INDUCTORIUM. 



189 



The E.M.F. of the currents in the secondary bears a direct relationship to the 

 E.M.F. of the currents in the primary. Thus, if there are 200 turns in the P and 

 6,000 in the S, the E.M.F. of the induction currents will be approximately 30 times 

 that of the inducing currents, independently of the influence exerted by the iron core. 



Connect up the secondary circuit of the Inductorium. 



(Fig. 26 S.) It is well to do this in all cases first. 



Fasten a key to the table close to the left - hand end of the 

 machine as it now rests on the table, and connect the binding screws 

 of the S coil with those of the key, by means of two wires, " so 

 that when the key is closed the S circuit is thereby also closed. 

 This is the short circuiting key in the secondary circuit. 



Now attach the long circuit wires, by means of which the 

 connection is to be established, with the seat of stimulation, i.e., 

 attach the hand electrodes by their metal tags to the binding screws 

 which already hold the S wires. 



B 



FIG. 26. Inductorium of du Bois Reymond. 



Connect up the P coil for single induction currents. (Fig. 26. ) 

 Place the Leclanche cell upon the table near the right hand end of 

 the coil, and attach a key to the table close to. 



Keep the key open. In making the connections always begin at 

 the battery, and follow the direction the current will take. 



