Became a partner of Mr Hanbury in his practice in King Street, Westminster. This practice was of very old standing, and had at one time been carried on by Golding, father of that Golding who was Lord Clive's Secretary. Lavies was in active practice in Westminster for forty-seven years, moving from King Street to Great George Street, and thence to 34 Bessborough Street, South Belgravia, where he died in 1867. In addition to having a large private practice, he was Surgeon to the House of Correction, Westminster, the Royal Artillery Cavalry Barracks and the Household War Department, and the Emanuel Hospital, as well as Indoor Medical Officer to the United Parishes of St Margaret and St John. Lavies has been described as a sound practitioner frequently summoned in cases of difficulty. Of a most prepossessing appearance and of winning manners, he was a favourite with all. At the time of his death he was Vice-President of the Royal Medical Benevolent College, and was a prominent member of the British Medical Association from the time of its formation. He was President of the Medical Registration Association, being seldom absent from his post, subscribing largely to its funds, and making himself responsible for its debts. He died on October 26th, 1867, at his residence, 34 Bessborough Street, South Belgravia.