Dr. A. Schuster's Experiments on Electrical Vibrations. 311 



paper "On Unilateral Conductivity." 

 shown by the following diagram : — 



& 



The arrangement is 



& 



UJe 



G is a galvanometer, the resistance of which was 2477 mer- 

 cury units; I is the induction-coil within which the rotating 

 magnet is placed ; C is a commutator ; E a Darnell's cell. 



It is seen by the diagram that only a small part of the perma- 

 nent current passed through the galvanometer, as the resistance 

 of the wire a b was very small compared with the resistance of the 

 galvanometer. The experiments were conducted in the following 

 way : — 



1. The rotating magnet was first left fixed in a certain posi- 

 tion, and the first deflection produced by E was measured. It 

 was found that this deflection was the same in whatever position 

 the magnet was fixed ; and we may therefore conclude that the 

 reaction on the current of the magnetization produced by the 

 current was too small to be observed. The magnet was set in 

 rotation now after contact had been broken at c; and when the 

 needle in G had come to rest again, which was done in a very 

 short time (the galvanometer having a strong logarithmic decre- 

 ment), the first deflection produced by E was measured. It 

 was found that the first deflection was always larger when the 

 magnet rotated. The following is a series of observations which 

 I take at random out of my laboratory book. 





First deflection, in 

 scale-divisions. 





322 

 333 

 321 

 327 

 311 

 321 

 307 

 320 

 305 









ouiet 



„ rotating 



auiet 











325-25 

 313-20 







Difference 



1205 





2. By altering the resistance of the wire a b, I could alter the 

 strength of the permanent current without sensibly affecting the 



