- and /^-camphene hydro- 

 chloride. Occasionally, but not always, it was possible to purify the 

 ^-derivative by recrystallising it from light petroleum (m. p. 150 to 151°; 

 the highly-active modification melts at 157 to 158°). The behaviour of 

 the crude hydrochlorides towards seminormal alkali-liquor at 50° enabled 

 a quantitative estimate of the constituents to be made. From time to 

 time samples were drawn from the solutions in order to control the con- 

 sumption of potash liquor according to the equation C10H17CI + KOH 

 = CioHie -f KG + H 2 0. The examination showed the camphene hydro- 

 chloride content of the crude isobornyl chloride to be from 60 to 70°/o. 

 Pinene hydrochloride, after frequent recrystallisation, also contains about 

 10°/ of a readily-decomposing hydrochloride which may perhaps consist 

 of a mixture of a- and /^-camphene hydrochloride. Unfortunately, con- 

 siderations of space prevent us from going into the experimental details 

 of this interesting investigation, for which we must refer to the original 

 paper. 



