The scanty leisure of a busy professional life was devoted to botany, and Hailstone became known as the leading authority on the flora of Yorkshire.
261-5, 549-53), and a list of rare plants to Thomas Dunham Whitaker's History of Craven (1812, pp. 509–19).
His valuable herbarium was presented by his sons to the Yorkshire Philosophical Society, and is now in the museum at York.
He died at Horton Hall, Bradford, on 26 December 1851, aged 83, leaving two sons, John, a clergyman, and Edward.
[1] Edward (1818–90) succeeded his father as solicitor at Bradford, and finally retired to Walton Hall, near Wakefield, where he accumulated a remarkable collection of antiquities and books, among them the most extensive series of works relating to Yorkshire ever brought together, which he left to the library of the dean and chapter, York.