1838.] 



Electro-chemical Effects on Magnetising Iron, 



165 



Fm. 5. 



Section of interior of coil. 



Cupric Chloride, Cols. 5 and 6. — On caasing to magnetise, galvano- 

 meter deflections fell some degrees, but rose again on re- magnetising. 



During an investigation of the possible electro-chemical effect 

 between the polished end disks or polar terminals only, of straight 

 round steel magnets, there were indications, under certain conditions 

 and when the magnets were immersed as elements in some electro- 

 lytes, of a tendency on the part of the N. terminal plane of the 

 magnet to become from some cause electro-positive to the S. terminal 

 plane, when the magnets were placed parallel some distance apart in 

 an upright position. The lower end of each magnet exposed in the 

 solution was covered with black india-rubber tubing, so that the flat 

 polished disks at the terminals only were exposed to the action of the 

 electrolyte. This apparent tendency seemed somewhat singular, and 

 farther experimentation is required before arriving at definite con- 

 clusions ; it seemed desirable however to allude to this apparent 

 indication. 



I hope to make other observations in this direction, and in course 

 of these to utilise some valuable experimental suggestions which 

 Professor Stokes has kindly made. 



N 2 



