268 PROF. W. THOMSON ON THE MATHEMATICAL THEORY OF xMAGNETISM. 
tion of magnetism, although it has not, I believe, been noticed in any writings hitherto 
published on the mathematical theory of magnetism, is a subject of investigation of 
great interest, and, as I hope on a later occasion to have an opportunity of showing, 
of much consequence, on account of its maximum and minimum problems, which 
lead to demonstrations of important theorems in the solutions of inverse problems 
regarding magnetic distribution. 
