50 Scientific Proceedings, Royal Dublin Society. 



nickel wire in a magnetic field of 200 c.g.s. units is increased by about 60 per 

 cent, for a direct field and about 80 per cent, for an alternating field of 

 frequency 150 per second. 



For assistance in reading the microscope I am indebted to Mr. A. V. 

 Henry, a third-year Experimental Science Teacher -in-Training in this 

 College. 



