Sizov, I.A. (1956, 1 letter) Skottsberg, Dr. Carl (1949–1957, 34 letters) Slossen, Mrs. L.B. (1954, 1 letter) Smith, Dr. A.C. (1949–1957, 20 letters) Smith, Dr. H.H. (1948, 3 letters) Smith, Hubert L. (1955, 2 letters) Smith, Dr. Lyman B. (1941–1949, 6 letters) Smith, Malcolm G. (1956–1957, 2 letters) Smith, Marguerite Black (1949, 1 letter) Smith, Raymond R. Jr. (1951, 1 letter) Smith, (?) (1950, 1 letter) Smythe, Alice R. (1950, 1 letter) Snell, Dr. Walter h. (1948, 3 letters) Snow, Sidney (1952, 2 letters) Soukup, Dr. J. (1956, 1 letter) Sowers, Roy V. (1954, 2 letters) Spalding, George H. (1949–1950, 8 letters) Spencer, Elizabeth R. (1953, 2 letters) Sproul, Robert G. (1925–1957. 37 letters)