Relates largely to Academy administration and interests, as Ruschenberger was its president from 1869-1881, and actively concerned himself with its affairs for many years later. Included are letters from 107 well-known scientists, and biographical notes and reminiscences about others. Highlighted are R. M. Holbrook's reminiscences of Leidy, Ruschenberger's biographical sketches of Prof. Gabb, William Hembel, Mr. Schwann and H. A. Pilsbry and Wistar's deed of trust.