  In addition to the E2/M1 ratio of the N->$\Delta$ transition, the
electromagnetic polarizabilities and spin-polarizabilities are important
structure constants of the nucleon which serve as sensitive tests of chiral
perturbation theory and of models of the nucleon. Recently, these quantities
have been investigated experimentally at MAMI (Mainz) by high-precision Compton
scattering using hydrogen and deuterium targets, where for the latter the
method of quasi-free scattering has been applied.
