Some Limitations of the Kjeldahl Method. HARVEY C. BRILL and FRANCISCO AGCAOILI (Yhilippke J . Sci., 1917, ~Z A , [261][262][263][264][265] ,-The Kjeldahl method yields low results when applied t o the estimation of nitrogen in pyridine, piperidine, quinoline, isoquinoline, hydroxyquinoline, pyrrole, and sometimes in nicotine ; this is possibly due to the formation of sulphonic derivatives, which re& decomposition. I n the case of pyridine, the Gunning-Arnold method gives trustworthy results if

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... the heating is prolonged for a considerable period (four hours) after the solution has become clear. Low results are always obtained when sodium sulphate is used in place of potassium sulphate for raising the boiling point of the sulphate formed. A. J. w. titrated by Volhard's method. w. P. s.