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INTRODUCTION to AGRICULTURAL BIO-CHEMISTRY BY R. ADAMS DUTCHER, CLIFFORD 0. JENSEN,and PAUL M. ALTHOUSE; all at The Pennsylvania State College.Covers general introductory material, plant growth, and animalgrowth, and includes such important topics as farm chemurgy,pesticides, biological oxidations, and the nutritional requirements ofhumans and domestic animals. Although this volume follows thegeneral plan outlined in the Dutcher-Haley Introduction to Agri-cultural Biochemistry, it is in reality a new book since all the chaptersbut one have been completely revised and rewritten. January 19 5 1.502 pages. Illus. Prob. $6.00.

APPLIED NUCLEAR PHYSICS Second Edition. ByERNEST POLLARD, Yale University, and WILLIAM L. DAVIDSON,B. F. Goodrich Company. This book has been expanded to includethe progress in the field since 1942. It gives a clear picture of prac-tically all phases of nuclear physics including the basic facts ofnuclear particles and radiations, methods of accelerating them, trans-mutation, natural and artificial radioactivity, isotopy, and nuclearfission. Applied Nuclear Physics seeks to provide enough detail sothat the reader can "apply the techniques of nuclear physics to re-search problems with some facility." December 1950. 352 pages.Illus. $5.00.

METHODS of OPERATIONS RESEARCH By PHILIPM. MORSE, The Massachusetts Institute of Technology, and GEORGEE. KIMBALL, Columbia University. Based on secret war work, thisbook sets up the subject as a true applied science-useful in any fieldwhere operations are numerous, fairly simple, and roughly similar.The book carefully defines the subject, shows its limitations, de-scribes the scientific tools used, and gives the setup of an operationsresearch group. It was written for the worker in the field and forthe executive interested in establishing operations research in hisorganization. A TECHNOLOGY PRESS BOOK, M.I.T. January 1951.160 pages. Illus. Prob. $4.00.

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HOTEL RESERVATIONS117th AAAS MEETINGCleveland, December 26-30, 1950

The list of hotels and the reservation coupon below are for your convenience inmaking your hotel room reservation in Cleveland. Please send your application, notto any hotel directly, but to the Housing Bureau of the Cleveland Convention andVisitors' Bureau to avoid delay and confusion. The experienced Housing Bureau willmake assignments promptly and the hotel will send a confirmation directly to you intwo weeks or less. Please plan to share a room with a colleague. In addition toeconomy, this will insure. ample accommodations for all in the downtown hotels. Mailyour application now to secure your first choice of desired accommodations.

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