232 LOCALIZED ELECTRIZATION. 



CHAPTEE IV. 



ELECTRO-MEDICAL INSTRUMENTS, WITH REGARD TO THEIR AP- 

 PLICATION IN PHYSIOLOGY, IN PATHOLOGY, AND IN THERA- 

 PEUTICS. 



The choice of a good apparatus is of great importance in the 

 practice of localized electrization. To what purpose, indeed, 

 should we be skilful in the art, if the apparatus at our command 

 were unable to respond to the requirements of physiological, patho- 

 logical, and therapeutical research ? 



I therefore purpose, in this chapter, first, to examine the pro- 

 perties that should be possessed by electro-medical instruments ; 

 secondly, to describe the instruments that I have myself contrived, 

 and that appear to me to correspond with the progress of medical 

 electricity ; thirdly, to examine whether the instruments in com- 

 mon use possess the properties that are required. 



Part the First. 



the properties which instruments should possess. 



§ I. Ally faradic ajjparatus intended for medical iwactice, hut not 

 ])os§essing inimary and secondary coils, or in ivliich these coils 

 are not constructed after certain proportions of thichness and 

 length of wire, cannot ftdfil all the requirements of therapeutics. 



The foregoing proposition is but a deduction framed from the 

 electro-physiological experiments, and the facts detailed in § I., 

 p. 22 et seq., and which it would be superfluous to reiDroduce, or 

 even to recapitulate. The proposition cannot be disputed unless 

 the facts on which it rests can be disputed ; and these have been 

 submitted to the test of prolonged and public experiment, have 

 been sanctioned by many academic commissions, and have been 

 checked and witnessed by a large number of observers, both French 

 and of other countries. They therefore form part of science, in 

 spite of some ill-wishers, and of conduct that can only be explained 

 by ignorance, or bad faith, or malevolence. 



I have defined the conditions under which I have worked, in 

 order to obtain the electro-physiological results that I have de- 

 scribed. I have stated what, approximatively, should be the 

 diameter and the length of wire of the two coils for double induc- 

 tion, in order to endow them with the maximum of their difieren- 



