SCIENTIFIC NOTES ON ESSENTIAL OILS. 15 
the semicarbazone of the copaene ketonic acid methylester melted at 193,5 to 194°. 
Oxidation of the copaene ketonic acid with alkaline bromine solution led to a dicarboxylic 
acid Ci.HisOx, copaene dicarboxylic acid, the methyl ester of which boiled at 178 to 
182° (14 mm.). 3 
The authors presume that, judging from its chemical nature, copaene belongs to 
a new type of tricyclic sesquiterpenes, as by the addition of hydrogen chloride it 
readily passes into the type of cadinene. The latter is bicyclic and is probably based 
on a hydrogenated naphthalene nucleus. 
J. D. Riedel, Berlin’), describes a balsam of copaiba originating from Manaos, the 
capital of the Brazilian province of Amazonas. dis0 0,930; «) —40°; acid v. 23,8; 
sap. v. 42,1. This balsam yielded about 80 p.c. of an oil which rotated ap — 35° 20° 
The optical rotation of the resin left after distillation, determined in chloroform solution, 
- was about — 55°, calculated on pure resin in 100 mm. thickness. 
At the same time Riedel examined several other balsams of copaiba of different origin. 
Maracaibo balsams rotated from + 24 to + 30°, the oils obtained therefrom showed 
— 6 to -—13°, and the resinous distillation-residue (about 65 p.c.) showed -+ 40 to + 60°. 
A sample of Maturin balsam showed a rotation of @p + 35°, the corresponding oil a)—9°, 
and the residual resin (about 57 p.c.) about +70°. African balsam showed ep -+ 1°20’, 
the oil obtained from it «)-+ 27° 20’ arfd the residual resin (about 51 p.c.) about — 23°. 
We too had occasion to examine Manaos balsams several times of late. One 
sample showed the following constants: dis0 0,9280; a) — 29° 30’; npw»o0 1,50457; acid v. 
- 23,2; ester v. 5,5; the oil drawn from it (yield about 81 p.c.) diso 0,9036; oe —32° 28’; 
 Mpmo 1,50092; acid v. 0,6; ester v. 6,4. Two further distillates of Manaos balsams had 
the following properties: diso 0,9068 and 0,9095; a) —16°4’ and —30° 6’; npmo0 1,50045 
and 1,53012; acid v. of both 0,3; ester v. 3,7 and 0,9, both soluble in 6 volumes and 
more of 95 p.c. alcohol. The yield of oil was 83,4 p.c. in one instance, and 79,6 p.c. 
in the other. 
Costus root Oil. F.W.Semmler and J. Feldstein?) report on the examination of 
a costus root oil supplied by ourselves, for which they established the following 
figures: b. p. 60 to 215° (11 mm.); d230,9851; «p+ 15°24’; np 1,51264. In a fraction 
of the b. p. 200 to 210° (11 mm.) (deio 1,0749; @p + 38°; np 1,53103) a lactone Cis Hoo Oz 
was proved, which, for purification, was converted into the corresponding hydroxy 
acid, the methyl ester of which reconverted into the lactone on boiling. The authors. 
call the body costolactone. It boiled at 205 to 211° (13 mm.); de1o 1,0891; ap + 28°; 
Np 1,53043; molecular refraction calculated for Cis;H29O2/z 65,91, found 65,85. Costo- 
lactone is bicyclic and diolefinic. 
A fraction of the b. p. 190 to 200° (11 mm.) (deio 1,0501; %) + 44°; np 1,52703) 
contained a diolefinic bicyclic acid CisH22O:, i.e. costic acid, which after purification 
over its silver salt showed the following properties: b. p. 200 to 205° (11 mm.); 
dero 11,0508; 4) + 40°; np1,51912; molecular refraction calculated for CisHe2O2/2 67,85,. 
found 67,73. The methyl ester boiled at 170 to 175° (11 mm.). 
The same fraction contained a lactone Cy;H22O2, which the authors call dihydro- 
costolactone. The silver salt of the corresponding hydroxy-acid was converted into 
its methyl ester which, upon distillation in vacuo, returned dihydrocostolactone. Thus 
purified it showed: b. p. 210 to 213° (19 mm.); do20 1,0776; ep) + 48°; np 1,52289; 
1) Riedels Berichte und Mentor, 1914, 27. — 7%) Berl. Berichte 47 (1914), 2433, 2687. 
