Thomas received his general education at the Grocers' Company's school at Hackney, and after matriculating at the London University entered the London Hospital as a student, taking the Buxton entrance scholarship. He later became prizeman in minor surgery. He qualified in 1906 and joined his brother, Mr D W F Lantham in general practice in Barnsbury. He became an ardent worker in the anti-tuberculosis cause in Islington, and was acting as secretary to the Islington Tuberculosis Dispensary and as honorary treasurer to the L.C.C. Islington Schools treatment centre, when he joined the R.A.M.C. in October 1914. He entered the war in France on 9th February 1915. Thomas was killed by a fragment of shell as he was going to the aid of a wounded soldier. His mother received a telegram of Royal sympathy. On of his officer wrote: "He was absolutely fearless under fire, and his treatment of the wounded was splendid." Another wrote: "He had a cheery word for everyone, and his loss will be felt by a large circle of friends." Thomas was the second son of Charles William Latham, M.R.C.S. and Georgina Eliza Price Latham of The Grange, Penn Rd., Holloway, London.