Section 7
SEC. 7. An employer who shall have contributed to an insurance fund created and maintained for the mutual purpose of indemnifying an employee for personal injuries for which compensation may be recovered under the provisions of this Act or who shall have contributed to any relief society for the same purpose may prove in mitigation of the damages recoverable by an employee under the provisions of this Act such proportion of the pecuniary benefit' which has been received by such employee from any fund or society on account of such contribution of said employer as the eh employer to such fund or society bears to the m thereto.