357 
1921-22.] Sir Alfred Ewing’s Magnetic Atom. 
respectively, will place itself as shown in hg. 3. On the approach of 
another atom on which a similarly placed magnetic electron existed in the 
outer shell, they would both swing through 90° to take up a new stable 
position, thus requiring work to be done and energy dissipated on both 
atoms. Both these electrons are already held each to their own atom by 
the attraction of the positive nucleus, and, in addition, they are now 
attracted to each other magnetically, so that we seem to have here all the 
conditions required for the chemical combination of two elements. In the 
first place, a definite amount of work is done by each atom on their close 
approach to each other in swinging the two magnetic electrons to the 
angle of instability. In the second place, that work is dissipated as heat 
as the two magnetic electrons swing irreversibly into their new stable 
position. In the third place, the two atoms may be supposed to remain 
attracted and held together by the combination ot* electrostatic and 
magnetic attraction which is brought into play. 
So far we have only dealt with purely diagrammatic arrangements 
of magnets in one plane, and it is necessary to see whether we can arrive 
at similar results if we assume groups of magnetic electrons moving in 
small orbits, and arranged on a series of shells round the positive nucleus. 
If the atom is purely electrostatic, Sir J. J. Tiiomson lias shown that 
there cannot be more than eight electrons in each shell if the positive 
nucleus has just a sufficient charge to neutralise the negative charges 
on the electrons, but if the electrons have also got magnetic properties 
they will attract each other, and, consequently, the numbers in each shell 
and the charge on the positive nucleus can be increased. 
