On the effect of frictional electricity I have had such very small experience that I cannot venture to speak with any confidence, and the accounts that I have heard from others whose experience is much larger have not led me to attribute much importance to this agent. If I am to judge at all, I should say it merely acts as a skin-stimulant, and is, in that capacity, inferior to many other simpler and more facile applications. Very different is the verdict of experience as regards the effects of the constant current; here the results which I have obtained have been so remarkable that even now I should distrust their accuracy, were it not that they are in accord with the general result which (among minor discrepancies) may be gathered, we may fairly say, from all the more important researches that have lately been carried out in Germany. The constant current, as I now estimate it, is a remedy for neuralgia unapproached in power by any other, save only blistering and hypodermic morphia, and even the latter is often surpassed by it in permanence of affect; while it is also applicable in not a few cases where blistering would be useless or worse. The English medical profession has not as yet adequately appreciated the necessity for great care in the choice of apparatus and the mode of application of electricity. It is all-important, however, and especially in the case of applying galvanism for the relief of pain. The first quality that must be absolutely required in a battery, that is to be used for this purpose, is that it shall deliver its current with as little as possible variation of tension, in fact that it shall be constant, and not merely continuous; a vast majority of all the various galvanic apparatus that have been used have been merely the latter, and have consequently been almost valueless for the relief of pain. Such are Pulvermacher's chains, the voltaic piles made with elements of metallic gauze, Cruickshank's battery, and many others that have been used. A sufficiently constant current may be obtained from either of the following apparatuses, (1) Daniell's battery, (2) Bunsen's, (3) Smee's. For hospital use, the Daniell battery (in Muirhead's modification, or with the form of cells introduced by Siemens-Halske) is perhaps the most desirable; but for private practice it is worth while to sacrifice something of the superior constancy which we gain in the Daniell battery for the sake of comparative portability. All purposes which we aim at in the electric treatment of neuralgia may be sufficiently obtained by the use either of the Bunsen battery (zinc-carbon, excited by dilute sulphuric acid), as modified by Stohrer, or by the Smee battery (zinc and platinized silver, excited by dilute sulphuric acid), as in the highly convenient apparatus devised by Mr. Foveaux, of Weiss & Son's. It must be remarked that, for the purpose of treating neuralgia, we shall never need to employ more than fifteen, or at the utmost twenty, cells