Every officer employed by the commissioners who shall . . . F1 accept on account of anything done by virtue of his office, or in relation to the matters to be done under this or the special Act, any fee or reward whatsoever, other than the salary or allowances allowed by the commissioners, or who shall be in anywise concerned or interested in any bargain or contract made by the commissioners shall be incapable of being afterwards employed by the commissioners, and shall forfeit the sum of fifty pounds, and any person may sue for such penalty by action on the case in any of the superior courts, and shall on recovery thereof be entitled to full costs of suit.