[1] He began his medical education as a pupil of Kinder Wood[3] in Manchester (where he used to attend John Dalton's lectures on chemistry), and in 1821 went to Edinburgh to continue his studies there.

[4] Although his merits in this matter have sometimes been denied, his claim to the title Father of Ovariotomy is now generally conceded, and it is admitted that he deserves the credit not only of having shown how that operation could be made a success, but also of having played an important part in the advance of abdominal surgery for which the 19th century was conspicuous.

[1] A number of manuscripts previously owned by Clay are held by Special Collections at the University of Manchester and include a record of some of the ovariotomy (oophorectomy) operations he performed between 1855 and 1869.

[5] In spite of the claims of a heavy practice, Clay found time for the pursuit of geology and archaeology.

Among the books of which he was the author were a volume of Geological Sketches of Manchester (1839) and a History of the Currency of the Isle of Man (1849), and his collections included over a thousand editions of the Old and New Testaments and a remarkably complete series of the silver and copper coins of the United States.