A practical treatise on the manufacture of perfumery

by C. Deite

Oil of orris root serves as a substitute and for strengthening the natural odor of violets. It can, however, be employed only for very fine expensive perfumery since, on account of the very slight yield from the root (from 1000 parts ½ to ¾ part of oil), its price is very high, generally exceeding that of rose oil.

An admixture of other volatile oils of less value would render the oil fluid at the ordinary temperature.

Patchouli oil.—By the name of patchouli are known, according to L. Wray, Jr., the leaves of Pogostemon patchouli, Pellet, natural order Labiatæ, indigenous to the East Indies, and known and used for centuries in the various regions of China, Assam, and the Malayan Islands. Most of the patchouli comes from the East Indies. Before exportation it is sorted into three qualities: 1. Selected, consisting of leaves only. 2. Mixed, leaves with slight peduncles and few stems. 3. Stalky leaves. The best quality occurs seldom in commerce since the picking of the leaves does not cover the expense.

According to Wray, the leaves are intentionally mixed with those of the ruku (ocimum basilicum, L.), an herb indigenous to the Malayan Islands. The leaves of the latter are broader than those of pogostemon patchouli, and the stalks thinner and round. Seed-capsules are also frequently found among the leaves, though patchouli seldom flowers and bears seeds.

In Europe, patchouli has been an article of commerce since 1841. In the Orient it is highly esteemed as a perfume. The Arabs even ascribe remedial properties to it, and it is customary with them to fill their pillows with the leaves to protect them from infection and prolong their lives.

The peculiar, penetrating, though not exactly agreeable, odor of patchouli leaves, is due to a volatile oil, of which they contain 1.5 to 2 per cent. In the Orient this oil has for many years been obtained by distillation.

In the Penang market two kinds of oil, one green and the other gold-brown, are distinguished. Though both are sold at the same price, there is a greater demand for the green oil. According to the statements of the distillers, the brown oil is derived from the leaves of old plants and the green oil from the leaves of young plants. It would seem, however, that the color is dependent on the soil upon which the plants are grown, as well as upon atmospheric influences. When ruku is distilled with patchouli leaves, the oil is yellow and thickly-fluid.

In Germany, the oil is now distilled from imported leaves. It is thickly-fluid, of a brown color, and, in an undiluted state, possesses a disagreeable, almost musty odor. However, when sufficiently diluted and suitably mixed with other volatile oils, the odor is far more agreeable, and for this reason it has for some time played an important part in the manufacture of perfumery. It has the advantage of being very yielding and lasting, but, on the other hand, possesses the disadvantage of not combining with other perfumes, so that its odor is always perceptible. It should always be used in very small quantities or much diluted.

In commerce Penang oil and French oil are distinguished, the first having a specific gravity of 0.959 and the latter of 1.012. When kept for any length of time the oil deposits patchouli-camphor (C₁₅H₂₈O) in prismatic crystals of 1.045 specific gravity and melting at 127 to 129° F. These crystals have a peculiar, very lasting odor.