300 



LOCALIZED ELECTRIZATION. 



two binding-screws A A' (fig. 82), and traverses the electro-magnet 

 D, and the inductive coil B ; the pieces E, v, a, constitute a Neef s 

 trembler. The instrument furnishes an extra current.^ 



Fig. 82. — Apparatus of Du Bois-Reymond. 



" A second reel B', wound with a fine wire, may either cover the 

 first completely or be removed to a distance from it. This is 

 the seat of the induction. 



"The inductive coil contains wires of soft iron, the number of which 

 may be varied so as to graduate the effects in another manner. 



" The apparatus is very simple, and very well contrived with 

 regard to experimentation, and for all that regards the graduation 

 of the induced currents."'^ 



(e). Morins apparatus. — " This instrument was one of the first 

 to fulfil the conditions of convenience required for the carrying 

 out of electro-therapeutics in private practice ; and among the 

 most useful of ]M. Morin's arrangements may be reckoned the close 

 combination of the battery and the induction coil. The com- 

 bination was the more difficult, as it was accomplished under the 

 condition of employing a Bunsen's battery, only slightly modified. 



" Fig. 83 gives a general view of the apparatus. The battery 

 and its accessories are placed in the division to the right. A is a 

 planchette, to which is fixed the induction apparatus properly so 

 called ; and at A' the same system is shown uncovered. 



Fig. 84 exhibits a section of the coil. D is a tube of tin, which 

 can be withdrawn at pleasure, together wdth various rods of iron 

 wire ; G is a movable copper cover, which acts as graduator ; then 



® Le Eoux, loc. cit., p. 53. The original influence of the coils, of which the outer 

 instruments of my own, presented in 1848 one was movable. Tiiis disposition has 

 to the Academy, liad a movable arrange- been imitated by M. Du Bois-Reymond ; 

 ment of the coils, the thick wire being I shall presently explain for what reason I 

 internal and fixed ; and were graduated myself abandoned it. 

 in the same manner by the reciprocal | ' lb., p. 54. 



