Specification of Alfred Vincent Newton : instruments for extracting teeth.

  • Alfred Vincent Newton
Date:
1858
Catalogue details

Licence: Public Domain Mark

Credit: Specification of Alfred Vincent Newton : instruments for extracting teeth. Source: Wellcome Collection.

    5/8 (page 3)
    Newtons New Combination of Instruments for Extracting Teeth. ^~- .i - ■ ■ . .— .■- ■■ ■ ■— ■ ■ ■ . .......... —... — . ■ - -. -—.. — —-—- - i — ■ — combining with a common dental forceps a magneto-electric machine in such manner that a wire from one pole of the machine shall form a metallic con¬ nection with the part of the forceps that grasps the tooth, while the other pole of the machine is brought into connection with the patient’s hand by a second 5 wire. The handles of the forceps, which are held by the operator, are better to be insulated by being covered with gutta percha or similar non-conducting substance. In the accompanying Drawing, A represents in perspective view an ordinary magneto-electric machine, with a battery B attached; D represents the 10 ordinary dental forceps. A wire C passes from the negative pole of the electro-magnetic machine to the point a of the forceps, where a close metallic connection is made. On the inner side of the forceps, at the point d, a small metallic cup is placed, and a small copper stem projects from the opposite side e of the forceps: As the parts / and g of the forceps close upon the tooth 15 where it is surrounded by the gum, the induced current from the magneto¬ electric machine passes through the wire C, and across from d to e, and thus applies itself around the whole tooth in the vicinity of the nerves, and so affects the nerves as to render them temporarily insensible. The patient operated upon must hold in one of his hands the extremity of the other wire H 20 (which is attached to the positive pole of the machine), so as to complete the circuit through his body. I represents the hands of the operator grasping the forceps, and K the hand of the patient grasping the wire passing to the positive pole of the machine. The magneto-electric machine has a sliding rod, by which the induced current may be varied in intensity, as is well 25 understood. The intensity of the current to be passed through the patient’s tooth should be graduated by observing in advance how much he can con¬ veniently bear when he grasps the extremity of the wires H and C in each hand. A little practice will enable the dentist to determine this readily. The magneto-electric machine A is of the ordinary form employed for medical 30 purposes, and consists of a battery of one cell, a primary coil, an inducing coil, a small electro-magnet for breaking and closing the circuit through the wires C and II and the patients body. Any other form of magneto-electric machine may be employed. I have described above particularly the machine frequently called an electro- 35 magnetic machine, and which is used for medical purposes. There are several other forms of machine sometimes classified as electro-magnetic or magneto¬ electric which are known to be equivalent in their action on the nervous system to the one above described, such, for example, as the double helices or coils composed of two coils of wire, one surrounding the other, one being a