The amplification of the objects in the engravings is about 80 diameters.

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JAPANESE CAMPHOR—­ITS PREPARATION, EXPERIMENTS, AND ANALYSIS OF THE CAMPHOR OIL.

[Footnote:  From the Journal of the Society of Chemical Industry.]

By H. OISHI. (Communicated by Kakamatsa.)

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.