592. Revocation of patent by the comptroller on his own initiative.

If it appears to the comptroller1 that an invention for which a patent has been granted formed part of the state of the art only by reason of its comprising matter contained in an application for another patent published on or after the priority date2 of that invention3, he may on his own initiative by order revoke the patent, but must first notify the proprietor of the patent that it appears to him that the patent ought to be revoked and must give the proprietor opportunity, within three months of the notification, of making observations and of amending the