By the middle of the nineteenth century, the euphorigenic agent of Cannabis sativa was determined to be an alkali-insoluble, nitrogen-free principle.1 Between 1840 and 1895 most chemical investigations of cannabis and its extracts were attempts to find tests that would identify a hemp extract. The "Beam Test" became a favorite. Hemp extract produces a purple color when treated with 5- percent methanolic potassium hydroxide, and the test was assumed to indicate the active principle of the extract. Later, however, R. Adams and his coworkers were to show that the test does not indicate a substance with marihuana activity.
Around 1895, T. B. Wood, W. T. N. Spivey, and T. H. Easterfield isolated cannabinol from cannabis extracts.2 Cannabinol was considered to be the active principle until about 1932. Wood and the others also tried to determine the structure of the cannabinol molecule. However, the Cambridge chemists were unable to complete their investigative program because of a series of tragic accidents. Wood, after taking some cannabinol at the time he was preparing zinc ethyl, lost consciousness; the zinc ethyl ignited, and but for a difficult rescue he would surely have perished. Easterfield lost his life in a violent laboratory explosion while attempting to hydrogenate cannabinol, and Spivey suffered a similar fate while studying nitro-cannabinolactone.3 Cannabinol was not isolated again until R. S. Cahn succeeded in 1932.4 Cahn determined the structure of the molecule in all but the orientation of the substituent groups. He also cast doubt on the euphorigenic activity of cannabinol.
Not long after Cahn's work, University of Illinois chemists led by R. Adams isolated cannabinol by a method different from Cahn's; as a result of their procedure they isolated a new con-