All Debts and Liabilities legally charged upon or payable out of any Rates or Assessments authorized to be levied or made under any Act relating to the paving, lighting, watering, cleansing, or improving of any Parish in either of the Schedules (A.) and (B.) to this Act, or any Part of any such Parish, shall be charged upon the Rates (other than those to be raised for defraying Expenses of Sewerage, and (where separate Rates are made under this Act for defraying Expenses of lighting) Expenses of lighting,) to be raised under this Act in such Parish or Part, and the several District Boards and Vestries shall cause the Sums necessary for discharging such Debts and Liabilities to be raised in their respective Districts and Parishes accordingly; and such Boards and Vestries shall once in every Year set aside, out of the Rates charged under this Act with such Debts and Liabilities, such Sum as they think proper, not being less than such Per-centage as herein-after mentioned; that is to say, Three Pounds per Centum where the Amount of Principal Debt (exclusive of Annuities) does not exceed One Fourth of the rateable Value of the Property rateable for Payment thereof, and in other Cases Two Pounds per Centum on the Amount of the Principal Debt (exclusive of Annuities), for the Purpose of paying off such Principal, except where the Interest only of such Debt is charged upon such Rates or Assessments as aforesaid, and except also where any such Debt was contracted under the Authority of a Local Act, and the Local Act did not require that the Principal of such Debt should be paid off within a limited Time; and the Sums so from Time to Time set aside, and all Monies applied in augmentation thereof, and the Proceeds thereof respectively, shall be applied and dealt with, for the Purpose of paying off such Principal as aforesaid, in manner by this Act provided with respect to Sums set aside for the Purpose of providing a Fund for paying off Mortgages granted under this Act: Provided always, that where any Debts or Liabilities are charged on any Rates or Assessments not wholly levied or made in or upon any One Parish mentioned in Schedule (A.) to this Act, or any One District mentioned in Schedule (B.) to this Act, the Metropolitan Board of Works shall apportion such Debts and Liabilities between the respective Parishes and Districts in or upon which such Rates or Assessments are authorized to be levied or made, and shall certify to the District Board and Vestry respectively of every such District and Parish the Amount of the apportioned Part of such Debts and Liabilities to be discharged by Rates to be raised in such Parish or District, or any Part thereof, under this Act, and such apportioned Part shall be discharged accordingly: Provided also, that nothing in this Enactment shall affect the Right of any Creditor to require Payment of any such Debt as aforesaid within any less Time than is prescribed by this Enactment for the Payment thereof.