The electronic variation with strong polarising currents / by G.N. Stewart.

  • George Neil Stewart
Date:
[1889?]
Catalogue details

Licence: Public Domain Mark

Credit: The electronic variation with strong polarising currents / by G.N. Stewart. Source: Wellcome Collection.

    4/20
    The Elect rotonic Variation with Strong Polarising Currents. By George N. Stewart, D.Sc., Owens College, Manchester. (Read January 21, 1889.) Let AB (fig. 1) be a piece of nerve interposed in the galvano¬ meter circuit, and CD in the battery circuit. Then, as has long been Lnown, on closing the battery circuit, one obtains a current in the galvanometer circuit, the direction of which in the nerve is the same as that of the polarising current. If, now, stimulation be made, say at 1, this current undergoes a negative variation. Hermann, who investigated the subject, after Bernstein, was at first inclined to explain the negative variation by his law of “ polarisation increment.” He assumed that the excitation in passing along a polarised nerve undergoes changes in its intensity, increasing as it passes through regions under the influence of the anode, decreasing as it passes through parts dominated by the cathode. Fig. 1. How, if the current be ascending in the nerve (fig. 1), the electrotonic current in AB is also ascending. As B is nearer the cathode than A, the excitation will pass B in less intensity than A. Accordingly, during tetanus, B may be considered as less negative than A. In other words, B will be positive to A, and a current of