IN a former paper' it was shown that the two hyoseyamines differ to a marked extent in their pharmacological action, the laevorotary natural base possessing a very powerful action on the terminations of the nerves in the salivary glands, heart, and iris, while the dextrorotary artificial base is almost devoid of effect on these organs, but exercises a stronger stimulating action on the central nervous system of the frog. The action of atropine (racemic hyoscyatmiine) is the resultant of the action of its two components, lavo-and dextro-hyoseyamine, and it thus affects the nerve terminations about half as strongly as levo-hyoscyamine, while possessing a more distinct stimulant action on the central nervous system. The difference in the effect of-lhevo-hyoscyamine and the dextrorotary alkaloid was first inferred from a comparison of the actioif of atropine and hyoseyamine, and was then confirmed by the study of dextro-hyoscyamine.A review of the literature concerning the action of optical isomers on vertebrates was given in that paper but two further examples of differentiation between the isomers have since been added. Mayor2 states that levo-nicotine, the natural alkaloid, is twice as toxic to guineapigs as the artificial dextro-nicotine. The lavorotary base irnduces pain when injected hypodermically, while the dextrorotary has nio such effect, and there appears to be some difference in the nature of the convulsions, those following dextro-nicotine having a prevailing tremulous character, while those induced by levo-nicotine are more violent and set in more abruptly. Neuberg and Mayer3 found that d-mannose' undergoes more rapid oxidation in the tissues of the rabbit than 1-mannose, and that the injection of inactive mannose is followed by the appearance of 1-and inactive mannose in the urine. Glycogen is formled from inactive

THE history of physiological investigation in regard to the movements of the uterus is a comparatively short one and up to 1891 has been dealt with fully by Helme'. Few papers on the subject have appeared since until the last two years, during which Kurdinowsk i2 and Franz3 have published the results of numerous experiments; Dale4 has recently taken it up in the course of his work on ergot.

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(From the Pharmnacological Laboratory of the Univer.sity of Michigan, U.S.A.)THE similarity in the action of belladonna and hvoseyamus preparations has led to a number of researches on the relative power of their active constituents, and Ladenburg's discovery that atropine and hyoscyan-ine are optical isomers has added further interest to the subject. The atropine used by most investigators was crystalline, and probably a fairly pure product, but the so-called " hyoseyamine " appears in the great majority of instances to have been merely a purified extract of hyoseyamus, which certainly' contained hyoscine, and probably atropine and other bodies as well as the alkaloid hyoseyamine. It is scarcely necessary to state that such comparative studies are valueless unless the alkaloids are absolutely pure, and it is accordingly unnecessary to discuss the results of these earlier workers'. Hellmann2 used the hyoscyamine of Reichardct and Hohn, which was less contaminated than the ordinary hyoseyamine of that time, but appears to have been far from pure, and Eckhard', Buchheim4, Harnack5, Hartmann' and Gnauck7 all used the crystalline hyoseyamine prepared by Merck from hyoseyamus. This was undoubtedly an advance in the study of the alkaloids, but the well-known difficulty in isolating hyoscyamine and in preserving it unchanged suggests a doubt as to the purity of the preparations8, and this doubt is confirmed by the numerous contradictory results obtained by these observers.

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