46 LOCALIZED ELECTRIZATION. 



the surface of the same muscle. It is necessary that the extremities 

 of the exciters should always be at least two centimetres distant 

 from each other. The force of the discharge is regulated by the 

 number of revolutions of the plate. If only a feeble contraction 

 be desired, the exciter K is brought near to the skin after one or 

 two turns only. To obtain a stronger contraction, a greater or less 

 number of additional turns must precede the discharge. It may 

 happen, however, from error or inadvertence, that the jar is too 

 powerfully charged ; and that its discharge may produce either a 

 very strong contraction, or an action that penetrates to one of the 

 neighbouring muscles, or a very painful sensation, that is followed 

 by general excitement contra-indicated in the particular case. It 

 is to avoid such mischances, troublesome and sometimes dangerous, 

 that I use Lane's electrometer. Of its two uprights, H and F, 

 the former is movable, and can be made to approach or recede 

 from the latter by the screw M. A scale of millimetres, placed at 

 the base of H, indicates the distance between the balls J' and E'. 

 Before discharging the jar upon a muscle, I regulate the force by 

 approximating or separating these balls, according to the degree 

 of excitability of the muscle, the region in which it is situated, 

 and the therapeutic end that is desired. If I should be deceived 

 about the number of turns of the plate, the jar cannot be over- 

 charged, because the accumulated vitreous and resinous electricities 

 will remiite and neutralize each other between the two knobs E' 

 and J', as soon as they acquire sufiScient tension to overcome the 

 resistance of the intervening air ; a resistance which is well known 

 to be in direct proportion to the distance between the knobs. 



Is it desirable to have recourse to the advantages of the above 

 procedure of muscular electrization, in the application of tension 

 electricity ? Is it not evident that it concentrates its action upon 

 the muscles that require treatment, without exposing healthy 

 organs, and especially the nervous centres, to the dangers of an 

 inopportune excitation ? Tiie procedure admits of directing very 

 strong discharges upon the muscles, when their pathological con- 

 dition needs such, either from atrophy, or from diminution or loss 

 of their irritability or sensibility. 



When, on the contrary, the exciters are placed far apart, or one 

 of them is held, according to common practice, in one hand of the 

 patient, while the other is brought near to the diseased organ or 

 part on which the therapeutic action of electricity is to be directed, 

 we see the local effect complicated by phenomena of shock more 

 or less extended or general ; so that we cannot, without danger, 

 exceed very weak doses. 



The phenomena of general shoclc are always the result of ex- 



