1901 - 2 .] Mr James Bussell on Magnetic Inductions. 313 
When the superposed force H 2 carries the B 2 component round 
a complete magnetic cycle, the component due to Hj kept at 
a constant value responds and likewise passes through a complete 
magnetic cycle or series of cycles. 
A connection appears to exist between the change which takes 
place in the B x component and the permeability impressed upon 
the iron by the magnetising force which is superposed. This is 
especially well marked when Hj is constant and the superposed 
force cyclic, the maximum and minimum values of B x corresponding 
with the maximum and minimum values of dB 2 /dH 2 respectively. 
The whole phenomena, however, are exceedingly complicated — 
permeability, retentivity, coercive force, and vibration effects all 
contributing to the final result under the various conditions of 
field superpositions. 
II. During the early stages of induction, the experiments de- 
scribed show that iron is more permeable to a reapplication of a 
magnetising force in the same direction (positive or negative) as 
that used in the immediately preceding process of demagnetising 
by decreasing reversals, than it is to a force (positive or negative) 
at right angles to that used in the immediately preceding de- 
magnetising process. The difference for the two qualities of iron 
used was found to be of the order of 30 per cent., but it vanishes 
as the magnetising force is increased. 
An explanation of this magnetic aeolotropy of demagnetised iron 
based upon the molecular theory of induction is given. 
[Issued separately October 7 , 1902 .) 
