Cultivation. The necessary information concerning the botanical origin of the Javanese citronella grass has already been recorded on p. 217. Its cultivation has been discussed by S. Smith'2) who had visited one of the large plantations. If the grass has been planted on good fertile soil and if rain has been abundant, it will grow rapidly and yield a good harvest. Cut four times, the yield is about 4,8 tons per acre. Assuming an oil content of 0,5 p. c, 10 acres will yield 4,8 cwt. of oil at a value of E46 16 s. After a period of 12 years the grass must be replanted.
As in the case of lemongrass3), de Jong4) studied the oil content of Java citronella grass (Sereh wangi) in the different stages of growth in order to ascertain the best time for the distillation of the oil. The result was the same as with lemon grass: the oil content diminishes with the age of the leaf; the sheaths and roots contain much less oil than do the leaves. In this instance also, de Jong regards as the best time for cutting when four to five leaves have developed. Noteworthy is the higher oil content of the citronella grass as compared with lemon-grass, three to four times as much oil being obtained throughout. So far as the properties of the oils, obtained from leaves differing in age, are concerned, the angle of rotation as well as the total geraniol content revealed but slight differences. The optical rotation varies without regularity: values of - 2°7' to - 7°36' were observed for oils from leaves of different age. Passing from the youngest to the oldest leaf, an increase of the total geraniol content is first noticeable, later a reverse: the lowest value observed was 85,5 p. c, the highest 93,3 p. c. The oils examined by de Jong were soluble in three parts of 80 p. c. alcohol. The addition of more than four parts of solvent caused turbidity.
1) Report of Schimmel & Co. October 1905, 20.
2) Agricultural News 5, 335; Kew. Bull. 1906, 363; Report of Schimmel & Co. April 1907, 29. 3) See p. 204. 4) Teysmannia 1908; Report of Schimmel & Co. April 1909, 36.
According to A. j. Ultee1), a various of oil grasses, but particularly citronella grass, have been cultivated in the Botanical Garden of Salatiga (Southeast of Buitenzorg, Java). Inasmuch as Salatiga is located at a much higher altitude than is Buiten-zorg, it seemed desirable to Ultee to ascertain whether this difference in altitude has any effect on the composition of the oil. Upon distillation he obtained 0,66 p. c. of an almost colorless oil which possessed the following constants: d29o 0,8721; aD - 3° 15'; total geraniol 92,75 p. c; soluble in 1,5 vols, and more of 80 p. c. alcohol. This oil differed principally from the Buitenzorg oils by a better solubility. According to de Jong, the latter yielded a clear solution only with three parts of 80 p. c. alcohol, which became turbid again upon the addition of more than four parts of solvent. Inasmuch as Ultee had obtained only 0,66 p. c. of oil whereas the yield in Buitenzorg ranged from 0,5 to 0,9 p. c, experiments were made in Salatiga to ascertain whether the oil content could be increased by fertilizing. Of four experimental fields, three were supplied with different mixtures of artificial l) Cultuurgids, Orgaan van het Algemeen-Proefstation op Java 11 (1909), 404; Report of Schimmel & Co. April 1910, 41.
fertilizer. At the end of 10 weeks the grass was cut and equal amounts from each field distilled in like manner. The yields obtained varied between 0,6 and 0,65 p. c. thus showing that the oil content is not influenced by fertilizers.
The Report of the Royal Botanical Gardens of Ceylon for 1904 contains an interesting communication1) regarding the experimental cultivation of the Maha pangiri variety of citronella grass. From a one acre field, planted in 1902, the following amounts were harvested:
10809 1/4 lbs.
Yield of oil abt. 48 lbs.
,, ,, ,, ,, 36 ,,
19320 1/4 lbs.
Yield of oil abt. 84 lbs.
Hence 1 lb. of pure citronella oil was obtained from an average of 230 lbs. of grass. Another field yielded 16038 lbs. of grass per acre within 6 months, which in turn yielded 60 lbs. of oil. A third field, planted in June, yielded in December 9765 lbs. of fresh grass per acre which in turn yielded 49 1/2 lbs. of oil.
