  We derive a boson Hamiltonian from a Nuclear Hamiltonian whose potential is
expanded in pairing multipoles and determine the fermion-boson mapping of
operators. We use a new method of bosonization based on the evaluation of the
partition function restricted to the bosonic composites of interest. By
rewriting the partition function so obtained in functional form we get the
euclidean action of the composite bosons from which we can derive the
Hamiltonian. Such a procedure respects all the fermion symmetries.
