Hendrik Anthony Kramers (1894-1952) was appointed Ehrenfest's successor in Leiden in 1934. The name invites comparison with Hendrik Antoon Lorentz, whom Ehrenfest had succeeded twenty years earlier. Undoubtedly, Lorentz was the greater physicist and the influence of his work has been more profound and enduring than that of Kramers, but Kramers's interests covered a wider field. Lorentz confined his activities to the field of physics: "The physicist must restrict himself to reading in his way in the book of the world", he says in one of his many popular addresses. It is unthinkable that Lorentz would have put a copy of Baudelaire's Les Fleurs du Mal among his physics books, like Kramers did, with the motivation that its spirit was somehow akin to that of theoretical physics. Neither does one imagine Lorentz spending time on writing a beautiful Dutch translation of Mallarmé's Les Fenêtres. Kramers did; it was one of his favorite poems and I still remember how, during the war years, he referrred to the confiscation of laboratory equipment by the German occupying forces as "Le Vomissement impur de la Bêtise" (Stupidity's impure vomiting).
H.B.G. Casimir, Haphazard Reality (Harper & Row, New York, 1983)