  Analytical expressions for the magnetization and the longitudinal
conductivity of nanowires are derived in a magnetic field, B. We show that the
interplay between size and magnetic field energy-level quantizations manifests
itself through novel magnetic quantum oscillations in metallic nanowires. There
are three characteristic frequencies of de Haas-van Alphen (dHvA) and
Shubnikov-de Haas (SdH) oscillations, F=F_0,F_1, and F_2 in contrast with a
single frequency F'_0 in simple bulk metals. The amplitude of oscillations is
strongly enhanced in some "magic" magnetic fields. The wire cross-section S can
be measured along with the Fermi surface cross-section, S_F.
