VALUP] OF GALVANIC CURRENTS IN MEDICINE. 223 



strychnia rendered the diplegic contractions more percej)tib]e, where they 

 were at first wanting. 



It shonld not be supposed that Eemak has not actually witnessed these 

 phenomena. In hysterical people — and of such lie treated great numbers — 

 far more wonderful things occur. It may be remarked, however, that the 

 observations are at present wholly without corroboration from trustworthy 

 jiersons. 



The more dissatisfied we leave this region of obscure observations, insuffi- 

 ciently founded diagnosis, and hypothetical explanations of doiibtful curative 

 actions, the more contented shall we be to retui'n to the basis of facts, which, 

 gained by means of sober inquiry, are already recognized as valuable scientific 

 property. 



These observations refer to the changes produced by the electric current 

 in the irritability of paralysed nerves and muscles with regard both to 

 volition and to the electric stimulus. 



Between 1840-50, it was established by Duchenne, that induced currents 

 usually quickly improved the excitability of enfeebled or completely paralysed 

 muscles, when their electric contractility is retained or only slightly enfeebled, 

 At the same time he concluded that complete loss of electro-muscular 

 cont" n.ctility was a most unfavourable symptom with regard to paralysis in 

 general ; indicating long duration of the condition, and great resistance to 

 the action of remedies. In traumatic paralysis of mixed nerves, in which 

 total loss of electro-muscular contractility was present, Duchenne declared 

 the application of indiiced currents to be useless during the first six to ten 

 'months, since the nerve injury was not yet repaired. Afterwards benefit 

 might be expected from faradization. 



Duchenne subsequently observed the remarkable phenomenon that the 

 increase of excitability of motor nerves or muscles, produced by the induced 

 current, was often only displayed in resjionse to the stimulus of the will ; so 

 that therefore the motility returned while the absence of excitability by 

 induced currents continued. In lead-jxalsy, traumatic paralysis, and paralysis 

 of the facial nerve, Duchenne found that muscles might contract faultlessly 

 in response to the will, and perform designed movements, while they were 

 perfectly insensitive to the excitation of induced currents. 



These facts have since been frequently observed. We may now consider 

 it established : — 1. That paralyses, affecting the same nerves or muscles, and 

 proceeding from similar lesions, may display either a normal degree, a diminu- 

 tion, or a complete loss of faradic contractility. 



2. That the increase of excitability by the will, produced by the aiiplication 

 of faradic currents, occurs quickly or immediately in the two first cases; 

 slowly, or not at all, in the third. 



8. That the excitability of the paralysed nerves and muscles by the will, 

 under the application of indiiced ciirrents, completely returns, in many cases ; 

 while the excitability by the induced current is still absent, and returns only 

 subsequently to the former. 



Recent years have much enriched oiu" knowledge upon this subject, by 

 many interesting and practically important facts, gained by Eemak's applica- 

 tion of battery currents in paralysis. 



Eemak, in the course of his experiments, came first to the conclusion that 

 constant "labile" currents increased the irritability of motor and sensitive 

 nerves both against the same currents and the induced, while at the same 

 time the mechanical power of action was increased ; biit that induced currents 

 which certainly somewhat increased the irritability, diminished the power of 

 muscular action. 



These experiments were performed by Eemak preferentially upon diseased 

 but also upon healthy muscles and nerves. Unfortunately his accounts of the 

 results are inexact and confusing, by the strange style of description. I there- 

 fore only extract what is for the present question important ; that, according 

 to Eemak, " the irritability of muscles and nerves for induced currents, and 

 for the entrance and exit of constant currents, remains, as a rule, uniform, so 



