Electro-physiology and electro-therapeutics : showing the best methods for the medical uses of electricity / By Alfred C. Garratt.

The dentists galvanic caulerizer, as made by Mr. Thomas Hall, of this city, (see page 155,) may be thus described : The insulating handle is made of ivory or ebony, and contains some six inches of the terminal ends of, (or can be attached to,) the two battery conductors. These tips are copper wires plated with silver or gold, which are separately embedded in the ivory, and thus insulated safely, but so arranged that one of them can be opened or closed by a delicate touch of the thumb-spring. Now, on the extremities of these tips is a very fine piece of platinum wire, — say a hundredth part of an inch in thickness only, and three quarters of an inch in length, — which is bent into a loop, so as to connect the two poles. The sides of this loop are brought parallel and as nearly close to each other as possible without touching, so that the current must pass around, and in this shape it is introduced into the pulp cavity of the tooth to be operated upon, ready to be plunged upon, or into, the nerve as soon as heated ; then, by a slight pressure on one side of the handle, the interrupted pole is temporarily united in good metallic contact, so that the platinum-pointed loop- tip instantly becomes brilliantly heated, and is then carefully pressed into the tooth-pulp. The flexibility of the platinum loop-tip, which is the cauterizer, enables the operator to bend it in any direction, previously to use, but always so that the current must pass around the very extreme acute angle of the loop, or all is a failure. In this way Dr. Harding says he has been very successful in quickly destroying the pulps of decayed and condemned teeth, and has proceeded, sometimes after only a few minutes, to the filling with gold, or other stoppings, as the metallic paste. The fact is, this instrument is nothing more nor less than Middeldorpff's electro-port-cauterizer, with adjustable tips for dentists' or surgeons' use. (See cuts of apparatus, page 155.) Of the operation, this celebrated den- tist says, — " The affected tooth being carefully examined, its cavity is to be well dried out and cleansed. A soft napkin is introduced, to protect the mouth ; the platinum point of the instrument is then passed over or into the cavity of the tooth and when all