Book excerpt: A simplification of the Chapman-Enskog method for the calculation of the electrical conductivity of a multicomponent partially ionized gas in a magnetic field is presented. The calculation requires the inversion of a matrix which is of the order of the approximation, and is independent of the number of species. The third approximation to the electrical conductivity is examined for an electron-ion-neutral plasma and the results are compared with those obtained from the mixture rules of Lin, Resler, and Kantrowitz, and of Frost. It is shown that within the uncertainties in the experimental electron-neutral cross- section values, Frost's formula offers a satisfactory method of calculation for most engineering applications.