Where, during the continuance of the possession taken under any such invalid lease as above mentioned, the person for the time being entitled (subject to such possession as aforesaid) to the property comprised in such lease, or to the possession thereof, is able to confirm such lease without variation, the lessee, the lessee's executors, or administrators (as the case may require), or any person who would have been bound by the lease if the same had been valid, shall, upon the request of the person so able to confirm the same, be bound to accept a confirmation accordingly; and such confirmation may be by memorandum or note in writing, signed by the persons confirming and accepting respectively, or by some other persons by them respectively thereunto lawfully authorised; and after confirmation and acceptance of confirmation such lease shall be valid, and shall be deemed to have had from the granting thereof the same effect as if the same had been originally valid.