268 LOCALIZED ELECTRIZATION. 



If it is wished that the intermissions should be made slowly, the 

 knob L (fig. 61) must be turned till the line traced upon it is 

 directed transversely, since in drawing to itself the stem of the 

 rheotome until the bar E of the trembler is in contact with 

 the knob I, it completes the circuit formed by the battery and the 

 wire of the primary coil, which is broken by pushing back 

 the stem of the rheotome L. In this way an intermission is 

 obtained, and we may thus obtain a series more or less quickly. 

 If rapid intermissions of the trembler are desired, the button I 

 must be turned from right to left until the bar E, pushed forward 

 by a platinized eccentric fixed to the button, is sufficiently near to 

 the temporary magnet J, which is in contact with the soft iron in 

 the centre of the coil. The approximation is sufficient when the 

 noise of the trembler can be heard. It is necessary to regulate the 

 movements of the trembler carefully ; for if they are too rapid, 

 in consequence of too near an approach of the bar E to the magnet 

 J, the separations will be less complete, and the contact of the 

 portions of the trembler will be less perfect. It follows that 

 the power of induction will be diminished. We may also produce 

 small intermissions with the pedal rheotome Y (fig. 62), which 

 has been described (p. 259), and which is applied to the large 

 instruments. For this purpose, its conducting cords must be 

 attached to the knobs 3 and 4 (fig. 60), and then, after having 

 turned the button L from left to right, until the bar E is in contact 

 with the magnet J (in this position the battery current is inter- 

 rupted), the intermissions are to be made with the foot in the 

 manner already described. (By pressing on the knob 6, fig. 62, 

 the battery current is completed.) 



The electrode knobs, 1 and 2, receive the currents of each coil. 

 To them are fixed the conducting cords to which the rheophores 

 are attached. We can bring to these knobs the current either 

 of the primary or of the secondary coil, by pushing to the left or 

 to the right, as far as it will go, the stem of the commutator of 

 the coils C. The figures engraved upon the small plate of copper 

 traversed by this stem, point out the side towards which the stem 

 should be pushed in order to bring one or other of the currents to 

 the knobs 1 and 2. Lastly, the graduation is effected by the tube 

 D, as in the other instruments. In the intervals between the 

 applications, the battery current is interrupted by pushing back 

 the stem of the rheotome L, until the bar E is in contact with 

 the soft iron J. 



The small apparatus just described is that to which I give the 

 preference in the great majority of cases. I have recourse to the 

 large instruments only for the purposes of diagnosis, or for electro- 



