Thomas Gisborne was admitted to St John's in 1744, and gained his BA in 1747, MA in 1751 and MD in 1758. He practised as a physician in St George's Hospital in London, before being admitted to the Royal College of Physicians, of which he later became president three times. During this time he was also physician to George III. At the time of his death he was senior fellow of St John's and left a large part of his library to the College, although all his medical books went to the library of the Royal College of Physicians.
Gisborne's collection is a typical example of the library of an 18th-century gentleman. It includes many contemporary editions of 18th-century fiction, drama, poetry and miscellanea. Typical items include:
The books from Gisborne's library are identifiable by a book label detailing his bequest to the College. Translated it reads:
Bequeathed by the will of Thomas Gisborne, M.D. R.& A.S.S. physician to the King and to the Royal family; former President of the Royal College of Physicians of London; and Fellow of this College for fifty-five years.
The books also constitute one of the few collections in the Upper Library which are, in the main, shelved together, in classes A/G and Aa/G. None bear his own inscription but several bear the inscription of his father, James Gisborne.