Where such inquiry shall relate to the value of lands to be purchased, and also to compensation claimed for injury done or to be done to the lands held therewith, the jury shall deliver their verdict, by a majority of their number, separately for the sum of money to be paid for the purchase of the lands required for the works, or of any interest therein belonging to the party with whom the question of disputed compensation shall have arisen, or which under the provisions herein contained such party is entitled to sell or convey, and for the sum of money to be paid by way of compensation for the damage, if any, to be sustained by the owner of the lands by reason of severing of the lands taken from the other lands of such owner, or otherwise injuriously affecting such lands by the exercise of the powers of this or the special Act, or any Act incorporated therewith: Provided always, that if the parties agree to dispense with such separation in the verdict may be returned for one sum.