French physicist known for his theory that matter has the properties of both particles and waves. ALS in French, signed “Louis de Broglie,” one page both sides, 4.75 x 3.5, Institut de France, Academie des Sciences letterhead, November 23, 1959. Letter to a gentleman regarding an article commemorating the 100th anniversary of Max Planck’s birth. In fine condition, with the faint pencil notation “1959” in another hand above the date. R&R COA.