Production. In connection with a trip in the Malay peninsula, made by Carle2) at the request of the "Directeur de 1'Agriculture en Cochinchine" he also made a report on the cultivation of citronella grass (Maha pangiri) and the production of the oil in the district of Johore. The equipment described by Carle was arranged in a shed built on the steep slope of a hill. A boiler that had the capacity to run a 20 horse power engine, furnished the steam for both the still and the pump that supplied the water for condensation. The outfit included two stills each of which had a capacity of 150 kg. of citronella grass. The condenser consisted of a box with a capacity of 2 cbm., the inside of which was lined with zinc. It contained a condensing tube, the lower end of which projected from the side over a Florentine flask which received the oil. Both stills were operated at the same time. The distillation of 300 kg. citronella grass, which lasts about 2 hours, yields about 2 kg. oil = 0,67 p. c. It is estimated that 1 hectare yields annually about 25,000 to 30,000 kg. of citro-nella grass which, in turn, yields 180 to 200 1 of oil. At a price of 3 frs. pro kg., the gross income amounts to from 500 to 600 frs. Deducting 350 to 380 frs. for expenses, 150 to 200 frs. remain as net profit.
1) Report of Schimmel & Co. October 1905, 18.
2) Bulletin de la Chambre d'Agriculture de la Cochinchine 10 (1907), September number, p. 18; Report of Schimmel & Co. April 1908, 32.
Fig. 30. Citronella grass Plantation and Distillery in Java.
Another, somewhat larger distillery within the neighborhood of Singapore was likewise visited by Carle1). The plant was arranged similarly to that in johore. Of stills there were 16 arranged in two batteries, one of which was used exclusively for the distillation of citronella oil, the other for the distillation of patchouli oil. A boiler, sufficient to run a 30 horse power engine, supplied the steam necessary for the alternate operation of the one or other battery, and to run the pump which supplied the condensation water. The capacity of the stills was the same as in johore. The distillation of a charge of 150 kg. also lasted 2 hours. The average yield of citronella oil amounts to 0,65 to 0,7 p. c. The very fertile soil admits of five cuttings annually and yields about 40000 kg. citronella grass (280 1 citronella oil). The cost of cultivation and operation amounts to about 500 frs., hence the net profits are as high as 340 frs.
Composition. The composition of Java citronella oil is similar to that of the Ceylon oil. The principal constituents, citronellal, . geraniol and citronellol, are the same in both2). However, the percentage of these constituents, so important in perfumery, is greater in the Java oil. Hence it possesses a much more intensive odor than does the Ceylon oil. The citronellol of the Java oil is the dextrogyrate modification3). The methyleugenol4) content of the Java oil is very low, amounting to less than 1 p. c, whereas the Ceylon oil contains more than 8 p. c. citra/5) (m. p. of naphthocinchoninic acid 197 to 198°) is also a constituent of the Java citronella oil, being present to the extent of about 0,2 p. c. Whether the hydrocarbons of the two oils are the same has not yet been ascertained.
1) Bulletin de la Chambre d'Agriculture de la Cochinchine 10 (1907), September number, p. 36; Report of Schimmel & Co. April 1908, 32. 2) Report of Schimmel & Co. April 1900, 12. 3) Ibidem April 1902, 21.
4) Ibidem April 1900, 13.
5) Ibidem April 1910, 29.
According to J. Dupont and L. Labaune1), isoamyl alcohol and isovaleric aldehyde are contained in Java citronella oil, but the investigators do not report the methods of identification employed.
Properties. The Java or Singapore citronella oil is characterized by a much finer odor and hence constitutes the more valuable commercial article. It is colorless to slightly yellow, has a specific gravity of 0,885 to 0,901 at 15°, and reveals a slight laevorotation, as a rule not exceeding 3°. In recent years slight dextrorotation («D up to + 1°47' has also been observed but in very exceptional cases only2)). The index of refraction nD20o fluctuates between 1,465 and 1,472. The oil forms a clear solution with 1 to 2 vols, and more of 80 p. c. alcohol. Rarely does opalescence set in upon dilution.
The amount of acetylizable constituents (socalled total geraniol) is much greater than in Ceylon citronella oil, being not less than 85 p. c. in good oils. In order to enable proper comparison, the acetylation must be conducted under like conditions as described under Ceylon citronella oil (p. 229). The separate determination of geraniol and citral can be carried out as with the Ceylon oil. Using the phthalic acid anhydride method, Schimmel & Co.3) found 26,6 to 38,2 p. c. of geraniol in several Java citronella oils. In an oil containing 83,8 p. c. of total geraniol and 26,6 p. c. geraniol, the phenylhydrazine method yielded, according to the length of the reaction period, 36,4 and 41,3 p. c. of citronellal whereas the oxime method yielded 46,6 and 43,5 p. c.4). The formylation method, applied to several other oils yielded 23 to 35 p. c. which results, however, may be regarded as too low.
1) Berichte von Roure-Bertrand Fils April 1912, 8.
2) Report of Schimmel & Co. April 1908, 32. - Jaarb. dep. landb. in Ned.-Indie, Batavia 1907, 67.
3) Report of Schimmel & Co. April 1900, 12; October 1912, 43.
4) Ibidem October 1912, 47.