Let us now suppose the machine to be working. We will take the B D current. Let it be of good medium strength. We regulate the strength by the quantity of fluid in the battery, so far as _volume_ is concerned, and by means of the plunger as respects _intensity_. The electrodes should be dampened with warm water. Let the _sponge-roll_, [a very thin expansion of sponge, quilted upon a muslin lining, and enveloping one of the tin electrodes], be made the positive pole, and be placed under the coccyx--lowest part of the spine. Then attach the _positive_ cord; that is, the cord connected with the _negative_ post, to another sponge-roll, to be held in the operator's right hand; or, what is better, attach it to a thin, flexible, metallic wristband, (brass is good, but metallic lace--such as is used in trimming _regalia_, is best), underlaid with wet muslin, and fastened around the right wrist. This brings the operator's hand into the circuit as the negative electrode or pole. Next, pass a moist, warm sponge all over the patient's back. Now, before the back becomes dry, press the points of two fingers firmly, yet not uncomfortably, upon the back of the neck at the base of the skull; thence move gradually downward, by frequent touches of the same firm but gentle character, keeping one finger on each side of the spinous processes, until the whole length of the spine has been, in this manner, passed over. If sharp pain or soreness be felt at any point, _note_ that point; there is inflamed irritation there. Then return up to the right or left shoulder, and pass, in like manner, by frequent touches with one or two fingers, over all parts of the back on that side of the spine, down to the hips. Then, in the same way, examine the shoulder and back on the other side of the spine, noting, as before, every point, if there be any, where soreness and pain appear. After this, pass over the entire neck, then over the front parts of the thorax and abdomen, down to the pelvic bones, everywhere watching for soreness and pain. Next, go to the head. Wet the hair through to the scalp, (because dry hair is a bad conductor,) and change to a _very soft_ B C current. Then go over all the head in the same manner as over the neck and trunk. Better _reverse_ the poles on the head, by transposing the cords in the posts, so as to make the manipulating hand the _positive_ pole. The head is, or ought to be, extremely sensitive. You need not do this, however, if the negative pole can be received on the head without discomfort, as it sometimes can be. Commence on the cerebrum, and then pass to the cerebellum.