1 882.] The Principles of Magnetism. 73 
would also constitute a mass of small magnets, which must 
arrange themselves under the same principle displayed by 
the magnetic molecules of masses, or the magnetic masses 
of the earth. Nature, in this particular, must repeat herself 
in the largest and the most minute masses. The mass of 
atoms must have a magnetic axis, and a magnetic equatorial 
surface with the poles of its atoms reverse to those of the 
axis, while all intermediate atoms must assume the neces- 
sary intermediate direction. A molecule, therefore, must be 
a counterpart of a spherical magnet, or of the earth, its 
magnetism, when undisturbed, exerting itself inwardly, and 
only displaying itself outwardly under strong exterior mag- 
netic influence. Whatever the arrangement of these mag- 
netic atoms, and the degree to which their dual energy is 
masked by their interior relations, they must be susceptible 
to exterior influences, and this magnetism may be usually 
made to display itself outwardly. If a magnet of sufficient 
energy be brought near to masses of such molecules, they 
Mill, in the majority of cases, display some degree of mag- 
netic force, precisely as two magnets do when brought close 
together. This magnetism is induced, and usually disap- 
pears on removal of the magnet. Nor is its origin difficult 
to comprehend under our hypothesis. For the magnets in 
any homogeneous aggregate must, when free from exterior 
attractions, feel only each other’s influence, and so arrange 
themselves as to exert all their force inwardly. But on the 
approach of an exterior magnet this arrangement is dis- 
turbed. The magnets seek to shift the directions of their 
axis so that a portion of their polar energy can be exerted 
in the direction of the external magnet. But this magnetic 
aCtion must be conveyed from molecule to molecule, and, 
where these are too far apart to readily aCt upon each other’s 
magnetism, only a very vigorous external force can produce 
a general accordance. Where they are close together, or 
for any other reason easily yield to each other’s influence, 
they must more readily obey the energy of external mag- 
netic attraction, and with the greatest readiness in the line 
of greatest approximation of molecules. It need scarcely 
be said here that the faCts of magnetism agree with the 
above deductions, magnetic substances, with few exceptions, 
being those whose molecules are closest together, while 
crystals are most strongly magnetic in their axis of greatest 
density. In certain cases the magnetism thus induced be- 
comes permanent, the molecules as magnets continuing to 
affeCt each other magnetically, and their conjoined mag- 
netism displaying itself outwardly. Thus the aCtion of 
VOL. IV. (THIRD SERIES). G 
