IN DENTAL OPERATIONS. 89 



which I have described, no electricity can pass 

 until the circuit is completely adjusted through 

 the patient; and a very small amount of insulation 

 will thus prevent the current from dividing and 

 passing, partly through the patient, and partly 

 through the operator when the circuit is closed. 

 For this reason, if the forceps or other instruments 

 be well covered with shellac varnish, except in the 

 portions which come into immediate contact with 

 the tooth, preserving always a clean portion for 

 perfect metallic communication with the wire of 

 the machine on the inside of the handle, this is all 

 the insulation that is really necessary; and I 

 venture to affirm that if the operator understands 

 the subject, he will need no other protection than 

 this. 



With regard to the amqunt of power required 

 for the most satisfactory results, operators vary 

 in their evidence according to their views of the 

 effect which they desire to produce. Those who 

 act upon the principle that the electric current 

 should produce an absence of all pain or sensation, 

 employ exceedingly small degrees of power, vary- 

 ing from 1^ to 2 degrees of the scale of my in- 

 strument ; whilst others, who look to the effect of 

 the benumbing influence of the current in masking 

 or disguising the character of the sensation felt, 

 employ stronger powers. 



I have known a case in which eighteen teeth 

 were extracted under the influence of a strong 



