From the Cashew nut tree a milky _juice_ is obtained, by tapping or incision, which stains, of a deep black colour, whatever it touches. The fine black varnish so much used in China and Japan is the resinous juice of a tree called _fsi-chu_, which is conjectured to be the cashew nut tree. TRIGYNIA. 134. _The TRUE or OFFICINAL RHUBARB_ (Rheum palmatum) _is a medicinal root which grows wild in various parts of Asia._ _The leaves which issue from this root are large, and deeply cut into lobes; and the whole plant has a general resemblance to what in our country are called docks. The stem is erect and six or seven feet high. The leaves stand on footstalks, that are somewhat grooved above, and rounded at the edge. Those which proceed from the stalk supply at the joints a kind of membraneous sheaths. The flowers terminate the branches in clusters._ The importance and the properties of this _root_ in medicine are universally known. Rhubarb is usually imported from Turkey, but it is occasionally also brought from Russia, China, and the East Indies. Dr. Woodville states that the _Turkey rhubarb_ is brought over in oblong pieces, flattish on one side, and rounded on the other; and that it is compact, hard, heavy, and internally of a dull colour, variegated with yellow and white. The _Chinese rhubarb_ is in roundish pieces, each with a large hole through the centre. It is softer than the former, and exhibits, when broken, many streaks of bright red colour. In some of the mountains of Tartary, rhubarb plants are found in great abundance. The roots, when first dug out of the ground, are thick, fleshy, externally of yellowish brown colour, and internally of bright yellow streaked with red veins. When they have attained sufficient size, they are dug up and cleansed; and the small fibres and the rind being cut off, they are divided into pieces of proper size. Each piece is then perforated in the middle, and they are strung on cords in such manner as not to touch each other, and are suspended to dry, either upon adjacent trees, or in the tents.