AMERICAN PHILOSOPHICAL SOCIETY HELD AT PHILADELPHIA, FOR PROMOTING USEFUL KNOWLEDGE THE LIBRARY-105 SOUTH FIFTH STREET, PHILADELPHIA, PENNSYLVANIA 19106 + Phone (2/5) a MArket 7.0706 -. Edward C. Carter, II Librarian April 29, 1981 Ms. Carolyn Kopp Archivist _ |, The Rockefeller Univ. ©) SL 1230 York Aves _ “ New York, N.Y. 10021 Dear Ms. Kopp: I am enclosing xerox copies of the Demerec items from the Chargaff Papers. This is compliments of the APS. Unfortunately I was unable to locate the Lederberg letters that you asked about. I think that I mentioned in an earlier letter to you that the Chargaff collection was arranged and sorted by people not employed by the Library and they did not arrange the collection as we treat our own collections. This is all to say that it is presently difficult to service the Chargaff Papers and unfortunately working by myself I do not have the time to sort through all of the folders more than once. If I have some time in the future I will give another look for the Lederberg letters, Sorry that I can not provide you with all that you asked for. Stephen Catlett s) anuscripts Libn. (ond Dongen knts OE Ae