The chemical constituents of the rhizome of the AmericanPodophylZum pltatum have, however, been made the subject of several investigations, First, in 1832, Hodgson prepared the mixture of resins known and largely used in medicine as " podophyllin," by precipitating a concentrated alcoholic extract of the rhizome with water ; this is now manufactured on a large scale, and is the form in which ' podophyllum ' is usually administered as a drug. The first important contribution to the chemistry of

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... odophyllum was that made by Podwyssotski (Phamn. Journ., [iii], 12, 317, 1011); this chemist showed that the rhizome did not, as was previously supposed, contain the alkaloid berberine; he isolated from it three substances which he named podophyllotoxin, podophyllic acid, and podophylloquercetin respectively. To the first of these he attributed the characteristic purgative action of the drug, but the others he believed to be physiologically inert ; the first two he did not succeed in obtaining in a crystalline condition, the third was a crystalline, yellow colouring matter. H e further showed that when podophyllotoxin is acted on by a1 kaline solutions, it is decomposed, furnishing two new substance8, one crystallising in long needles with a silky lustre, which he named picropodophyllin, and the other a gelatinous substance having the characters of an acid, which he called picropodophyllic acid. Kursten (Arch. Phurm., 1891, 228, 220-248), who considerably VOL. LXXIIT. P 189 1).