8. Purchasers at certain sales and persons claiming through owner bound by instrument executed by owner.

Every person who purchases, at a sale for arrears of land revenue or any other public demand, an estate or tenure in which is situated a monument in respect of which any instrument has been executed by the owner for the time being, under section 4 or section 5, and every person claiming any title to monument from, through or under an owner who executed any such instrument, shall be bound by such instrument.