  We present a new method of obtaining nonlinear integral equations
characterizing the thermodynamics of one-dimensional multi-component gases
interacting via a delta-function potential. In the case of the repulsive
two-component Bose gas we obtain a simple system of two NLIE allowing for an
efficient numerical implementation in contrast with the infinite number of
coupled equations obtained by employing the Thermodynamic Bethe Ansatz. Our
technique makes use of the Quantum Transfer Matrix and the fact that in a
certain continuum limit multi-component gases can be obtained from appropriate
anisotropic spin chains.
