This paper is concerned with the linear theory of ereditary electromagnetism. The second law is stated through the Clausius
property for approximately-cyclic processes and by considering sinusoidal electromagnetic fields, the necessary and sufficient
conditions for its validity have been obtained.
Lavoro eseguito nell'ambito delle attività di ricerca del G.N.F.M. del C.N.R. e dei progetti 40% e 60% del M.P.I.