VALUE OF GALVANIC CURRENTS IN MEDICINE. 227 



tion, even of a less degree of strength, is retained, and even somewhat 

 increased. 



Neumann has since observed the same phenomena, in the nerves and 

 muscles of frogs after the death of the animal, as in the paralysed muscles of 

 tlie face. Before the total loss of excitability, he has seen a period of diminu- 

 tion, often lasting for several hours, diiriug which the strongest induced 

 currents of the slide apparatus, with its cylinder pixshed in, were ineffectual 

 to excite contractions, while the completion and interruption of battery 

 currents from four or six of Siemens' elements produced a marked reaction, 

 both through the motor nerves, and in direct excitation of the muscles. 

 Neumann api:)lies to this phenomenon the above explanation ; namely, that 

 under the conditions present, a stronger momentary cui-rent produces a less 

 effect than the interruption and completion of a weaker one of longer duration ; 

 and he refers to the researches of von Bezold and Fick, according to whom, 

 next to the oscillations of tension, the time during which the current passes 

 at a constant height through nerve and muscle, forms an important factor of 

 the stimulation. 



In succession to these observations of Neumann, Bruckner has instituted 

 experiments on several patients suffering from fatty atrophic paralysis, and 

 has confirmed Neumann's view. On the paralysed muscles an induced 

 current had no action ; but a battery current of twenty elements produced a 

 contraction at closing. Briickner observed that this contraction at closing 

 did not take place immediately, as it does in sound or only slightly paralysed 

 muscles, but that a very small period of time intervened ; also that in slow 

 succession of comi^letion and interruption (from half to one second) the 

 contractions were greater than in quicker succession (four or five in a 

 second) ; that in changing the current by the commutator, the contractions 

 were yet more considerable than in slow interruptions and completions ; and, 

 lastly, that in approximating instantaneous interruptions of a continuous 

 current, the contraction wholly ceased. Briickner tested these facts on the 

 peroneal, crural, sciatic and tibial nerves, in this manner. The current 

 passed through a circuit completed by an electric key; and this circuit, by 

 means of a short gentle tap on the head of the key, was opened and instantly 

 closed again. During tliis momentary interruption, the contraction of the 

 muscle remained unaltered ; but in a longer interruption it always became 

 stronger. That an interruption actually took place, is rendered evident by 

 Briickner's test experiments. With how many elements he worked on the 

 individual muscles and nerves, and whether he went on to employ currents 

 of considerable strength, are not stated. He concludes by saying that, so far 

 as any conclusion can be drawn from his few experiments, a certain tardiness 

 of the nerves with resi^ect to the electrotonic state is not to be mistaken, 

 since they require a longer duration of current in order to be brought into 

 this state, and, when so brought, a longer interruption in order to lose it, and 

 in a momentary interruption they continue in it. 



For the last observations bearing upon this question we are indebted to A. 

 Eulenburg. He saw the case of a girl, twenty years old, who had suffered for 

 eight weeks from complete facial paralysis of the right side, of rheumatic or 

 traumatic origin. With normal cutaneous sensibility the affected side had 

 completely lost its excitability by intermitting currents, either intra- or extra- 

 muscular, either with slow or rapid interruptions, or with changing the direc- 

 tion of the current. Faradization, and the subcutaneous injection of strych- 

 nine, in the course of forty-one days, produced no alteration whatever. A 

 galvanic current from eighteen defective Daniell's elements was then 

 employed ; this, although so weak that it produced no trace of effect upon 

 the sound side, either motor or sensory, produced strong contractions on the 

 diseased side, especially when both poles were placed ujdou the face. After 

 seven sittings, the paralysis was decidedly improved, but the difference in the 

 action of the two kinds of current was unaltered. After nineteen' sittings 

 (from February 27 to March 17) the deformity was removed, and the power 

 of voluntary movement was restored. Notwithstanding this, the reaction to 



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