In case any person having any estate in or charge or security on the land to be improved shall within the month named in the last preceding section signify in writing to the Commissioners his dissent from such application, stating therein the nature of his estate in or charge or security on such land the Commissioners shall certify such dissent to the landowner by whom the application was made, and shall not make any provisional or other order sanctioning the improvements unless or until such dissent be withdrawn, or an order be made . . . F2 by the Court of Session in Scotland, in manner herein-after provided, authorizing the Commissioners to sanction the same; nor shall they make any provisional or other order sanctioning the improvement of any land in the case of which the landowner, or the husband of the landowner, shall be the father of the person or persons entitled either at law or in equity to any estate in such land, or any part thereof, in reversion or remainder, up to and inclusive of the person entitled to the first vested estate of inheritance, and such person or persons, or any of them, shall be [F3 a person under legal disability by reason of nonage], unless or until such an order as herein-before mentioned shall be made by such Court as aforesaid.