Abstract
In order to make the mechanism of santonin action clear the author has carried out the experiments. Result : (1) Santonin has little effect on Ascaris suillus kept in Bunge's solution. It makes never the survival time of ascaris shorter than that of the intact one. (2) Calomel, phenolphthalein and bitter salt has also little effect on ascaris. But, if given with santonin, they shorten slightly the survival time and inhibit its movement. (3) Santonin from Artemisia monogyna, when given with hydrogen sulfide, shows the paralytic action on ascaris, which is due to the : change of optical rotatory activity induced thereby.Even in this case the survival time is not shortened. (4) The solution, in which santonin and hydrogen sulfide are mixed together, exerts a remarkable more toxic action on ascaris than in the case of hydrogen sulfide alone. The analogous facts are obtainable by the combination of sodium santoninate, allantolactone and hydrogen sulfide. From the above-mentioned results it may be said that, though ascaris dwells usually in the human intestine and possesses some resistance to hydrogen sulfide, it would be paralysed or killed when deprived of his resistance under the influence of santonin.
