THE CITRINE ODOURS. 77 
a green homogeneous mass, and not exceed six per cent. (except 
in very recent specimens) *. 
According to recent researches of Schimmel and Co.+, the most 
important constituent of bergamot oil (to the extent of 40 per cent.) 
is the acetic ester of Linalool, a body which is also contained in 
oil of lavender (which see). Linalool, discovered by Semmler ff, 
forms the principal constituent of Mexican Linaloe oil (which see). 
The crystalline constituent of Bergamot oil, Bergapten, C,.H;O,, 
has recently been studied by Pomeranz§. Its melting-point is 
188° C. 
The odour of Bergamot has been noticed in the chloride of 
sylvestrene :— 
Sylvestrene.—Stockholm tar and Archangel tar are obtained in 
the North of Europe by the dry distillation of fir-wood (Pinus 
sylvestris and P. Ledebourii), and these are the source of both 
Swedish and Russian turpentine. The former was found by 
Atterberg to contain both australene and sylvestrene, which are 
stated by Tilden || to be also present in Russian turpentine, while 
Wallach has observed the occurrence of Dipentene in addition to 
these. 
Sylvestrene, Cj)H,., boils at 173-175°, and smells like fresh 
fir-wood. The chloride is formed by passing hydrochloric acid 
into its ethereal solution, and yields the pure hydrocarbon on 
heating with aniline, or, better, with sodium acetate and glacial 
* Schimmel and Co., Report, April 1891. 
To determine the solubility of an oil in alcohol, 2 ¢. c. of it are placed in a 
stoppered bottle, and the alcohol is gradually added from a burette, the mixture 
being well shaken after each addition. The termination of the experiment is 
known by the liquid becoming clear. A suspected sample being now similarly 
treated, it will be found that if turpentine be present a larger proportion of 
alcohol will be required. It must be borne in mind that some other oils, such 
as those of juniper, savin, eucalyptus, and copaiba, are but slightly soluble in 
dilute alcohol, and that they may, when mixed with other oils, give rise to 
appearances similar to those produced by oil of turpentine. Moreover, in some 
cases, changes take place in oils which have been kept for a long time, and these 
must be considered in applying the alcohol test for turpentine. A test for 
alcohol in essential oils is the red coloration produced, if alcohol be present, 
when a drop of the oil is let fall on a crystal of “ magenta.” To some oils, such 
as clove, however, this test does not apply. 
t Tbid. April 1892. t Ber. Deutsche chem, Ges. 1891, xxiv. p. 207. 
§ Monatshefte fiir Chemie, 1891, p. 379. 
|| Journ. Chem, Soc. xxxiii, p. 80. 
