Fig. 506.—Cell Selector and Battery Arrangement.
Milliampèremeter.—The fact that a proper resistance has been forced in circuit is not alone sufficient to permit of the proper use of current for electrolysis. A measuring device should be included, as has been referred to and called the Milliampèremeter or Milliammeter. It is shown in [Fig. 507].
Fig. 507.—Milliampèremeter.
The method of connecting this instrument in series with the current from the rheostat has been shown in [Fig. 509].
The Electric Current.—Where the operating room of the physician is provided with street current it will be found more economical and cleaner to use that current for this purpose.
Usually the direct current is furnished of a voltage varying from 100 to 125 volts. To utilize such a current a wall plate is employed and connected to the circuit, as shown in [Fig. 508]. The resistance of an electric lamp is added to guard against injuring the patient if by any accident or negligence the circuit has been improperly closed.
