Fodor and Reifenberg published a paper purporting to show that nicotine is decomposed by an ezymie in tobacco juice or extract. To confirm the finding we made a study repeating their experiments. For the determination of nicotine we used several methods such as Kissling's, Toth's, Okuda's, and Chapin's and also Fodor-Reifenberg's. The analytical results obtained agree d in all the four methods except Fodor-Reifenberg's, which as a rule gives a lower value of nicotine. As the results of experiments, we failed to ascertain th e findings of Fodor and Reifenberg, and come to the conclusion that there is no enzyme spliting nicotine in tobacco juice and extract. The discrepancy should be ascrib e d to the incompleteness of their method of determining nicotine, and also to the fact that their experiments lacked proper cotrol examinations.