Chemistry of Essential Oils

396 THE CHEMISTRY OF ESSENTIAL OILS

FRENCH OTTO OF EOSE.

In France numerous different roses are distilled, each yielding its

own characteristic otto, so that the resulting products will vary according

to the percentage of each given rose in the distilling material.

In 1904 Jeancard and Satie^1 published a paper dealing with the

analysis of otto of rose. They distilled a sample from the sepals only of

Eosa centifolia, and found it to have the following characters :—

Congealing-point.

Stearoptene.

Specific gravity

Rotation.

Melting-j^oint of siearoptene

Acid value

Ester „ ...

Total alcohols

Citronellol

51*13 percent.

0-8704 at 15°

• 41°
  14°
  6-12
  16-28
  1399 per cent.
  13-56
  This sample, as will be observed, contained practically no geraniol,
  the alcoholic constituents consisting entirely of citronellol.
  An oil distilled from the whole flowers, on the other hand, had^the
  following characters:—
  Specific gravity 0-879 at 15°
  Rotation. - 3°
  Alcohols.88-5 per cent.
  Citronellol 22-4 „
  Congealing-point.. .' 25-5°
  Stearoptene 322 per cent.
  A similar oil, distilled without cohobation of the distillation waters,
  and so distilled that 1 kilogram of roses gave 1 litre of rose water, had
  the following quite different characters :—

Congealing-point 25-9°

Acid valueStearoptene.

Ester „

Total alcohols

Citronellol

58-88 per cent.
2-24
14-70
32 per cent.
15-10 per cent.
Dupont and Guerlain,
2
have found samples of French otto of rose to
have specific gravities varying between O8225 and 0*8407 at 30°, optical
rotations from - 6° 45' to - 8° 3', and stearoptene-content from 26 to 35
per cent.
An authentic otto distilled from tea-roses only was found to contain
72 to 74 per cent, of Stearoptene.
Two analysis of ofcto from the rose d'hai have been published by
Schimmel & Co. The figures are as follows:—

2.

0-8653

• 3° 20'
  1-46159
  18-6°
  1-8
  5-6
  91-8 per cent.
  As a matter of fact, the total alcohols in this particular type of otto
  consist almost entirely of geraniol, and are nearly free from citronellol.

Specific gravity at 30°

Rotation.

Refractive index at 25°

Melting-point.

Acid value

Ester „

Total alcohols

1.

0*8706

- 1° 26'

1-46486

13°

1-8

6-3

91 per cent.

(^1) Bull. Soc. Chem. de Paris (1904), 934. * Comptes rendus, 123 (1896), 700.