8 LOCALIZED ELECTRIZATION. 



Electrization by sparks produces a sensation analogous to that 

 of whipping, and appears principally adapted for cases in which 

 it is necessary slightly to stimulate the skin ; although it would 

 be insufficient if very active stimulation were desired. In fact, 

 to obtain such active stimulation, it would be necessary to have 

 recourse to static electricity of high tension, such as would be 

 furnished by the Leyden jar, and which would also produce such 

 muscular contractions and general shock as to complicate the 

 action upon the skin, and to contra-indicate the employment 

 of the agent. Electrization by sparks is, therefore, useless in 

 cases of profound and obstinate anaesthesia, or where it is wished 

 to produce an instantaneous revulsion, such, as would be effected 

 by the actual cautery. 



Electrization by sparks, even wben they are yielded by a 

 powerful machine, and by spherical exciters, is only able to produce 

 contraction of some superficial or very excitable muscles, such as 

 the platysma, the upper half of the sterno-mastoid, the margin 

 of the trapezius, and some muscles of the face. In order that 

 static electricity may affect the muscles generally, especially 

 when they are covered by an abundance of cellular tissue, it would 

 be necessary to employ a high tension by means of a Leyden jar. 

 But the resulting shock, which would possibly extend to the 

 nervous centres, would render such an operation dangerous or 

 impracticable. 



The knowledge of the local organic changes produced by the 

 discharge of a Leyden jar enables us better to appreciate the thera- 

 peutic action. It has been already shewn that an organ so elec- 

 trified only undergoes excitation after having suffered, for some 

 time, from all the effects of torpor. It is easy to conceive that if 

 any organ were exposed to discharges too frequent or too powerful, 

 or if its vitality were already depressed, the stage of electric torpor 

 might be indefinitely prolonged. 



However favourable may be the conditions under which it is 

 attempted to practise muscular electrization by the Leyden jar, it 

 will always be imprudent to expose tlie patient to many discharges. 

 Hence it would be impossible to electrify all the muscles in cases of 

 paralysis of one or more of the limbs. 



Moreover, the operation is always painful ; since the cutaneous 

 excitation inseparable from the use of static electricity increases in 

 proportion to the increase of tension. 



It appears, then, on the whole, that the excitation of muscles by 

 static electricity ought generally to be excluded from practice, and 

 the more so since it may be replaced by another electric agent, 

 which will be described in the third section (induced electricity) ; 



