For the purpose of defraying extraordinary expenditures the state may contract public debts (but such debts shall never in the aggregate exceed one hundred thousand dollars). Every such debt shall be authorized by law, for some purpose or purposes to be distinctly specified therein; and the vote of a majority of all the members elected to each house, to be taken by yeas and nays, shall be necessary to the passage of such law; and every such law shall provide for levying an annual tax sufficient to pay the annual interest of such debt and the principal within five years from the passage of such law, and shall specially appropriate the proceeds of such taxes to the payment of such principal and interest; and such appropriation shall not be repealed, nor the taxes be postponed or diminished, until the principal and interest of such debt shall have been wholly paid.