In this short paper I wish merely to give a summary of the chief results of experiments made by me in February and March last in the Physiological Institute of Berlin. Du Bois Eeymond has recently made an elaborate investigation of the galvanic polarisation of muscle. Many years ago he made similar observations on nerve. The question which occurred to me was, How does tetanus affect the amount of polarisation in nervel? Apparently there has been no previous work at this subject. It is not necessary to describe here the arrangements used, nor the manner of making the observations, as a detailed aecount, with discussion of the facts brought out, will appear in the Journal of Physiology. When a current is passed through a living nerve, the polarisation produced may be either negative or positive. When it is negative, the polarisation current is, of course, in the opposite direction to the polarising current. Positive polarisation gives a current in the same direction as the polarising stream. It depends upon the “density” of the polarising current, and upon the time of flow, whether the deflection due to the polarisation is purely negative, purely positive, or of double sign. When it is of double sign, there is first a negative kick, which is followed by a more persistent positive deflection. As a matter of fact, there is every ground for believing, that in general the two polarisations exist side by side in the polarised nerve.