ISOTOPES IN BIOCHEMISTRY：HISTORICAL BACKGROUND＆By HANS T．CLARKE，Columbia University 3
SEPARATION OF STABLE ISOTOPES＆By HAROLD C．UREY，Institute for Nuclear Studies，University of Chicago 16
THE PREPARATION OF RADIOACTIVE ISOTOPES＆By GLENN T．SEABORG，University of California 43
RECENT DEVELOPMENTS IN THE AVAILABILITY OF ISOTOPES＆By PAUL C．AEBERSOLD，Chief of the Isotopes Branch，United States Atomic Energy Commission 56
THE DETECTION OF STABLE ISOTOPES＆By ALFRED O．NIER，University of Minnesota 80
FUNDAMENTAL PRINCIPLES OF THE DETECTION AND MEASUREMENT OF RADIOACTIVITY＆By CHARLES D．CORYELL，Massachusetts Institute of Technology 105
ASSAY OF RADIOACTIVE ISOTOPES IN BIOLOGICAL RESEARCH＆By MARTIN D．KAMEN，Washington University，St．Louis 141
PREPARATION OF COMPOUNDS CONTAINING ISOTOPES＆By DONALD B．MELVILLE，Cornell University Medical College 161
STUDIES ON THE METABOLISM OF PROTEINS＆By DAVID B．SPRINSON，Columbia University 182
THE USE OF ISOTOPES IN THE STUDY OF INTERMEDIARY CARBOHYDRATE METABOLISM＆By HARLAND G．WOOD，Western Reserve University 209
THE INTERMEDIARY METABOLISM OF LIPIDS＆By KONRAD BLOCH，University of Chicago 243
TRACER STUDIES ON THE METABOLISM OF MINERAL ELEMENTS WITH RADIOACTIVE ISOTOPES＆By DAVID M．GREENBERG，University of California Medical School 261
APPLICATION OF RADIOACTIVE IODINE TO STUDIES IN IODINE METABOLISM AND THYROID FUNCTION＆By I．L．CHAIKOFF and A．TAUROG，University of California 292
MEDICAL APPLICATIONS OF RADIOACTIVE TRACERS＆By JOSEPH G．HAMILTON，University of California 327
THERAPEUTIC USE OF RADIOPHOSPHORUS IN POLYCYTHEMIA VERA，LEUKEMIA，AND ALLIED DISEASES＆By BYRON E．HALL，Mayo Clinic，Rochester，Minnesota 353
TREATMENT OF THYROID DISEASE BY MEANS OF RADIOACTIVE IODINE＆By SAUL HERTZ，Harvard University 377
HEALTH HAZARDS IN THE USE OF RADIOACTIVE ISOTOPES＆By WILLIAM F．BALE，University of Rochester School of Medicine and Dentistry 395
MEASURES FOR THE PROTECTION OF PROPERTY AND PERSONNEL＆By JAMES J．NICKSON，Memorial Hospital，New York City 409
INTERNATIONAL ASPECTS OF ATOMIC ENERGY＆By HAROLD C．UREY，Institute for Nuclear Studies，University of Chicago 423
COMMENTS ON THE DEVELOPMENT OF ATOMIC ENERGY＆By FARRINGTON DANIELS，University of Wisconsin 433
PANEL DISCUSSIONS ON SPECIAL TOPICS 443