Physicians Charles H. (1865–1939) and William J. (1861–1939) worked together in the family’s medical practice, which eventually evolved into the famed Mayo Clinic in Rochester, Minnesota. Lot of two items: TLS, signed “C. H. Mayo,” one page, 7.75 x 10.5, personal letterhead, March 2, 1931. A letter to Roger Metcalf, who had expressed interest in becoming a doctor. In part: “It costs a good deal to go through the medical schools of the present day one can save a year’s time on the whole course…. The medical course takes in all branches of medicine and one does not specialize until after graduation. During your years of work after you have finished, or perhaps by the time you have finished your hospital internship, you may find you have a special liking for some particular branch of the work and then you can specialize in that.” Also included: TLS, signed “W. J. Mayo,” 7.75 x 10.5, personal letterhead, October 11, 1934. A letter to the same recipient as above. In part: “As a general thing, I think three years premedical work is sufficient…. If one is taking up clinical medicine, it is important to choose a medical school that lays stress on clinical training, and of these, Harvard and the University of Pennsylvania are excellent.” In fine condition, with usual mailing folds, a few spots of minor soiling, and mild, even toning. R&R COA.