Mexico. (Great Britain). 1863. Envelope addressed to Mexico bearing Great Btitain SG 90, 1s green (2) tied Glasgow duplex endorsed 'Per French steamer' with circular 'PP' on face in red routed via London with octagonal French paquebot 'Mexique/ Floride' on reverse (Salles 1315) and charged with hand-struck '6' on face. Scarce item of French mailboat mail.