Copy letter from Herbert Rix, to the Editors of "The Physical Review", Cornell University, Ithaca, New York 'Dear Sirs, In October of last year you offered to exchange the "Physical Review" for the "Proceedings of the Royal Society". I write now by instruction of the Library Committee to say that if that offer still stands, the Society will be pleased to make the exchange. I am, yours truly, H. RIX Asst. Sec. R.S. [Assistant Secretary, Royal Society]'. 31 July 1894