32 



LOCALIZED ELECTRIZATION. 



We cannot, therefore, in the present state of knowledge, find a 

 satisfactory physical theory of the differential physiological pro- 

 perties of the currents of the first and of the second helix ; and we 

 must be content, for the time, with a simple recognition of incon- 

 testable facts. 



§ II. — Differential therapeutic ]^rojperties of the induced currents. 



Induced electricity is the only therapeutic agent which, limited 

 to the skin, is capable of producing acute cutaneous sensation 

 which ceases suddenly with the operation, which can be graduated 

 from simple titillation to the most acute pain, either through all 

 intermediate degrees, or by passing suddenly from one extreme to 



cannot be entirely due to the differences is composed of two straight electro-mag- 

 in their tension. ; nets B and D, furnished with induction 

 " I have demonstrated by the apparatus bobbins at their polar extremities, that 

 represented in the figure (fig. 1); which when tlie two armatures E F and G H 



Fig. 1. 



are let down over the poles of the 

 magnets, the induced currents excited by 

 the closing and ojiening of the inductive 

 current across the bobbins A and C, 

 although more intense in their action 

 U4)on the galvanometer than when the 

 armature E F is raised, give much more 

 powerful shocks in the latter case; and 

 yet the two currents, measured by the 

 rheostat, have the same tension. It is 

 impossible to ascribe this difference of 

 action to the difference in the rapidity 

 of the demagnetization of the magnetic 

 centres in the two cases; because the 

 same effects are produced by interrupting 

 the two inductive and induced currents 

 simultaneously by means of a double 

 toothed wheel. Moreover, this effect is 

 not the only one of its kind that could 



be cited; and I have shown tJiat, imder 

 certniu circumstances, the inverse current, 

 which never gives api:)reciable physio- 



I logical effects, yields some that are more 

 energetic than those of the direct current. 



i Furthermore, we know that the negative 

 pole of the induced current re-acts most 

 powerfully upon the animal economy; 



, although the experiments of M. Eiess 

 and myself have shown that the current 

 of the positive pole possesses the gi-eater 

 tension. We must therefore conclude, as 

 I have said, that the reciprocal relations 

 between the nervous system and tlie 

 action of electricity are not sufficiently 



! understood, in the present state of science, 



! to furnish us with a priori explanations 



[ of all the phenomena that have been 



; observed." 



