1891.] on the Mclecular Process in Magnetic Induction. 399 



Another tiling on which the theory throws light is the phenomenon 

 of time-lag in magnetigation. When a piece of iron is put into a 

 steady magnetic field, it does not take instantly all the magnetism 



Fig. 14. 



Hysteresis in the changes of magnetism produced by applying and remoA'ing load. 



that it will take if time be allowed. There is a gradual creeping up 

 of the magnetism, which is most noticeable when the field is weak 

 and whenlhe iron is thick. If you will watch the manner in which 

 a group of these little magnets breaks up when a magnetic force is 

 applied to it, you will see that the process is one that takes time. The 

 first molecule to yield is some outlying one which is comparatively 

 unattached — as we may take the surface molecules in the piece of iron 



