Chemistry of Essential Oils

LABIAT-ZE 255

and had a specific gravity O9335 and an optical rotation - 58° 45'.
This latter fraction yielded a sesquiterpene of specific gravity 0*930,
optical rotation + 0° 45', and boiling-point 273° to 274° at 760 mm.
According to Schimmel & Co.
1
about 97 per cent, of patchouli oil
consists of bodies of no value for odour purposes. They have detected
the following constituents in patchouli oil: benzaldehyde; eugenol;
cinnamic aldehyde; a terpenic alcohol of rose-like odour and of un-
determined constitution; a ketone of caraway odour forming a semi-
carbazone melting at 134° to 135°; and a base of stupefying odour not
yet identified. But as all these bodies are present in traces only it
•cannot be said that our knowledge of the odour bearers present in
patchouli oil is complete.
Simmons^2 records two samples of commercial oil to which some
artificial ester, or oil containing a high proportion of esters, had been
added. These two samples had the following characters:—

1. 
   
   
   
   2. Specific gravity 0-9948 0'9937Rotation
      Refractive index
      Aciditytrace
      Ester value 5818
      Solubility in 90 per cent, alcohol
   
   
   
   

- 38° 30' - 49" 30'

1-5175 1-5110

trace trace

58 18-5

1 in 0'75 1 in 0'5

MELISSA OIL.

True melissa oil, or oil of balm, is the distillate of the herb Melissa
cfficinalis, a plant indigenous to the Northern Mediterranean littoral and
Western Asia. It is also cultivated in North America. The leaves have
an odour recalling that of a mixture of lemon grass and citronella. The
yield of oil is, however, so small that the melissa oil of commerce is
practically invariably the result of the distillation of lemon oil with a
little citronella oil (or citronella1) over the leaves of the plant.
Schimmel & Co.^3 have examined the pure oil, distilled from the
fresh herb,and found two oils to have the following characters :—
From Fresh Herb
at Commencement
of Flowering.
Yield 0-014 per cent. 0*104 per cent.
Specific gravity .... 0-924 0-894
Rotation + 0° 30' +0°
The oil contains citral, and probably a little citronellal. Flatau and
Labbe 4 state that a sample examined by them contained the following :—
Geraniol 20 per cent.
Linalol 12 „
Oitronellol 6 ,,

OIL OF SAGE.

Sage oil is obtained from the herb Salvia officinalis, a plant indi-
genous to the Northern Mediterranean littoral. The oil is distilled to a
considerable extent in Dalmatia, and recently a fair amount of oil has
been manufactured in Spain but from a different species of Salvia. The
leaves and twigs of the plant yield from 1 to 3 per cent, of oil. A cer-
tain amount of oil is also distilled in Germany.

1

Report, April, 1904, 68. * Chemist and Druggist (1904), 815.

»Bericht, October, 1894, 37. 4 Bull. Soc. Chim. (1898), ii. 636.