[1] This early family interest in photography when it was still in its infancy was undoubtedly a major stimulus to the photographic career of Thomas Keith which began some eight years after the expedition of his father and brother to the Holy Land.

This appointment was to last for fifteen months and it was during this time that he learned from Syme the principles of surgery which were to form the basis of his future success.

Keith was succeeded as house surgeon by the young Joseph Lister, and the two remained friends for life.

Before starting in practice in Edinburgh, Keith spent two years in Turin as a surgeon to a family friend, the Hon Ralph Abercromby, British resident minister (ambassador) at the Court of Victor Emmanuel II, the King of Sardinia (and later first King of a united Italy).

On 4 November 1847, Simpson with George Keith and his other assistant James Mathews Duncan (1826–1890), (another photographic enthusiast), conducted the famous experiment at 52 Queen Street, Edinburgh during which the trio discovered the anaesthetic effects of chloroform.

[8][9] Thomas Keith came to specialise in gynaecology and in 1862 performed his first ovariotomy (excision of ovarian cyst) but in the years 1853–56 he devoted much of his time to photography.

In his photography Thomas Keith used the waxed paper process developed by Gustave Le Gray (1820-1884), which he simplified and improved.

Because of the pressures inflicted by his medical practice, Keith did not continue with photography after 1856, but by this time he had created a priceless photographic record of nineteenth-century Edinburgh and images of Dysart in Fife and Iona.

Bell's successor in Edinburgh John Lizars (1787–1860), was sent McDowell's account and he performed the first successful ovariotomy in Britain, publishing the results in 1825.

[21] Keith further reduced the mortality rate to 4% when he began to use antiseptic technique, taught to him by his lifelong friend Joseph Lister.

His reputation was such that he was consulted by eminent people such as Lady Randolph Churchill (1854-1921), but his years here were dogged by ill health.

[3] He attributed some of his health problems to the large quantities of bicarbonate which he took to combat the condition and his repeated exposure to antiseptic agents may also have been a factor in his death at the age of 67.

On 4 June 1854 he had married Elizabeth Johnston, first cousin to Jessie (née Grindlay) wife of Sir James Young Simpson, and they had had six children, all of whom survived him.