DIPTEKOCABPACE^E 529
identified pinene and caryophyllene in it. The specific gravity of the oil
ranges from -920 to *935 and the optical rotation from + 1° to + 3°.OIL OF WABBUBGIA.
The wood of Warburgia stuhlmanni, a Zanzibar tree, yields about
0*6 per cent, of essential oil, having an odour recalling that of sandal-
wood oil. Its characters are as follows :—-^1
Specific gravity 0-9864 at 20°
Refractive index....1-5127
Optical rotation....- 41-77°
Saponification value .... 11-2
„ (after acetylation) .... 100*3
The oil contains aldehydes and (sesquiterpene ?) alcohols, together
with esters and traces of free acids.DIPTEROCARPACEjE.OIL OF BORNEO CAMPHOK.The wood of Dryobalanops aromatica, or Borneo camphor tree, yields
this essential oil. The tree is a native of Sumatra and North-West
Borneo, but its essential oil is rarely seen in commerce.
It has the following characters :—
Specific gravity. 0-9180
Optical rotation.•.+ 11° 5
Refractive index.1-48847
Acid value .... 5-6
Ester „ ....0
,, „ (after acetylation). 50-5
The oil contains a-pinene, camp!lene d-borneol, 0pinene, dipentener
terpineol, and sesquiterpenes.
Schimmel & Co.^2 have investigated the oil with the following results.
The terpenes have the following characters:—
Boiling-point 155° to 156°
Specific gravity '. 08631
Optical rotation + 7
°
32'
Refractive index 1-46668
These figures indicate the presence of a-pinene.
A fraction posssssing the boiling-point of camphene gave the following
figures: d^0 08639; aD + 5°37'. On hydration with glacial acetic-sulphuric
acid it afforded a large proportion of ^soborneol, but in spite of repeated
purifications from light petroleum the melting-point of the last-named
body remained as low as about 208°. Small quantities of /3-pinene were
found in a fraction possessing the following physical properties : boiling-
point 163° to 167°; duo 0 8607; aD - 0° 20'; ND. 20 ° 1-47102. When treated
with permanganate and alkali it yielded in the form of an oxidation-
product the characteristic leaflets of sodium nopinate, from which nopinic
acid, melting-point 124° to 126°, was obtained. Oxidation of the sodium
salt with permanganate in acid solution afforded nopinone, of which the
semi-carbazone had melting-point 186° to 188°.
^-Borneol was found to occur in the following fraction, which distilled
between 55° and 85° (5 mm.). When fractionated once more it congealed
in the condenser. Filtered by suction the crude product, when tested
1
Ber. Pharm. (1910), 20, 351.
2
Report, April, 1913, 33.
VOL. I. 34