Experiments on pure solutions and on commercial samples have shown in general, that small amounts of sodium may be determined satisfactorily by the direct magnesium uranyl acetate method as long as the amount present does not fall below 0.2 mg. Lesser weights may be determined in special cases by the use of unusually small volumes of solution and reagent. The use of a more concentrated reagent leads to high results with the usual procedure and is not helpful in the quantitative precipitation of minute quantities of sodium.