If within 30 days
after the interest accruing upon any such mortgage has become payable and
after demand thereof in writing the same be not paid the mortgagee may without
prejudice to his right to sue for the interest so in arrear in any court of
law or equity require the appointment of a receiver by an application to be
made as hereinafter provided and if within 6 months after the principal money
owing upon any such mortgage has become payable and after demand thereof in
writing the same be not paid the mortgagee without prejudice to his right to
sue for such principal money together with all arrears of interest in any
court of law or equity may require the appointment of a receiver by an
application to be made as hereinafter provided.