Diary of John Quincy Adams, volume 2
Had the whole day to myself; as I did not attend the afternoon recitation. Spent my Time in reading Ferguson, and Saunderson.1
Nicholas Saunderson, The Elements of Algebra, In Ten Books..., 2 vols., Cambridge, England, 1740 (Harvard, Catalogus Bibliothecae, 1790, p. 1). JQA may have used his personal copy of Saunderson, recorded among his books in 1784, which is no longer in his or the other Adams' libraries ([Christian Lotter], Inventory of JQA's books, 6 Nov. 1784, Adams Papers).