308 LOCALIZED ELECTRIZATION. 



from eacli of the two coils exert, as in the electro-dynamic instru- 

 ments, physiological actions which distinguish them apart, and 

 which severally fulfil special therapeutical indications. 



It follows from the facts, the experiments, and the considera- 

 tions, which I have already stated (Chap. I.) : — 



1. That the current of the second coil excites the retina more 

 acutely than that of the first coil, when it is applied by moist 

 rlieophores to the face, or to the eyeball (see A, p. 23). 



2. That the current of the second coil excites the cutaneous 

 sensibility more acutely than the current of the first coil (see 

 B, p. 24). 



3. That the current of the first coil excites, more acutely than 

 that of the second coil, the seusibility of certain organs situated 

 more or less deeply beneath the skin (see C, p. 24), 



4. That, in faradization of the nervous extremities by reflex 

 action, the current of the second coil produces more energetic 

 muscular contractions than the current of the first coil (see 

 D, p. 26). 



5. That when the moist rheophores are applied to the cutaneous 

 surface, the current of the second coil penetrates more deeply 

 into the tissues than that of the first coil (see E, p. 26). 



6. That the different physiological actions of the currents of the 

 first and the second coil cannot be applied indifferently in thera- 

 peutics (see A, p. 33), 



As a corollary to the foregoing propositions, we may conclude 

 that amj magneto- eledric apparatus intended for medical practice, 

 which does not jjossess first and second coils, constructed with certain 

 relative proportions of length and diameter of wire, tvill not fulfil all 

 the requirements of therapeutics. 



The foregoing considerations have not failed to exert a great 

 influence on the manufacture of magneto-electric instruments. 

 Indeed, either from understanding the importance of the matter, 

 or in order to supply the demands of physicians, the makers of 

 the magneto-electric instruments most generally found in medical 

 practice (MM. Breton freres, and Gaiffe) have applied double 

 induction to them. It is, doubtless, from forgetfulness that M. Le 

 Roux has failed to mention this important feature of Gaiffe's 

 instrument, on which, in other respects, he has bestowed a merited 

 eulogium. The omission is more to be regretted, since this skilful 

 manufacturer has endeavoured to find those relative proportions of 

 diameter and length of wire, with reference to the power of the 

 magnet, wliich will give to the coils the maximum of their different 

 physiological action. M. Gaiffe manufactures a small, a medium, 

 and a large magneto-electric instrument, and it is to the last two 



