Sex. Syst. Triandria, Digynia.
According to Dr. Royle, [Essay on the Antiquity of Hindoo Medicine, pp. 33 and 82,1837; and Illustrations of the Botany, &c. of the Himalayan Mountains, p. 425, 1839.] the grass-oil of Nemaur is obtained from a new species of Andropogon, to which he has given the name of A. Calamus aromaticus. He says that it is "found in Central India, extends north as far as Delhi, and south to between Godavery and Nagpore, where, according to Dr. Malcolmson, it is called spear-grass: it may be the A. Martini of Roxburgh, as I believe, it is also thought to be by Dr. Wight, though it has been named A. Nardoides by Nees von Esenbeck." Dr. Royle examined Mr. Hatchett's specimens of the grass, obtained from Mr. Swinton, as the source of the grass-oil, and found them to be identical with his A. Calamus aromaticus, though Mr. Hatchett's figure of the plant (copied from the Phil. Trans, vol. lxxx.) actually represents another species, viz., A. Iwaruncusa. Dr. Wallich [Transactions of the Medical and Physical Society of Calcutta, vol. i. p. 368, Calcutta, 1825.] examined a specimen of the plant from which the grass oil is obtained, and declared it to be either A. Iwarancusa, or, perhaps, A. Martini, Roxburgh.
Dr. Royle [In Kitto's Cyclopaedia of Biblical Literature, vol. ii. p. 105, 1845.] considers this species to be the sweet calamus [Exodus, ch. xxx. ver. 23. It is here called Kaneh Bosem, literally reed offragrance.] and sweet cane [Jeremiah, ch. vi. ver. 20 It is here denominated Kaneh Hattob, or good reed.] of Scripture—the καλαμος αροματικος of the ancient Greeks. [Dioscorides, lib. i. cap. 17.]
Grass-oil of Nemaur; Roosa-ke-tel, Hind.; Oleum graminis Indici.—This oil is imported from India under the name of grass-oil or ginger-grass oil. [Ainslie (Mat. Indica, vol. ii. p. 401) applies the names of ginger-grass, spice-grass, false spikenard, sukkunaro-pilloo (Tamool), to the Andropogon Nardus (?) of Dr. Rottler, which he says is common in the Cautalum hills and in the Tinnevilly district; but he puts a query whether it may not be the fragrant grass described by Mr. Maxwell in the Transactions of the Medical Society of Calcutta, vol. i. p. 367, 1825.]
In 1845, I obtained from a merchant in London a sample of essential oil which agreed in its sensible qualities with the grass-oil of Nemaur given me by Dr. Royle. With it I received the following notice: "A sample of three canisters of essential oil imported from Bombay, under the name of ginger-grass oil, and, according to the importer, used by the natives against rheumatism, and by them called rosa oil. The grass grows, according to the same authority, fifty or sixty miles from Bombay in the jungle, and is there called rosa grass. It smells, as you will perceive, of ginger and turpentine."
Grass-oil of Nemaur is commonly known to the perfumers by the name of oil of geranium. I have been informed that it is sometimes called oil of rose geranium. It is occasionally sold by druggists as oil of spikenard.
Under the name of "Ol. Palm. ros," [sic] a volatile oil has been sent from a merchant in Constantinople to his correspondent in London, as an oil used for reducing (that is, adulterating) otto of roses; and, in the accompanying letter, it was stated that if genuine otto be mixed with from 20 to 30 per cent. of this oil, it would be still equal to the finest commercial otto. By the dealers in London this oil was called oil of geranium. [Reeluz (Journ. de Pharm, t. xiii. p. 529, 1827) obtained from Pelargonium odoratissimum, var. odore rosato (Persoon), a concrete volatile oil, which he calls volatile oil of geranium with the odour of the roses (huile volatile du Géranium à odeur de roses). It must not be confounded with the so-called oil of geranium alluded to in the text.] It is almost colourless, and is clearer, brighter, and more fragrant and roseate than ordinary grass-oil; but its odour is, I think, essentially that of the latter. Is it rectified grass-oil? It is remarkable that Dioscorides (lib. i. cap. xvi.) states that ςχανος (a native of Arabia) has the odour of the rose.
Grass oil of Nemaur is, according to Mr. Forsyth, [Transactions of the Medical and Physical Society of Calcutta, vol. lii, p. 213. Calcutta, 1827.] procured at the foot of the Vindhya range of hills in the vicinity of Jaum Ghat, and thirty miles further west, near Nalcha.
It is obtained by distillation. When the plant begins to flower, it is cut and bound in small bundles or maniples, 250 or 300 of which are introduced into a wrought-iron boiler fitted over an earthen fireplace. Water being added, ebullition is promoted. The oil, with water, distils over into two large copper receivers immersed in cold water. The process occupies about six hours. After the product has stood for some time, the oil is skimmed off the surface by a small shallow spoon.
Commercial grass-oil of Nemaur is of a light straw colour, and has a fragrant aromatic roseate odour, with taste which is not very dissimilar to that of oil of lemons. It floats on water. Dr. Stenhouse [Memoirs and Proceedings of the Chemien! Society of London, vol. ii. p. 122, 1845.] found that it is usually a mixture of a pure volatile oil (C4H3), and of about half its bulk of a fluid resin, the latter probably being the product of the oxidation of the oil.
In India, the grass-oil is frequently adulterated; usually, according to Mr. Forsyth, with the ol. sesami. As this is a fixed oil, the sophistication is readily detected by dropping the suspected grass-oil into rectified spirit: if pure, it dissolves, but if it be mixed with a fixed oil, the spirit becomes milky.
Grass-oil is chiefly employed in perfumery; but it is also employed in medicine. Its medicinal properties are similar to those of other aromatic fragrant volatile oils, and are those of a stimulant and diaphoretic. It is highly esteemed in India for the cure of the more chronic forms of rheumatism. It is applied as a liniment. A couple of drachms of it are rubbed into the affected part in the heat of the sun, or before the fire, twice daily. It causes a sense of warmth and pricking which lasts for two hours or longer. It is also employed to excite diaphoresis in slight catarrhal affections; and for this purpose it is rubbed into the soles of the feet and wrists.