LAURUS CAMPHORA, or "kusunoki," as it is called in Japan, grows mainly in
those provinces in the islands Shikobu and Kinshin, which have the southern
sea coast. It also grows abundantly in the province of Kishu.
The amount of camphor varies according to the age of the tree. That of a
hundred years old is tolerably rich in camphor. In order to extract the
camphor, such a tree is selected; the trunk and large stems are cut into
small pieces, and subjected to distillation with steam.
An iron boiler of 3 feet in diameter is placed over a small furnace, the
boiler being provided with an iron flange at the top. Over this flange a
wooden tub is placed, which is somewhat narrowed at the top, being 1 foot 6
inches in the upper, and 2 feet 10 inches in the lower diameter, and 4 feet
in height. The tub has a false bottom for the passage of steam from the
boiler beneath. The upper part of the tub is connected with a condensing
apparatus by means of a wooden or bamboo pipe. The condenser is a flat
rectangular wooden vessel, which is surrounded with another one containing
cold water. Over the first is placed still another trough of the same
dimensions, into which water is supplied to cool the vessel at the top.
After the first trough has been filled with water, the latter flows into
the next by means of a small pipe attached to it. In order to expose a
large surface to the vapors, the condensing trough is fitted internally
with a number of vertical partitions, which are open at alternate ends, so
that the vapors may travel along the partitions in the trough from one end
to the other. The boiler is filled with water, and 120 kilogrammes of
chopped pieces of wood are introduced into the tub, which is then closed
with a cover, cemented with clay, so as to make it air-tight. Firing is
then begun; the steam passes into the tub, and thus carries the vapors of
camphor and oil into the condenser, in which the camphor solidifies, and
is mixed with the oil and condensed water. After twenty-four hours the
charge is taken out from the tub, and new pieces of the wood are
introduced, and distillation is conducted as before. The water in the
boiler must be supplied from time to time. The exhausted wood is dried and
used as fuel. The camphor and oil accumulated in the trough are taken out
in five or ten days, and they are separated from each other by filtration.
The yield of the camphor and oil varies greatly in different seasons. Thus
much more solid camphor is obtained in winter than in summer, while the
reverse is the case with the oil. In summer, from 120 kilogrammes of the
wood 2.4 kilogrammes, or 2 per cent. of the solid camphor are obtained in
one day, while in winter, from the same amount of the wood, 3 kilogrammes,
or 2.5 per cent., of camphor are obtainable at the same time.
The amount of the oil obtained in ten days, _i.e._, from 10 charges or
1,200 kilogrammes of the wood, in summer is about 18 liters, while in
winter it amounts only to 5-7 liters. The price of the solid camphor is
at present about 1s. 1d. per kilo.
The oil contains a considerable amount of camphor in solution, which is
separated by a simple distillation and cooling. By this means about 20 per
cent. of the camphor can be obtained from the oil. The author subjected the
original oil to fractioned distillation, and examined different fractions
separately. That part of the oil which distilled between 180°-185° O. was
analyzed after repeated distillations. The following is the result:
Found. Calculated as
C_{10}H_{16}O.
C = 78.87 78.95
H = 10.73 10.52
O = 10.40 (by difference) 10.52
The composition thus nearly agrees with that of the ordinary camphor.
The fraction between 178°-180° C., after three distillations, gave the
following analytical result:
C = 86.95
H = 12.28
-----
99.23
It appears from this result that the body is a hydrocarbon. The vapor
density was then determined by V. Meyer's apparatus, and was found to be
5.7 (air=1). The molecular weight of the compound is therefore 5.7 × 14.42
× 2 = 164.4, which gives
H = (164.4 × 12.28)/100 = 20.18
or C_{12}H_{20}
C = (164.4 × 86.95)/100 = 11.81
Hence it is a hydrocarbon of the terpene series, having the general formula
C^{n}H^(2n-4). From the above experiments it seems to be probable that
the camphor oil is a complicated mixture, consisting of hydrocarbons of
terpene series, oxy-hydrocarbons isomeric with camphor, and other oxidized
hydrocarbons.
_Application of the Camphor Oil_.
The distinguishing property of the camphor oil, that it dissolves many
resins, and mixes with drying oils, finds its application for the
preparation of varnish. The author has succeeded in preparing various
varnishes with the camphor oil, mixed with different resins and oils.
Lampblack was also prepared by the author, by subjecting the camphor oil to
incomplete combustion. In this way from 100 c.c. of the oil, about 13
grammes of soot of a very good quality were obtained. Soot or lampblack is
a very important material in Japan for making inks, paints, etc. If the
manufacture of lampblack from the cheap camphor oil is conducted on a large
scale, it would no doubt be profitable. The following is the report on the
amount of the annual production of camphor in the province of Tosa up to
1880:
Amount of Camphor produced. Total Cost.
1877.......... 504,000 kins.... 65,520 yen.
1878.......... 519,000 " .... 72,660 "
1879.......... 292,890 " .... 74,481 "
1880.......... 192,837 " .... 58,302 "
(1 yen = 2_s_. 9_d_.)
(1 kin = 1-1/3lb.)
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