General Correspondence General correspondence, [1843-1972], of Karl Pearson, consisting of letters mainly addressed to Pearson, including correspondence with his first wife, Maria Sharpe Pearson, and his children Egon Sharpe Pearson and Helga Sharpe Hacker (Ref: 624-906); letters from Karl Pearson (Ref: 907-931); closed medical correspondence and letters from unidentifiable correspondents (Ref: 932-933). 1843-1972