Entered the Army as a Surgeon's Mate on the Hospital Staff, not attached to a regiment, on July 8th, 1811, and on July 2nd, 1812, was commissioned as Hospital Mate for General Service. He became Assistant Surgeon to the 18th Foot on September 9th, 1813, and on November 1st, 1819, was transferred to the 6th Royal Veterinary Battalion; on December 25th, 1821, to the 3rd Royal Veterinary Battalion; and on March 25th, 1826, back to the 18th Foot. He was gazetted Surgeon to the 4th Foot on November 19th, 1830, was transferred to the 4th Dragoon Guards on December 6th, 1839, to the Staff (2nd Class) on October 3rd, 1848, and retired on half pay on December 22nd, 1848. He died at his residence, 7 Sumner Place, Onslow Square, on January 15th, 1874. Publication: Lewis published as his doctorial thesis:- *Quœdam de Dysenteria prout in Calidis Regionibus occurebat, complectens*, 8vo, Edinburgh, 1821.