Although Barlow is best known for his original researches on infantile scurvy, there is very little material relating to that subject in the collection. There are manuscript drafts of his address to the Royal Medical Society of Edinburgh and his Bradshaw Lecture on infantile scurvy (BAR/E1-2), but the bulk of the clinical and scientific component of the papers relates to other matters, particularly Raynaud's disease and erythromelalgia, diseases to which Barlow turned his attention later in his career.
Among Barlow's clinical papers is a notebook recording minutes of a 'Clinical Club', 1875-77 (BAR/D.2), whose members included, apart from Barlow himself, Sidney Coupland, Rickman Godlee, William Smith Greenfield, Robert Parker, and William Allen Sturge.
Most of Barlow's private patients' records have not survived, though there is an index to his private patients' books, covering the years 1876-1918 (BAR/F.1).
Scientific and clinical matters are also discussed in Barlow's correspondence, but again this is relatively thin for the period when he was active in research. Barlow's non-family correspondence has clearly been heavily weeded: there are few letters from patients, with the exception of some prominent individuals, such as Mary Curzon, wife of Lord Curzon, Randall Davidson, archbishop of Canterbury, Lord Salisbury and Lord Selborne, and in general it seems that while letters from important or well-known figures have survived those from individuals deemed less important have been discarded. Significant numbers of letters remain however from several of Barlow's regular correspondents, such as the poet, Robert Bridges, Lord Bryce, and William Page Roberts, dean of Salisbury, as well as medical figures like Sir William Jenner and Sir James Reid.
Barlow's personal papers and family correspondence have survived in bulk and form a rich source of material for both his private and family life, and his public career. There are travel journals and sketchbooks from his earlier years, mainly documenting visits to the Continent, 1869-83; correspondence with his parents, brother, wife and children, 1852-1940, including letters written by Barlow from Balmoral, where he served as royal physician intermittently between 1897 and 1899, an eye-witness account of the death of Queen Victoria in 1901 (BAR/B.2/4), and letters and telegrams from court in 1902 during the crisis of Edward VII's appendectomy; and commonplace and scrapbooks compiled in retirement, 1920-37. Also from this period are various temperance notes and addresses.
The archive also comprises letters and papers of Barlow's parents, 1842-87; of Barlow's wife, Ada, including letters from her brother and sisters in India, 1858-80, and to her daughter Helen studying in Darmstadt, Germany, 1905-6; of Barlow's sons, Alan, Thomas and Basil, including letters from the last-named while serving on the Western Front, 1916-17; and notably of his daughter Helen, including correspondence with Archbishop and Mrs (later Lady) Davidson, 1910-35, and letters from Sir John Rose Bradford and his wife while serving in the Royal Army Medical Corps in France, 1914-19. Helen Barlow's papers also include records of three charities with which she was associated: the University College Hospital Ladies Association, 1900-50, the Southwark Boys Aid Association, 1914-36, and the Quinn Square [Southwark] Social Centre Society, c. 1935-1951. Finally there is a handful of letters to Andrew Barlow, Sir Thomas's grandson, mainly relating to articles he wrote about his grandfather, 1955-81.
