“…Known acids were dissolved in oil with subsequent determination of neutralization number in order to compare the results obtained employing four different procedures-namely, A. S. T. M. using methyl alcohol as a solvent, A. S. T. M. using ethyl alcohol as a solvent, alkali blue, and electrometric. The latter method was carried out with the two previously described reference electrodes (5,6). The concentration The estimation of acidity in oils employing the alkali blue procedure has been found to give more satisfactory results than the A. S. T. M. procedure.…”