Chemistry of Essential Oils

412 THE CHEMISTRY OF ESSENTIAL OILS

HCN....

Equivalent quantity of

cyanohydrin

Gale, quantity of free benzal-

dehyde ....

Estim. by Ripper's method.

Estim. with hydroxylamine.

Estim. with phenylhydra-

zine (Denis and Dunbar's

method) ....

Sample No. 1.

3*6 per cent.

17*6 „

82-4 „

81-3 to 82-1 per

cent.

78 *9 per cent.

83-2 „

Sample No. 2.

2*8 per cent.

—

86-2 per cent.

80 percent.; 81*4

per cent.

83-6 per cent.;

87*2 per cent.

Sample No. 3.

2*4 per cent.

—

88*2 per cent

85-2 per cent.

For an exhaustive examination of the various processes proposed for

the determination of hydrocyanic acid, the reader is referred to a series of

papers by Runne in the Apatheker Zeitung.^1

OIL OF CHERRY LAUREL.

Cherry Laurel Oil is distilled from the leaves of Primus laurocerasus,

an evergreen shrub, a native of South-eastern Europe and Asia Minor.

Most of the oil is distilled in the south of Switzerland and in Italy. It

is obtained also in England and Germany, together with the official

cherry laurel water, by distilling the leaves in the ordinary way. It has

the following characters:—

Specific gravity 1'050 to 1-066

Optical rotation + 0° 12' „ - 0

°

46'

Refractive index 1-5400 „ 1-5440

It contains benzaldehyde, prussic acid, benzaldehyde-cyanhydrin, and

possibly traces of benzyl alcohol, and, indeed, differs very little from oil

of bitter almonds.

OIL OF WILD CHERRY BARK.

The bark of Prunus virginiana yields about *2 per cent, of essential

oil of specific gravity about T050, and optically inactive. It closely re-

sembles oil of bitter almonds.

OIL OF MEADOW SWEET.

This oil is obtained by the distillation of the flowers of Spiraea Ul-

maria, which yield about 0*25 per cent, of oil.

It contains salicylic aldehyde, C 6 H 4 (OH)(COH), a terpene, methyl

saliglate, vanillin, and hetrotropin.

CALYCANTHACEJC.
OIL OF CALYCANTHUS.
Scalione^2 has examined the essential oil of Butneria occidentalis, or
Calycanthus occidentalis, which he obtained to the extent of 0-27 per cent,
of the leaves and twigs. The oil had the following characters:—

lApotheker Zeitung, 24 (1900), 288, 297, 306, 314, 325, 333, 344, 356.

* Jour. Ind. Eng. Chem., 1916, 729.