Oleum Geranii. - Geranium- or Pelargoniumol. - Essence de Geranium Rose.
Origin. For the purpose of distillation three species of the genus Pelargonium and their cultural varieties are principally cultivated, viz., Pelargonium odoratissimum, Willd.1), P. capi-tatum, Ait., and P. roseum, Willd. (family Geraniaceae). The last-named is regarded as a variety of P. Radula, Ait.2). According to L. Ducellier3), Pelargonium graveolens, Ait. (P. tere-binthinaceum, Cav.) is cultivated exclusively for the distillation of the volatile oil.
1) Pharm. Zentralh. 40 (1899), 533.
2) W. G. Boorsma, Uber Aloeholz und andre Riechholzer. Bull, du Dep. de l'Agricult. aux Indes Neerl. 1907 No. 7 (Pharmacologic III), p. 25; Report of Schimmel & Co. October 1908, 21.
3) Jaarb. dep. Landb. in Ned.-Indie, Batavia 1906, 45; Report of Schimmel & Co. October 1908, 49.
The oil is located principally in the leaves, stems and petioles being devoid of oil which is likewise wanting in the flowers of P. odoratissimum 4), whereas, according to Blandini5), the oil content of the flowers is greater than that of the leaves. As a rule, however, the leaves only are used in the production of oil. The harvest begins shortly before the flowering period when the leaves begin to turn yellow and when the lemon-like odor gives way to the rose-like odor.
The plants grown on dry soil are said to give less oil, but an oil of finer quality than those cultivated on soil that is irrigated.
The reports found in literature as to the yield of oil vary considerably. In France the leaves of P. odoratissimum yield 0,16) to 0,2 p.c.4), in Corsica 0,125 to 0,166 p.c.7). In Reunion where P. capitatum is cultivated, the leaves of this species yield 0,1 to 0,14 p.c.8) of oil. The distillation conducted in Italy (Portici) on an experimental scale, yielded much higher results: the leaves yielded 0,7 to 0,8 p.c. and the flowers 1,5 to 1,98 p.c.5). In Sicily but 0,07 p. c. of oil were obtained.
1) According to the Index Kewensis P. odoratissimum (Sol.) Ait.
2 ). C. Sawer, Odorographia. London 1892, vol. I, p. 42.
3) The excellent monograph by this author on "Le Geranium rosat, sa culture en Algerie", Algiers 1913, appeared too late to receive consideration in the preparation of this treatise.
5) E. Charabot and G. Laloue, Compt. rend. 136 (1903), 1467.
6) Bull, de I'Office du Gouvern. de l'Algerie 12 (1906), 277; Report of Schimmel & Co. April 1907, 54. - The publication of Blandini, who made his cultural experiments at the agricultural school at Portici, were known to the author only through the abstract referred to above. In as much as his statements concerning the oil yield of leaves and flowers differ materially from those made by other authors, the firm of Schimmel & Co. directed a request for information to this institute. However, no answer was received to the two requests made.
6) Berichte von Roure-Bertrand Fils April 1901, 17.
7) R. Gattefosse, Parfum. moderne 3 (1910), 73.
8) de Cordemoy, Rev. cultures coloniales 14 (1904), 170.
According to J. de Cordemoy1), Pelargonium capitatum, Ait. is cultivated in Reunion. In recent years its cultivation has been considerably increased. Altitudes of from 400 to 1200 m. are selected. In the higher altitudes the winters are too severe, the plants being ruined by frost. A soil rich in humus, such as exists in newly broken ground, is best adapted to the cultivation of rose geranium. For. the production of the oil, the distillers use very simple stills of which about 250 are found in the entire colony. About 700 to 1000 kg. of leaves yield 1 kg. of oil. The exhausted leaves are very serviceable as fertilizer.
In Algiers the oil of rose geranium is mostly distilled in regions surrounding the cities. Boufarik, in the plains of Mitidja, about 35 km. distant from the city of the same name, is the commercial center. The most important factory is reported to be located in an old monastery of the Trappists order.
According to Robert Gattefosse2), the cultivation of rose geranium is still greatly neglected in Corsica. Pelargonium odoratissimum, which grows in northern Corsica, might well be planted successfully in other favorable parts of the island. In May, August and October the working rural population of several communities of the peninsula of Cape Corso is busy with the harvesting and distillation of these fragrant plants.
About half a century ago the cultivation of this plant was introduced from the Provence and was quickly taken up in the communities of Erbalunga, Sisco and Brando. The cultivation is somewhat expensive since the soil requires to be carefully cultivated twice, viz., in March and July, and the irrigation is laborious. In March propagation is accomplished by means of cuttings. For the purpose of harvest the plant is cut off about 5 cm. above the ground. 800 kg. of the first cutting yield 1 kg. of oil; the second is better, only 600 kg. being required; the last cutting yields but little herb and oil. As to quality, the oil is comparable with the Spanish oil and the oil obtained in the vicinity of Grasse.
The annual production amounts to from 600 to 700 kg. However, it has exceeded 1300 kg., but the high price of labor and the low prices offered by the jobbers discouraged the cultivators. The community of Erbalunga owns more than 200 hectares of rose geranium plants which yield, on the average, 5000 kg. of fresh material pro hectare.
1) Rev. cultures coloniales 14 (1904), 170. 2) Parfum. moderne 3 (1910), 73.
Climate, locality and soil seem to impart a special vitality to the plants, since cuttings from the peninsula of Cape Corso are much sought for planting elsewhere. In 1909 more than 350000 cuttings were sold at 15. - francs per thousand.
In France the cultivation of rose geranium (P. odoratissimum) is carried on in the vicinity of Grasse, more particularly in the valley of Laval and in the neighborhood of the two small cities Pegomas and Mandelieu1). The total production of oil amounts to 2000 to 3000 kg.2). Whereas in warmer countries such as Algiers, the plant may survive for from 6 to 8 years and admits of three cuttings annually, in southern France rose geranium must be planted new each year since it is killed by frost. Moreover, but one harvest is possible annually, this taking place between August 20th and the end of September. The plant is propagated by cuttings which are wintered in hot beds and transplanted into the open in March and April3).