70 The Principles of Magnetism. [February, 
These molecules are really independent bodies, and must 
exert inductive influence upon each other without regard to 
the fac5t that they are combined into the same general mass. 
A magnet, in fa<ft, is a mass of minute magnets, and in no 
respect differs in character from the earth as a mass of 
larger magnets. These molecular magnets seekto force each 
other into astatic relations ; but the local adtion in a regular 
mass of magnets of equal energy must be even less effica- 
cious than in the irregularly magnetic earth. The a(5tion of 
induction must become general instead of local with the re- 
sult that the molecules of the axial and surface regions must 
set themselves reversely parallel to each other. And the 
small testing magnet must become, virtually, a molecule of 
the large magnet, and assume, at every position, the same 
direction possessed by the molecules at that position. For 
such a small magnet could no more set itself up as an inde- 
pendent body than could a molecule of the larger mass or a 
magnetic needle as applied to the earth. 
The dip of the small magnet, then, indicates a like dip 
of the surface molecules. At the point where the small 
magnet stands perpendicular to the axis the surface mole- 
cules must do the same. Beyond this point the continued 
reversal of the small magnet indicates a continued reversal 
of the surface molecules. The complete reversal of the 
small magnet at the pole indicates a like reversal of the sur- 
face molecules. Thus the evolutions of the small magnet 
must indicate a like series of evolutions performed by the 
surface molecules of the large magnet. These, at the equa- 
tor, are reversely parallel to the axis ; at the pole they are 
diredtly parallel to the axis ; and at every intermediate point 
they are intermediate to these two positions. 
But this similarity of every magnet to the earth leads us 
to apply the same dedu(5tion to both cases. An interior dip 
like that we have supposed to exist in the earth must like- 
wise exist in every magnet in which it is not counterbalanced 
by terrestrial influence. Thus each magnet must virtually 
comprise two magnetic vortices, whose centres of rotation 
lie beneath the point of vertical dip, while their superficial 
curves are separated by a neutral equatorial region. And 
these two vortices are comprised within a single vortex, 
which is indicated by the fixed direction of the magnetism 
of the axis and its complete reversion in the surface of the 
mass. 
This general vortex we can see, by the aid of iron filings, 
extending itself in significant lines from the equator to the 
poles of the magnet. The iron filings virtually become fluid 
