355 
1921-22.] Sir Alfred Ewing’s Magnetic Atom. 
poles of the first atom, and also, as the two atoms came very near, by the 
electrostatic repulsion of the electrons. It would cause the outer magnetic 
electron to oscillate about its centre, but if the repulsive forces Avere suffi- 
ciently strong it would not approach near enough to cause the little 
magnet to break away and swing into a new position of stability. If, how- 
ever, it was moving with sufficient momentum to approach sufficiently near to 
the little magnet, it would cause it to break away and then swing round into 
a new position, with the north pole to the south pole of the approaching 
atom. This operation would involve the doing of a definite amount of work 
to swing the little magnet into an unstable position, and the conversion of 
that amount of work into heat, when it falls into its new position. 
If we suppose the chemical reaction represented above to be the com- 
bination of two elements like potassium and chlorine to form a salt which 
a 
b 
Fig. 1. Fig. 2. 
ionises, then if the two atoms separate again we can suppose the second 
atom as carrying off the little magnet attached to it, thus depriving the 
first atom of an electron which will noAV be electropositive, while the 
second atom departing with an extra electron will be electronegative. 
This view of the nature of chemical combination also suggests a 
possible explanation of catalytic action ; for suppose, as before, one atom 
approaches another, and that while it can approach near enough to set one 
of the magnetic units swinging, it cannot approach near enough to swing 
it to the angle of instability, and Avhile this is going on another atom 
approaches at some angle to the first two atoms, it is evident that its 
approach may give the necessary additional magnetic force to swing the 
little magnet to the angle of instability, when it will then fall into a new 
position ; and if, while in the new position, it is draAvn nearer to the second 
atom under the magnetic attraction, it will remain permanently in the new 
position, while the catalysing atom will move away unaltered. 
Up to the present we have considered only one possible arrangement of 
