Section 28. That before making application for authority to borrow on loan, for a greater period than ninety days, any sum or sums of money, exceeding in amount the one-fifth part of the amount of taxes levied in the said district of Southwark, or the township of Moyamensing, the said commissioners shall publish in at least three of the daily papers published in the city of Philadelphia, twice in each week, for six months before the meeting of the Legislature, public notice of their intention so to apply for authority to contract such loan: Provided, however, That nothing contained in this act, shall be taken or construed to impair, or in anywise to alter or abridge the power and authority or the commissioners of the district of Southwark, or the commissioners of the township of Moyamensing, without the sanction and consent of the Legislature, to renew and to extend from time to time, as they may deem proper, the time of payment of the several loans already contracted, at the different periods of time at which they may severally become payable.