The principle of the method of investigation was previously described. Here some further technical data are given and possible errors are discussed. Veratridine exercises a depolarizing action on the myelinated nerve fibers of the frog. The degree of depolarizing activity depends on the concentration of the drug. The resting potential of veratrinized nerve fibers depends to a large extent on external Na concentration. Further, the effect of veratridine on K depolarization was studied: it was increased. The effect of Ca free and Ca rich solutions, as well as that of cocaine-Ringer solution, of dinitrophenol and KCN was studied. It is stated that the veratridine action seems mainly due to an increase of Na and K permeability.