Section 4 Parties interested may commute fish teinds by agreement.

In any parish in which there are fish teinds it shall be lawful for the minister of the parish, the presbytery, and the persons liable in payment of fish teinds, to enter into an agreement for the commutation or redemption of the fish teinds, and to contract for the substitution of a capital sum, to be raised and invested as herein-after provided.