§ 154. Separate accounts for lands purchased or mortgaged. The comptroller on application to him for that purpose, shall open an account in his office against any person, for a part or subdivision of a lot of land purchased from or mortgaged to the state, for the proportionate part of the moneys on any such part or subdivision, and thereafter give credit on the several parts or subdivisions, as the persons making payments may require. He may credit any prior payment to a part or subdivision, if such payment appears by satisfactory proof to have been originally intended to be paid on such part or subdivision or by or for the use of the person claiming the credit, whether so expressed in the receipts or not. No part of any such payments shall be applied to the reduction of the principal unpaid on any such part or subdivision, unless the payments exceed the interest, calculated on the principal due on such part, or subdivision, to the day when such part or subdivision is to be paid off, or a new account opened therefor. If separate receipts be given by the treasurer, for any payments which are claimed to be credited to the account of any such part or subdivision, the receipts shall be delivered to the comptroller and filed in his office. Separate accounts shall not be opened under this section unless a map and survey of the whole lot is filed with the comptroller, showing particularly the part or subdivision for which such account is to be opened, and satisfactory proof furnished the comptroller that the residue of the lot is sufficient security for the sum remaining unpaid thereon.