For surgical operations, as a substitute for the knife or ecraseur, a platinum wire is placed between the poles of a powerful battery, the wire being adjusted in a handle, which in a few minutes becomes red hot, and is especially serviceable for operations in deep cavities where it would be impossible to use the knife, the application of such a galvanic cautery being unattended by pain or hemorrhage. The Galvano-Cautery consists of a platinum wire loop heated by passing a current of electricity through it, the heat being maintained as long as the current passes. Such an appliance will cut through the tissue to which it is applied without causing much hemorrhage.

Electric portable mouth lamps are also employed for illuminating the mouth and examining the teeth, and carious cavities in them.

Strong currents of electricity should not be applied to the head, nor its use be persevered in for more than fifteen minutes at a time.

Electro-magnetism has been employed for relieving pain during the extraction of teeth, one pole of an ordinary battery being attached to the forceps and the other to a handle which is grasped by the patient. The susceptibility to the current is first ascertained by the patient holding both the forceps and the handle in his hands, and a feeble shock applied, which is gradually increased until the sensation is felt at or just beyond the elbows, when the current is somewhat reduced in power. After the gum has been lanced, the connection is made as before described, by the patient holding the handle and the operator the forceps in contact with the tooth to be removed, the handles of the instrument being isolated, when the operation is at once completed. Great diversity of opinion, however, exists as to the efficiency of this method, which has its advocates and opponents.