An expression is derived for the specific-inductive-capacitance tensor of an inhomogeneous plasma contained by a constant magnetic field. In calculating the tensor, attention is directed mainly to a calculation of the effects associated with drift movements of the plasma particles, effects which are important for waves with a very small phase velocity (that is, of the same order as the velocity of the drift movements). It is suggested that a calculation of the tensor, once and for all, would be highly useful for calculating the oscillations and the stability of an inhomogeneous plasma as one would then only have to solve Maxwell's equations; a solution of the charge-movement equations for each separate case would be avoided. The dielectric tensor is' calculated for a plasma in "plane geometry"; in other words, the lines of force of the magnetic field are assumed to be straight and parallel to one another. An imaginary gravitational field is introduced in order to obtain a qualitative evaluation of the curvature of the lines of force. It is assumed that the equilibriumvalue gradients and the gravitational field are sufficiently small and perpendicular to the magnetic field. The oscillation frequency is considered to be large compared with particle-collision frequency.Vlasov's kinetic equation is used in deriving the expression for the tensor. The equilibrium state of each type of plasma charge is characterized by an arbitrary function of the centres of Larmor circles. Wave frequency is assumed to be arbitrary in relation to the cyclotron frequency of all the particles considered, and, similarly, the wavelength is considered arbitrary in relation to the Larmor radius of the particles (but less than the dimensions of the inhomogeneity of the plasma). The direction of the wave vector is taken to be arbitrary in relation to the direction of the magnetic field and the inhomogeneity of the plasma. Both the macroscopic (Larmor) drift speeds of the c ∇ p/enH type and the microscopic drifts (diamagnetic, gravitational and electrical) of individual particles are taken into account. Calculation of the diamagnetic drift, in particular, which is related to the magnetic-field gradient, makes it possible to deal with problems of plasma oscillation not only for low-pressure systems (β ≡ 8 π p/H2 ≪ 1) but for high-pressure systems as well (β ≈ 1).The case of a low-pressure plasma (β ≪ 1) without equilibrium electrical and gravitational fields—that is, a system in which only the effects of Larmor drift are important—is considered in detail. For this case a simpler expression has been derived for the dielectric tensor as well as an equation describing vox'tex-free oscillations of arbitrary frequency.Special attention is given to low-frequency waves (with a frequency lower than the ion cyclotron frequency) directed almost perpendicularly to the magnetic field. Dispersion equations have been derived for the Alfvén and ion-acoustic waves modified by drift movements, in an inhomogeneous plasma. These waves are unstable and their buildup may endanger the success of experiments in containing plasma.