The investigation of the crystalline alkaloid previously isolated from the bark of Strychnos Henningsii is continued. Analyses of the material isolated by the authors, as well as of material prepared by the firm of E. Merck of Darmstadt, Germany, suggest the formula C₂₁H₂₄N₂O₄(OCH₃), which differs from the one previously put forward. The compound contains one methoxyl group but no methylimido group and is probably phenolic, though attempts to methylate it with diazomethane to ascertain the number of hydroxyl groups proved abortive. The crude alkaloid is accompanied by very small quantities of a second crystalline alkaloid, which can be removed by continuous percolation with ether and purified by high vacuum sublimation (0.03 mm, 190-200°C). Analyses suggest the new alkaloid has the formula C₂₂H₂₆N₂O₅, differing from the first crystalline alkaloid (C₂₁H₂₄N₂O₄) by an increment of CH₂, and they may be monomethoxy and dimethoxy derivatives of the same mother substance. The new alkaloid has a melting point of 214.5-215°C (corr.), with a molecular weight found to be 446 and 412 (calculated 426). A mixed melting-point with β-colubrine showed a considerable lowering, excluding identity, but it gives a similar violet colour reaction to the two colubrines with Froehde's reagent, gradually turning to blue. There is also evidence of a third crystalline alkaloid, and the investigation is being continued.