  The multiple scattering of high-energy particles in a thick target is
fromulated in an impact parameter representation. A formalism similar but not
identical to that of Moliere is obtained. We show that calculations of particle
beam broadening due to multiple Coulomb scattering alone can be given in closed
form. The focus of this study is on whether or not the broadening of the
Coulomb angular distribution prevents the retrieval of nuclear-interaction
information from mesauring the angular distributions of charged partiles
scattered from a thick target. For this purpose, we study multiple scatterings
with both the nuclear and Coulomb interactions included and we do not make a
small-angle expansion. Condition for retrieving nuclear infomration from
high-energy protons propagating through a block of material are obtained.
