Newnham was a surgeon-apothecary, the profession which was the forerunner of the general practitioner. Moreover, he was an example of an English surgeon-apothecary who was in medical practice before 1 August 1815 and was therefore exempt from the requirements of the 1815 Apothecaries Act: that controversial Act obliged all newly qualified surgeon-apothecaries to be licensed by the Worshipful Society of Apothecaries. Newham practised medicine in Farnham, Surrey, for sixteen years before obtaining a licence. He later became a strong supporter of the Provincial Medical and Surgical Association (from 1855 the British Medical Association) and in particular its Benevolent Fund for the relief of distressed medical men and their families. The present portrait was commissioned by subscribers to the fund on his retirement in 1857.