13. Notwithstanding anything contained in any other law for the time being in force, every person who, at a sale for the recovery of arrears of land-revenue or any other public demand, purchases any land or property, or any right or interest in land or property, which contains, or in which is situated an antiquity in respect of which an agreement under section 12 subsists, and every person claiming any title to any antiquity from, through or under an owner who entered into such agreement, shall be bound by such agreement.