164 PHYSIOLOGICAL PHYSICS. [Chap. xv. 



(4) As a means of detecting malingerers electricity 

 must, of course, be used with caution. If a strong 

 induced current fail to produce contraction, paralysis 

 is evident, for the contraction set up by electricity is 

 beyond voluntary control. Though contraction be 

 produced, however, it does not follow that nothing is 

 amiss. Faradisation of the dry skin with the wire 

 brush, if strong enough, is very painful, and may 

 without danger be employed. 



(5) Within, at most, two or three hours after 

 death induced currents of electricity fail to provoke 

 a response from the muscles. Failure to elicit re- 

 sponse is, therefore, a sure sign of death. Moistened 

 electrodes should be employed in the test, and the 

 skin also should be well moistened with warm salt 

 water. 



Electricity is employed in therapeutics 

 as (1) stimulant and counter-irritant, (2) sedative and 

 antispasmodic, (3) for electrolysis, (4) as cautery. 



(1) Obviously the commonest use of the stimulat- 

 ing properties of electricity is in paralysis. Where the 

 paralysis is central, and disuse has caused wasting of 

 the nerves and muscles, electricity is employed to 

 restore their tone and improve their nutrition. The 

 induced current is used, and of a strength just 

 sufficient to produce contraction, and the faradisation 

 ought to be local. It is obvious that the only benefit 

 to be expected in such cases is the restoration of the 

 normal state of the muscles and nerves as to their 

 irritability ; it is equally obvious that electricity 

 cannot be expected to restore voluntary motion, whose 

 abeyance is due to the central lesion, and whose 

 restoration is dependent upon the nature of the lesion. 



In peripheral paralysis, where the lesion affects 

 the centres in the cord or the nerves and produces 

 rapid degeneration of nerves and muscles, electricity 

 frequently yields marvellous results. Faradisation is 



