High speed photography has been used to study the compression of a deuterium plasma by an axial magnetic field generated by a wide single-turn coil. In this experiment the inductance of the coil is small compared with that of the external condenser bank so that the plasma implodes at a constant acceleration of 5 × 1012 cms/sec2. Flutes which develop on the outer surface of the plasma are interpreted as magnetohydrodynamic Rayleigh-Taylor instabilities produced by the inward acceleration of the interface separating magnetic field and plasma. The observed growth rates are in agreement with simple theory. It is shown that the ratio of the diffusivities of magnetic field and momentum determines whether the plasma resistivity or its viscosity is the dominant mechanism for damping the short wavelength instabilities. At the temperature and densities of this experiment the resistivity is primarily responsible for the damping and the wavelength of "maximum instability" calculated on this basis agrees with the observed value.