340 Dr. A. Schuster's Experiments on Electrical Vibrations* 



The laws which govern temporary and residual magnetism, 

 except so far as they have been hitherto given, I leave for the 

 future, when I shall have time for further experiment on the 

 subject to develop some points which are not yet quite clear. 



Troy, New York, U.S.A., 



April 1874. 



Errata in Vol. 46. 



Page 144, equation ( 2), fi rst term of second member, for (VRR'+s') 

 read (VRRW). 



— 144, second line of note, for vol. iv. p. 669 read vol. iii. p. 11. 



— 148, line 24 from top, for 14*51 read 14'15. 



Q2 Q2 



— 156, line 7 from bottom, for — read-^ . 



4 57 8n- 



XL VI I. Experiments on Electrical Vibrations. 

 By Ahthur Schuster, Ph.D.* 



I. Introductory. 



IN a previous paperf I described a curious effect of elec- 

 trical vibrations on the galvanometer-needle. The effect 

 could only be explained by assuming a different conductivity in 

 opposite directions. This unilateral conductivity, as it was called, 

 is never a stable phenomenon, but generally disappears very soon 

 by suitable manipulations. The condition of the circuit in which 

 no unilateral conductivity appeared was called the normal con- 

 dition of the circuit. The experiments which are described in 

 this paper were all made when the wire was in its normal con- 

 dition, and when, therefore, a magnet rotating in a coil of wires 

 connected with the galvanometer produced no effect on the gal- 

 vanometer-needle. 



It occurred to me to send a permanent current through the 

 galvanometer, in addition to the electrical vibrations induced by 

 the rotating magnet. From previously known facts it would 

 be expected that the electrical vibrations would counterbalance 

 each other independently of any permanent current going through 

 the galvanometer, and therefore that the permanent current 

 would produce the same deflection whether the magnet is rota- 

 ting or not. This, however, is not the case, but the rotation of 

 the magnet always increases the deflection of the permanent 

 current. 



II. Description of Experiments. 

 The instruments used were the same as those described in my 



* Communicated by the Author, 

 jf Phil. Mag. vol. xlviii. p. 251. 



