Chemistry of Essential Oils

LABIATE 233

Oil from

Specific Gravity

at 20°.

One year old Plants

Two

0-912

0-913

Rotation.

• 17° 42'


• 17° 57'

Acid Value.

0-57

0-56

The menthol values of the two oils are as follows: One year old

plants, 42*44 per cent, free menthol, 49*17 per cent, total menthol; two

year old plants, 41*33 per cent, free menthol, 50*07 per cent, total

menthol.

One hundred grams of the two year old plant oil has fractionated

with the following results :—

Distilled at Per Cent.

To 200° 9-5,

200° to 205°

205° ,

210° ,

215° ,

220° ,

225° ,

230° ,

Above

, 210°

, 215°

, 220°

, 225°

, 230°

, 235°

235°

8-0

8-0

17-5

21-0

5 5

7-0

4-5

18*0

Maisit considers that a sesquiterpene is present in the high boiling

fractions.

-. Those districts known as the Ukraine (

u

Little " Eussia and Euthenia)

are exceptionally favourable to the growth of peppermint, and somewhere

about 20,000 Ib. of oil are distilled here every year, and the output is

increasing. A sample of this oil examined by Umney l had the following

characters:—

Specific gravity 0-904

Optical rotation - 26°

Total menthol.53-8 per cent.

Menthyl acetate ........ 6 ,,

It was soluble in 3 volumes of 70 per cent, alcohol.

Eussian peppermint oil will usually have values falling within the

following limits:—

Specific gravity.0-903 to 0-920

Optical rotation.'- 15° „ - 28°

Menthol as esters 3 to 10 per cent.

Total menthol.50 „ 60 „

In addition to menthol and menthyl esters, this oil contains men-

thone, principally in the dextro-rotatory form, Z-limonene, dipentene,

inactive a-pinene, and cineol. The esters are present as acetate and

isovalerianate.

A small amount of
plantations existing in
characters:—

GBEMAN PEPPERMINT OIL.

peppermint oil is distilled in Germany, successful

Saxony especially. German oil has the following

J P. and E.O

M. (1914), 314.