— 73 — 



to 159°, di 5 o 0,8638, « D — 1°12\ The nitrosochloride, of which a liberal 

 yield was obtained by the action of nitrosylchloride, melted at 109 to 110° 

 and the benzylamine compound at 123 to 124°. We were unable to 

 identify ^-pinene either in this or in the other fractions, but we succeeded 

 in proving the presence of camphene. 



The fraction in question boiled at 161°, and possessed the following 

 constants: di 50 0,8697, « D +2°32\ The isoborneol, prepared by reduction 

 according to Bertram and Walbaum's method, melted, in spite of repeated 

 recrystallisation from light petroleum, only at 205 to 206°: [«] — 6° 28' in a 

 17,8°/o alcoholic solution. Closer examination showed it to consist of a 

 mixture of borneol and isobomeol. In order to determine the quantity of 

 rsoborneol present we converted it into the methyl ether and ascertained 

 the methyl-value by the familiar method, when it was found that the mix- 

 ture of alcohols obtained by hydration consisted only to the extent of 

 about 50°/o of isobomeol. Borneol was easily detected by Tchugaeffs 

 nitric acid test 1 ). By applying A. Hesse's modification* 2 ) of Bertram and 

 Walbaum's methyl ether reaction it was also possible to establish the 

 presence of borneol. Hence it follows that the camphene of juniper berry 

 oil yields a mixture of borneol and isoborneol. 



We have on repeated occasions, by hydrating terpene -fractions in 

 which the presence of camphene was proved by Bertram and Walbaum's 

 reaction, obtained isoborneols of which the melting points, in spite of 

 repeated recrystallisation, could not be raised above 205 to 206°, as, for 

 instance, in the case of oils of lemon 3 ), cypress 4 ), and myrtle 5 ). On the 

 other hand, however, the hydration of camphene from citronella oil 6 ) and 

 kesso oil 7 ) readily yields isoborneol melting at 211 to 212°. We will not 

 venture to decide whether a sufficient explanation of this problem is to 

 be found in the opinion expressed by Aschan 8 ) on the occasion of an 

 examination of santene from Siberian pine-needle oil, to the effect that 

 camphene, in addition to isoborneol, always yields borneol. But it is a 

 remarkable fact that whereas the one camphene produces almost exclus- 

 ively fsoborneol, the other yields borneol and isobomeol in almost equal 

 proportions, and the thought occurs that this difference in behaviour may 

 perhaps be caused by the presence of different hydrocarbons, or possibly 

 camphenes. 



x ) Chem. Ztg. 26 (1902), 1224. 



2 ) Berl. Berichte 39 (1906), 1127; Report October 1906, 112. 



5 ) Report October 1903, 33. 



*) Report April 1904, 39. 



r >) Report April 1907, 73. 



*) Report October 1893, 15. 



'<) Bertram and Walbaum, Journ. f. prakt. Chem. II. 49 (1894), 118. 



h ) Berl. Berichte 41 (1908), 130; Report April 1908, 85. 



