Abstract
The partition sum (the diagonal element of the one-particle density matrix) of a gas of non-interacting boltzons in a random potential is calculated. It is shown that the author's formula for the averaged density matrix must be subject to a minor modification, being multiplied by a correction factor. A considerable simplification of the formula is achieved in a limiting case which was not dealt with previously but may be important enough if one has in mind electrons in amorphous semiconductors.