The chapters on The Chemistry of Coffee and The Pharmacology of Coffee have been prepared under the author's direction by Charles W. Trigg, industrial fellow of the Mellon Institute of Industrial Research. The author wishes to acknowledge, with thanks, valuable assistance and numerous courtesies by the officials of the following institutions: British Museum, and Guildhall Museum, London; Bibliotheque Nationale, Paris; Congressional Library, Washington; New York Public Library, Metropolitan Museum of Art, and New York Historical Society, New York; Boston Public Library, and Boston Museum of Fine Arts; Smithsonian Institution, Washington; State Historical Museum, Madison, Wis.; Maine Historical Society, Portland; Chicago Historical Society; New Jersey Historical Society, Newark; Harvard University Library; Essex Institute, Salem, Mass.; Peabody Institute, Baltimore. Thanks and appreciation are due also to: Charles James Jackson, London, for permission to quote from his _Illustrated History of English Plate_; Francis Hill Bigelow, author; and The Macmillan Company, publishers, for permission to reproduce illustrations from _Historic Silver of the Colonies_; H.G. Dwight, author; and Charles Scribner's Sons, publishers, for permission to quote from _Constantinople, Old and New_, and from the article on "Turkish Coffee Houses" in _Scribner's Magazine_; Walter G. Peter, Washington, D.C., for permission to photograph and reproduce pictures of articles in the Peter collection at the United States National Museum; Mary P. Hamlin and George Arliss, authors, and George C. Tyler, producer, for permission to reproduce the Exchange coffee-house setting of the first act of _Hamilton_; Judge A.T. Clearwater, Kingston N.Y.; R.T. Haines Halsey, and Francis P. Garvan, New York, for permission to publish pictures of historic silver coffee pots in their several collections; The secretaries of the American Chambers of Commerce in London, Paris, and Berlin; Charles Cooper, London, for his splendid co-operation and for his special contribution to chapter XXXV; Alonzo H. De Graff, London, for his invaluable aid and unflagging zeal in directing the London researches; To the Coffee Trade Association, London, for assistance rendered; To G.J. Lethem, London, for his translations from the Arabic; Geoffrey Sephton, Vienna, for his nice co-operation; L.P. de Bussy of the Koloniaal Institute, Amsterdam, Holland, for assistance rendered; Burton Holmes and Blendon R. Campbell, New York, for courtesies; John Cotton Dana, Newark, N.J., for assistance rendered; Charles H. Barnes, Medford, Mass., for permission to publish the photograph of Peregrine White's Mayflower mortar and pestle; Andrew L. Winton, Ph.D., Wilton, Conn., for permission to quote from his _The Microscopy of Vegetable Foods_ in the chapter on The Microscopy of Coffee and to reprint Prof. J. Moeller's and Tschirch and Oesterle's drawings;