A chemical investigation has been undertaken of Rauwolfia caffra, a South African tree, the bark of which is reputed to possess therapeutic value. The investigation has thus far yielded three crystalline bases, one of which, identified as a new alkaloid, has been named rauwolfine and provisionally assigned the formula C20H26O3N2.2.5H2O. Some of the properties of the alkaloid, including its pharmacological action, and the preparation and properties of its halogen salts are described. © 1932, American Chemical Society. All rights reserved.