It follows from these experiments that we may, at pleasure, arrest electricity in the skin, and that without puncture or incision we may make the current traverse the skin, and concentrate its action upon subcutaneous organs. It was at one time objected that the muscular contraction was the result--not of irritation limited to the muscle or its motor nerves--but of reflex action; but Duchenne demolished this objection by a vivisection. Having removed the skin from the face of a living rabbit--to whom chloroform had been administered--he divided the facial nerve of one side only, in order that the muscles supplied by it might be cut off from all connection with the cord. He then applied electric excitation to each muscle of the face, alternately, on the two sides. The muscles contracted separately and equally on both sides. He then destroyed the brain of the same animal, in order to place the cord in a condition favourable to the production of reflex action, and again excited the muscles as before. The results were absolutely the same.[11] Muscular electrization may be produced either--as I have just shown you--by placing the conductors upon the muscle itself, a procedure termed _direct_ or _intra-muscular_ electrization, or by exciting only the motor nerve trunk, which is termed _indirect_, or _extra-muscular_ electrization, and which we shall consider presently. [Illustration: FIG. 13. Cylindrical Sponge-holder.] [SN: Different kinds of Rheophores.] For direct excitation of the larger muscles it is convenient to use well-moistened sponges, contained in cylinders of different sizes, or metallic disks, covered with wet leather and having conveniently shaped handles. A useful size of cylinder is one such as this (see Fig. 13), having a depth of about 1-1/2 by 1-1/8 inches, which allows the sponge to fairly fill it, while in such forms as this--6 inches by 1--when the sponge is inserted the lower three-fourths of the cylinder is empty, and the conduction of the current liable to become imperfect. Such a cylinder as this, without any insulating handle at all, is worse than useless, and is a still persisting relic of the barbarous time when the patient was invariably electrized by causing him to hold the conductors one in each hand, a proceeding extremely dangerous in certain pathological conditions, and in other cases not likely to be of benefit to him. The insulating handles should be well hollowed out, that they may be used, lying comfortably between the fingers, when holding two in the same hand. The disk rheophore (see Fig. 14), a metallic button covered with wash-leather, is extremely useful; it has the advantage over the sponge of allowing firm pressure to be made without the inconvenience of water being squeezed out, while by using its edge it may be made to answer in the majority of cases for a pointed conductor, which is fitted chiefly for application to very small muscles, such as the interossei and some of those of the face.