According to Y. Asahina1), the Chinese drug To-ko consists of the entire plant (herb, rhizome and rootlets) of Asarum Blumei, Duch. It contains 1,4 p. c. of a volatile oil of a yellow color and an odor similar to that of sassafras; d15o1,0788; [a]D + 5°3'; A. V. and S. V. 0. As to its constituents, the presence of eugenol, safrol and of a terpene-like body was proved. According to Asahina the drug known in commerce by the names of Sai-sin or Si-sin and which is said to be obtained from Asarum Sieboldi, is likewise obtained from A. Blumei, and is therefore identical with To-ko.