oe : * Am. Four. Phar., 1885, 600, a Peppermint Camphor. 
416-4 
PART USED AND PREPARATION.—The whole fresh, flowering plant Is 
chopped and pounded to a pulp and weighed. Then two parts by weight of alco- 
hol are taken, the pulp mixed thoroughly with one-sixth part of it, and the rest 
of the alcohol added. After stirring the whole well, and pouring it into a well- 
stoppered bottle, it is allowed to stand eight days in a dark, cool place. 
The tincture, separated from this mass by pressure and filtration, should have 
a clear orange-brown color by transmitted light; retain the odor of the plant; 
have an oily feel; a bitterish, slightly astringent, mint-like taste; and an acid 
reaction. : 
CHEMICAL CONSTITUENTS.— Oi/ of Peppermint. This essential oil of the 
leaves is either colorless, pale yellow, or greenish, turning brown with age. It is 
liquid, has a sp. gr. of 0.84-0.92, boils at 188°-193° (370.4°-379.4° F.), has a strong, 
agreeable odor, and a powerful aromatic taste, at first biting, then cold, especially 
upon strong inhalation of air over the tongue; this effect is followed by a peculiar 
numbness characteristic of this product. The oil is soluble in water and in alcohol. 
It consists of a solid and liquid portion, and contains from 0.5 to 5 per cent. of 
a hydrocarbon (C,,H,,-+ or—O), which is said to prevent the crystallization of 
menthol. 
The oil of commerce is often adulterated with that of pennyroyal, with intent, 
or that of Mentha arvensis, Evigeron Canadense, or Erechthites hieractfolia, by 
carelessness. The tests for the oil are given by the Or/ and Drug News as fol- 
lows: On the addition to the oil of an equal part of a mixture of two parts chloral- 
hydrate, dissolved in one part of C. P. sulphuric acid and a drop or two of alcohol, 
a cherry-red coloration follows if the oil is pure; but, if pennyroyal is present, a 
dark olive-green color ensues; and D. Reagan says* that the pure oil is but slowly 
absorbed by blotting paper, but when the three plants above mentioned are mixed 
with it the absorption is rapid. 
If the presence of the hydrocarbon above mentioned is very slight, the oil 
cooled to — 4 (+ 24. 8° F.) will deposit. 
Pipmenthol, C,,H,,O, a stearopten of the exquisite odor of Peppermint, com- 
posed of fine hexagonal crystals, melting at 36° (96.8° F.), and boiling at 210° 
(410° F.).t 
[Menthol—Under this name is understood the Chinese Oil of Peppermint, 
which is distilled from Mentha Favanica, B\., which is so pure that it almost wholly 
_ yields this product. Chinese menthol is very like that of other countries, but differs 
essentially in melting at 42° (107.6° F.), and boiling at 212° (413.6° F.). The 
import of this substance in 1884 was 4000 lbs., since when it has greatly increased. ] 
Menthene, C,,H,,—On distilling menthol with phosphorous pentoxide, this 
body results as a levogyrate liquid, boiling at 163° (325.4° F.). 
An almost odorless resin, and tannin, have also been determined. 
{ Henry Trimble, 4m. Four. Phar., 1883, 486. 
