The county commissioners, upon the order of the court of quarter sessions, or, in vacation, of a law judge thereof, in the exercise of its or his discretion, and upon such terms as the court or judge may impose, may discharge from prison, without the delay and expense of any proceedings under the insolvent laws of this Commonwealth, every convict who shall have served out his or her term of imprisonment, or who shall have been committed for nonpayment of costs only; or any person who shall have failed to comply with the order of the court of quarter sessions upon conviction of fornication or bastardy, or for fornication and bastardy, and been confined for a period of more than three months, notwithstanding if he be convicted and shall not have paid the costs of prosecution, fine, or made restitution, or paid the value of stolen goods or property, or failed to comply with the court's order upon conviction of fornication or bastardy, or fornication and bastardy: Provided, That, in the opinion of said commissioners, such person is unable to pay or restore the same; and, provided, that such discharge shall not prevent the Commonwealth, or any person interested in such payment or restitution, from proceeding by action to recover that same from the property of such person; but no such person shall be so discharged until he or she shall have made, under oath or affirmation, duplicate schedules of all his or her property, real, personal or mixed, so far as he or she can ascertain the same,--one of which shall be filed among the papers of the said prison, and the other with the clerk of the court of quarter sessions; Provided further, That nothing in said proceedings shall either add to or take from the liability of said county for costs, under existing laws of this Commonwealth.