90 EMPLOYMENT OF ELECTRICITY 



current, with the exception of two, one of which, 

 for the sake of contrast, was extracted without 

 the employment of the machine, and with the 

 other, the current accidentally failed to pass ; and 

 the whole of the operations, with the exception of 

 those two, one of which was very painful, were 

 perfectly satisfactory. There is a great advan- 

 tage in varnishing the portions of the forceps 

 which come in contact with the gums, and inside 

 of the mouth, since the whole of the action is thus 

 confined to the tooth. It must be borne in mind 

 also, that various portions of the tooth have 

 various conducting powers ; the lower and softer 

 portions conducting best. The nerve is the best 

 conductor of all ; consequently, the introduction 

 of a conducting wire into a deeply -excavated 

 tooth in which the nerve is exposed, or the con- 

 tact of a conducting wire with the amalgam 

 filling of a tooth, causes intense pain. 



It is the practice of some operators not to let 

 on the current of electricity until the moment of 

 extraction, whilst Mr. Spence Bate rather advo- 

 cates the plan of first ascertaining the strongest 

 amount of current which the patient can bear 

 through the tooth, and allowing it to pass 

 until it has begun to exert a benumbing influ- 

 ence, and he then, and not till then, extracts 

 the tooth. These variations of process must, 

 however, be still left to experience. Operators 

 will do well to tabulate their results, noticing age. 



