I shall describe under this head the _modus operandi_ of administering a routine galvanic or faradic bath. As it will become necessary to describe special modes of administration when speaking of the electro-balneological treatment of special diseases, the describing them now would only lead to tautologies that I am desirous of avoiding. Taking our cue from the indications to be met in each case, it becomes necessary, according to circumstances, to use either the galvanic current, the faradic, or both successively. As modifications of the application of the currents we have to consider 1) their intensity; 2) their direction, and 3) the duration of the application. The intensity of the galvanic current corresponds directly to the number of cells from which it is derived. It were vain however to attempt to express this in figures, because the electro-motive force of different batteries varies to so great an extent, that a number of cells of some batteries of low intensity yield a current so feeble as to be barely appreciable in the bath, while the same number of cells of a battery of high intensity, furnish a current that few persons can bear without pain. In thus comparing the Hill cell with the Stöhrer cell, I have found the ratio to be about as 1 to 2½, i.e., as intense a current can be derived from twenty-four Stöhrer as from sixty Hill cells—and this is rather below than above the mark. Were all batteries alike in this respect, however, still no particular number of cells could be given as furnishing a current of suitable average intensity for the galvanic bath, because of the excessively great variations in the degree of electro-sensibility of different persons. This is so marked that I have seen persons in the bath tub who could bear no more than six Hill cells, diffused as was the current from these through the water and over the entire body; while on the other hand I have met with male patients on whom a current from thirty-two Stöhrer cells made not the slightest impression, and where I was compelled to supplement the current by that from a ten-cell quantity battery (zinc carbon elements 6 in. long by 4½ wide) in order to make them realize the presence of a current. These gentlemen had no cutaneous anæsthesia. In view of the facts just stated, I have found it impracticable, when giving directions for the administration of a galvanic bath, to indicate any certain number of cells to be used. I am in the habit of ordering the administration of a “mild,” a “medium” or a “strong” current, as may be required in the respective cases; and in every instance it is the electro-sensibility of the patient that determines the number of cells requisite to obtain the desired result as represented by one of these terms. The same applies also to the faradic current.