Saxifraga.—Garreau and Machelast have isolated from S. crassifolia L.and other species of this genus a crystallizable bitter substance, bergenin. It is obtained by boiling the stems of the plants with absolute alcohol, after the tannin has been removed by ether. It crystallizes in alcohol, has a bitter taste, melts at 140° C. (284° F.), and burns up completely at 300° C. (572° F.). It is soluble in 167 parts of 90 per cent. alcohol and in 830 parts of water, but is more soluble in these liquids at a boiling temperature; it is faintly acid to litmus, and is not changed by treatment with dilute sulphuric or hydrochloric acid, but by diluted nitric acid is concerted into oxalic acid. Concentrated sulphuric acid decomposes it. Its formula is given as C6H3O3.H2O. Bergenin is asserted to be intermediate in its action between salicylic acid and quinine. (A. Pharm., 1881, 293.) The rhizome of Saxifraga ligulata Wall., which is used in India, in dysentery, has been found by David Hooper to contain about 16 per cent. of gallic and tannic acids, but no other active principles. (P. J,, Aug., 1888.)
The Dispensatory of the United States of America, 1918, was edited by Joseph P. Remington, Horatio C. Wood and others.