RHEUM OFFICINALE, Rheum palmatum

RHEUM OFFICINALE, Rheum palmatum.—大黃 (Ta-huang), 1225. This is also called 黃良 (Huang-liang), “yellow efficacy,” and 將軍 (Chiang-chün), “Captain-general,” both referring to the esteem in which it is held as a drug. It has been known in China since the time of the Five Rulers (circa 3000 B. C.). The Emperor Shennung and Leikung, who is said to have lived in the reign of the Emperor Huangti, considered the drug to be poisonous; hence it is classed among the poisons in the Pêntsao. It is produced in the north-western provinces, but that coming from Kansu is considered the best. The plant grows six or seven feet high, and the stem is brittle and has a sour taste. The stalks were formerly eaten raw. The leaves are coarse, long, and thick, and the flowers vary in different varieties, being yellow, green, or red. The root in the fresh state is red, bowl-shaped, and nearly two feet long. It is pulpy, and is easily attacked by worms. It is usually cut into slices, placed on heated stones and partially dried. Afterwards it is strung together on twine and dried in the sun. Sometimes the drying is completed by artificial heat, and in this case the drug is not so apt to become wormy. A kind of rhubarb, called 土番大黃 (T‘u-fan-ta-huang), comes from Thibet or Turfan. Another called 土大黃 (T‘u-ta-huang), and which is found in the north-eastern provinces is Rheum rhaponticum; but in Japan is a Rumex. Good Chinese rhubarb is of a reddish-yellow color, variegated or mottled, and firm in texture, showing evidences of considerable deposits of raphides in its structure. The pieces should be dry and not too light. When chewed, the root should grate upon the teeth, have a bitter and sharp rather than smooth flavor, and color the saliva with a deep yellow tinge. Boracic acid should not color the external yellow surface a dark brown. The purgative properties of rhubarb are not made so much of by the Chinese as they are in the west. It is regarded more as a general eliminant and tonic to the digestive tract. Depurative properties are also ascribed to it in a marked degree. It is recommended in diseases of women, especially those attended by congestion of the pelvic organs, such as dysuria and dyspareunia. It is also used in malarial fevers and the fevers of children.