Berberine exists in the root of the common barberry (Berberis vulgaris), in the calumba root of India (Menispermum palmaturri), and in the calumba wood of Ceylon (M. fene~ stratum). It is prepared as follows: -
(1) A soft watery extract of the root or wood is digested in rectified spirit, with trituration, as long as anything is taken up; the resulting tincture, after repose, is filtered, and the alcohol is gradually distilled off until the residue has the consistence of a thin syrup. The crystals which form as the liquid cools are drained in a funnel, washed with a few drops of ice-cold water, pressed dry in bibulous paper, and then purified by solution and crystallization, first in rectified spirit, and then in distilled water.
(2) The root or wood, coarsely powdered, is digested in rectified spirit, and treated as in (1).