Any person or corporation, having knowingly received and accepted the benefits or any part thereof, of any conveyance, mortgage or contract relating to real estate shall be concluded thereby and estopped to deny the validity of such conveyance, mortgage or contract, or the power or authority to make and execute the same, except on the ground of fraud; but this section shall not apply to minors or persons of unsound mind who pay or tender back the amount of such benefit received by themselves.
R.L.1910, § 1150.