ACTION OP INTERRUPTED AND CONTINUOUS CURRENTS. 175 



to diminish the excitability of a nerve, and at the same time to 

 paralyse the limb under its control, by maintaining for a given 

 time the passage through the nerve of a continuous current of a 

 certain intensity ; that, by an intermittent direct or inverse cur- 

 rent,^ directed upon the nerve thus modified in its excitability by 

 the continuous current, one could act upon the contractility, or 

 upon the sensibility ; and that it was possible to re-establish 

 the excitability of the same nerves, by causing them to be tra- 

 versed by currents in the contrary directions (alternative voltaic 

 currents.) 



From the principal facts established by a series of experiments 

 upon animals, Matteuci thought himself able to draw electro- 

 therapeutic deductions. Of these, I will only cite the more 

 important. In speaking of the application of the various galvanic 

 currents to the treatment of paralysis, this skilful physicist says : — 

 " We must admit that, in some cases of paralysis, the nerves of 

 the limbs are altered in a manner analogous to the alteration 

 which is produced by the continuous passage of an electric 

 current. We have seen that, in order to restore to a nerve 

 the excitability which has been lost by the passage of a current, 

 it is necessary to expose it to the action of a current travelliyig in 

 an ojpposite direction. In the same way, to remove a paralysis, 

 we should cause the passage of a current in an opposite direction 

 to that which would have produced it. We hence suppose that 

 the paralysis that is to be subjected to electrical treatment is 

 either of sensation or of motion only. Thus, for paralysis of 

 motion, it is the inverse current that should be applied ; and for 

 paralysis of sensation, the direct current. In a case of complete 

 paralysis, there would no longer be any reason for deciding upon 

 the application of either one or the other.^ 



§ II. — Physiological action of continuous currents, direct or inverse, 

 applied to the nerves of man, upon sensibility, or muscular con- 

 tractility. 



I. — My first experimental researches. 

 I proceed now to the experimental researches that I undertook, 

 in the hope of being able to determine the value of the foregoing 

 therapeutical deductions. 



* A direct (centrifugal, or descending) \ nearer to the extremities. For the in- 

 current is produced by placing the rheo- \ verse (centripetal, or ascending) current, 

 phores over the course of a nerve, at a \ the position of the poles is reversed. Such 

 distance of two or three centimetres apart ; | has been the method employed by experi- 

 the positive pole being nearer to the menters. 

 nervous centres, and the negative pole | ^ Matteuci, he. cit., p. 266. 



