1863.] 651 



the muscle will contract tonically as long as the current passes ; and 

 if it be increased in intensity, cramp will eventually be induced. 



The positive pole may be placed upon almost any part of the body 

 to produce this effect ; only as it is removed farther from the muscle 

 to be acted on, the intensity of the current must be progressively 

 increased. 



A healthy muscle contracts with more vigour if the current be 

 direct that is to say, the positive pole towards the centre, the nega- 

 tive pole towards the periphery. 



If a muscle paralysed from recent injury to the brain be acted 

 upon in the same way, it will be found to contract more vigorously 

 than a healthy one under the same intensity of current. 



If an extensor muscle paralysed and wasted, the result of poison- 

 ing by lead, be treated in the same way, no contraction can be induced 

 even with the highest power of the apparatus ; the unparalysed 

 flexors will alone contract. 



If a muscle paralysed and wasted from loss of nutrition, as in those 

 local paralyses which are the sequelae of fever, the exanthemata, con- 

 vulsions, irritation during teething, &c., be acted on in the same way, 

 no contraction can be induced ; if the current is increased in intensity, 

 the healthy or antagonistic muscles contract. 



In these two latter instances after treatment by the continuous 

 galvanic current, when circulation has been re-established, and the 

 paralysed muscles are better nourished if the current be reversed, 

 the positive pole placed on the insertion of the muscle, and the 

 negative pole on the belly, and if the current is not too strong, faint 

 contraction takes place, gradually increasing until the muscle is 

 sufficiently restored to contract under the direct stimulus. 



A singular fact in connexion with these paralysed and wasted 

 muscles is, that they will contract at the will of the patient, for some 

 time, before they will do so to the stimulus of the current ; but the 

 paralysed muscles are not safe from a relapse until they contract 

 vigorously to the ordinary direct electrical stimulus. 



At a certain stage of improvement, when the paralysed muscle will 

 neither contract to the will nor to the electro-magnetic current, it will 

 do so to the combination of the two. 



