 He became for a time a disciple of Berkeley's, and exchanged many letters with the philosopher over the years, discussing Berkeley's idealist philosophy.Before Berkeley left America in September 1731, Johnson convinced Berkeley to donate to Yale a large number of books, 500 pounds sterling, and a 100-acre farm with 100 pound sterling yearly income which would fund three scholars at the college.Johnson published the essay "An Introduction to the Study of Philosophy, exhibiting a General view of all the Arts and Sciences” in the May 1731 issue of London-based periodical "The Present State of the Republick of Letters" (1728–36).