  We present in this continuation paper a new axiomatic derivation of the
Schr\"odinger equation from three basic postulates. This new derivation sheds
some light on the thermodynamic character of the quantum formalism. We also
show the formal connection between this derivation and the one previously done
by other means. Some considerations about metaestability are also drawn. We
return to an example previously developed to show how the connection between
both derivations works.
