LAUEACE^E
Some interesting information has been published recently by the
United States Consul at Swatow l on recent developments in the cassia-
producing industry.
He states that in 1910 Huang Hsi-ch'uan, a member of the
Chinese provincial assembly, instituted a series of experiments in
cassia-culture at Kaying, in the course of which it was found that the
soil and climate there were very suitable for the growth of this plant.
Huang Hsi-ch'uan had previously carefully studied the corresponding:
conditions at Wuchow, on the West river, where there are large cassia
forests, and accordingly he started a model plantation, not only, it is
said, with a view of making money from the undertaking, but especially
in order to promote industrial enterprise and to counteract the tide of
emigration among the people of the region. Two species of cassia are
grown in the new plantations, one large and the other small. The
former flowers when ten years old, but it is only cut down at the age
of twenty years for the purpose of harvesting the bark. Between the
ages of ten and twenty years only the seed, of which the value is small.,
is harvested. The smaller variety yields leaves for the manufacture of
oil at three to four years of age, and its bark is only harvested at the
age of six or seven years. As soon as the trees (and this applies to-
both varieties) are cut down, new shoots immediately spring up around
the stumps, so that such a plantation, once started, lasts practically in-
definitely. The wood is used for fuel, the wood-ashes and the small
twigs are employed for medicinal purposes, the bark yields the " cassia "
of commerce, and from the leaves oil is distilled.
Cassia oil is imported, principally from Hong-Kong, in leaden ves-
sels holding about 16£ Ib. It is always sold as of a definite content of
cinnamic aldehyde, the lowest commercial quality being 70 to 75 per
cent., and followed by 75 to 80 per cent., 80 to 85 per cent., and 85 to
90 per cent. The lower grades are usually adulterated, the usual
adulterant being common rosin, and if a 'really pure oil is required,
one containing 85 to 90 per cent, of cinnamic aldehyde should be in-
sisted upon.
A pure cassia oil should have the following characters:—
Specific gravity 1-055 to 1-072.
Refractive index 1-6000 „ 1-6060:
Optical rotation - 1° ,, + 6°.
Acid value 6 to 16 (rarely to 20),
Cinnamic aldehyde ..... rarely below 85 per cent.
The pure oil is completely soluble in 2 volumes of 80 per cent, alco-
hol, and usually in 3 to 4 volumes of 70 per cent, alcohol. The solu-
bility is impaired by most adulterants, such as colophony, heavy
petroleum oil or gurjun oil.
Colophony is indicated by a high acid value, and may be detected
and approximately determined by the lead acetate test. If to a solution
of 1 c.c. of the oil in 3 c.c. of 70 per cent, alcohol, there be added, drop
by drop, half a c.c. of a saturated solution of lead acetate in 70 per cent,
alcohol, no precipitate should be produced in the absence of colophony.
A precipitate indicates this adulterant. For an approximately quanti-
tative determination 5 grms. of the oil are dissolved in 20 c.c. of 70 per
cent, alcohol, and sufficient lead acetate solution as above added for com-
plete precipitation, 10 c.c. being the average quantity. Tl^e precipitate
1
Daily Consular and Trade Reports, 3 July, 1911.
VOL. I. 9