History.—Gold-thread is found growing in the northern parts of the United States, following the Appalachian range as far south as northern Alabama, and in Canada, Greenland, Iceland, and Siberia. It grows in dark swamps and sphagnous woods, flowering from early in the spring to July. “Northern cedar and spruce and balsam swamps always abound with it. Another favorite habitat of the plant is the cold swamps, such as are found in mountain plateaus. It often grows freely in beds of sphagnum and other mosses, especially in wooded swamps. Although coptis is a swamp plant, it is not a mud plant, but generally selects the dry knolls surrounded by wet soil” (C. G. Lloyd, Drugs and Med. of N. A., Vol. I, p. 195). At one time it was so popular as a domestic remedy that more of it was sold in Boston than almost any other indigenous drug (Bigelow). It is now but little employed. Autumn is the season for collecting coptis, when it should be dried with care. Its properties are imparted to water, but more perfectly to alcohol, and the solutions are precipitated by nitrate of silver and acetate of lead.
Action, Medical Uses, and Dosage.—Gold-thread is a pure and powerful bitter tonic, somewhat like quassia, gentian, and calumba, without any astringency. It may be beneficially used in all cases where a bitter tonic is required, and is decidedly efficient as a wash or gargle, when in decoction, in various ulcerations of the mouth. In the nursing sore mouth of mothers we have repeatedly and promptly cured with the decoction when infusion of hydrastis had no effect. This would seem to indicate that its virtues are not wholly dependent upon berberine as is generally supposed.
Action, Medical Uses, and Dosage is transcribed to the end of its fourth sentence; it continues on p. 604 with a compound and doses.