64 THE CHEMISTEY OF ESSENTIAL OILS
soil up to an elevation of 1800 ft. Occasionally it is cultivated, for
example in Eajputana and Chutia-Nagpur. In the Malay districts
vetiver only occurs cultivated or accidently growing wild;—the same
applies to the West Indies, Brazil, and E6union. The best sort of grass
is found in the neighbourhood of Tutikorin, which is still at the present
day the most important shipping port of vetiver root.
The vetiver oil prepared from the root does not appear to be distilled
in India itself or in the other countries of origin with the exception of
K6union.
Jowitt,^1 however, does not consider that the so-called Mana grass,
C. confertiflorus, is the true mother-plant of the cultivated citronella
grasses. He states that C. Nardus, the genuine citronella grass, also
grows wild in Ceylon. C. Nardus Rendle, which occurs in a wild state,
is identical with the so-called " old citronella grass " (Winter's grass,
Maha Pengiri) and forms a species distinct from Mana grass. It is pos-
sible that the third variety, known as Lenabatu grass, has resulted
from hybridisation of citronella and Mana grasses. In these circum-
stances Jowitt considers it advisable to designate the Maha Pengiri
variety as a separate species under the name of Cymbopogon Winter ianus.
In this case the name C. Nardus Eendle should be applied only to the
Lenabatu grass.
There are numerous intermediate plants between the regular culti-
vated varieties and the wild mother-plants, and the oils from these have
been investigated by Pickles,^2 whose results point to the fact that by
continued cultivation the oils become richer, in some cases in geraniol,
in other cases in citronellal, the former approaching Lenabatu oil and
the latter Maha Pengiri oil.
The principal oils belonging to this important family are the
following:—
CEYLON CITRONELLA OIL.
This oil is distilled in Ceylon, from the grasses described above, on a
very large scale. The oil, which is used in cheap perfumery, especially
in soap manufacture, is produced in more or less primitive stills, to the
extent of between 1,500,000 and 2,000,000 Ib. per annum. It is largely
distilled by natives, and is almost universally adulterated.
The grass is cultivated almost entirely in the south of Ceylon.
About 50,000 acres are devoted to it, and but little attention is necessary.
The growth is continuous, and three harvests can be obtained annually
in very favourable years, but usually two are found sufficient—one in
July or August and one in December, January, or February. The yield
of oil is about sixteen to twenty bottles (22 oz.) per acre for the summer
crop, and five to ten for the winter crop. After a lapse of fifteen years
the plants become exhausted, and new plants become necessary. There
are somewhere about 600 stills at work on the island, and the enormous
output of the oil indicates its importance as an article of commerce.
The distilleries are usually situated in small sheds and consist of a steam
boiler with a safety valve and water indicator, resting upon a solid
foundation ; two cylindrical stills 6 to 8 ft. high and 3 to 4 ft. broad, and
a spiral condenser in a tub of cold water. A still will produce from
20 to 30 Ib. of oil a day.
(^1) Annals Royal Botanic Gardens, Peradeniya, iv. 1908, 4, 185.
*Bull. Imp. Inst., 8 (1910), 144.