_Orris root, oil of_ (_oleum iridis_), is obtained by distillation with steam from the rhizomes of _Iris florentina_, which is cultivated in Southern France, Dalmatia, and other regions. It has a yellow color and, at an ordinary temperature, a quite solid consistency like butter or wax, so that it can be rendered fluid only by heating. It consists chiefly of a rigid odorless body to which the liquid odoriferous oil adheres. The solid portion was formerly designated orris-stearoptene; according to Flueckiger it is, however, myristic acid. Oil of orris root is one of the oils which keep for years without suffering injury. It is recommended to keep it in stock in alcoholic solution so that the myristic acid contained in it may to a certain degree be etherized, and cannot injuriously affect the odoriferous principle. 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.