The parts of‘ Spruce's material that reached the Department of Toxicology, Karolinska Institutet, Stockholm, in April 1968 consisted of five pieces weighing in all 26.7 g. : 11.5 g. were worked up for analysis by gas chromatography-mass spectrometry and other methods as described earlier. The yield of alkaloids was found to be 0.4 per cent. A newly collected sample was found to contain 0.5 per cent and harmine, harmaline and tetrahydroharmine with two additional minor components. By contrast, the alkaloid content of the Spruce material consisted exclusively of harmine. It is open to question whether the stems sent home by Spruce in 1853 from the beginning contained only harmine or perhaps more likely that harmaline and tetrahydroharmine have with time been transformed into the chemically more stable aromatic beta-carboline, harmine.