234 LOCALIZED ELECTRIZATION. 



obtain a more energetic contraction, it is necessary to use a cur- 

 rent that is more intense. 



The muscular shocks produced by the intermissions diminish as 

 the latter become more rapid ; and at a certain rate of speed the 

 contraction appears to be continuous, as if it were produced phy- 

 siologically by the nervous current, that is, by the -will. For this 

 it is necessary, however, that the rapidity should be extreme ; 

 since otherwise the resulting movements will resemble a kind of 

 tremor. 



B. — Upon muscular sensibilitij. — I have just shown that the force 

 of the muscular contraction is not augmented by increasing the 

 I'apidity of the intermissions. The case is different as regards 

 the muscular sensation produced ; for this is always augmented by 

 increasing the rapidity. When a high degree of speed is attained 

 the sensation becomes very painful, almost tetanic, and is attended 

 by cramps. 



C. — JJpon muscular tonicity. — I have found by experience that 

 currents of rapid intermission augment the tonic power of muscles, 

 not only when this power is diminished, as we see it in certain 

 conditions of disease, but also when the muscles are in their normal 

 state. This special effect of rapid intermissions, when it is long 

 continued, may even produce shortening ; and facts on which this 

 statement rests will appear in subsequent pages. It will then be 

 seen how I was led to observe this phenomenon, and also that, in 

 order to produce it, the currents must be of extreme rapidity. 



D. — Ujyou muscular nutrition. — The nutrition of muscles some- 

 times becomes very much increased under the influence of currents 

 of rapid intermission. The cases of muscular atrophy or of atro- 

 phic paralysis, in which I have compared the effects of currents of 

 slow and of rapid intermission, place this statement beyond doubt. 

 However, it is necessary to use the latter with circumspection ; 

 because, in certain morbid conditions, they may destroy the re- 

 maining innervation of the muscles. 



E. — Upon electro-cutaneous sensiUlitij. — It is enough to experi- 

 ment upon one's self in order to be convinced that the electro- 

 cutaneous excitation increases in direct proportion to the rapidity 

 of the current rather than in proportion to its intensity. 



To complete the account of the influence of the rapid inter- 

 missions of an electric current upon the sensibility, I should add 

 that, generally, every organ that receives the nerves of animal life 

 is excited by any current, the more painfully the more rapid are 

 its intermissions. 



Finally, the muscles of organic life— of the intestines, for example 

 —contract more powerfully if the intermissions are more rapid. 



