December 30, 1949, Vol. 110 7

APPLIED SEDIMENTATIONA SymposiumEdited by Parker D. Trask. A valuable new tool for geologists and engineers faced with thepractical problems of sedimentation. The book contains 35 original articles, each a comprehen-sive subject summarized by a specialist. The articles are grouped under these seven topics: basicprinciples of sedimentation; engineering problems involving strength of sediments; applicationsof processes of sedimentation; applications involving nature of constituents; economic mineraldeposits; petroleum geology problems; and military applications.Ready in March Approx. 674 pages Illus. Prob. $5.00

AN INTRODUCTION TOLUMINESCENCE OF SOLIDSBy Humboldt W. Leverenz. A new book in the WILEY STRUCTURE OF MATTER SERIES, MariaGoeppert Mayer, Advisory Editor. The author describes phosphors in terms of preparation,compositions, structures, and physical characteristics, using specific examples to illustrate eachgeneral feature. The best present phosphors and their methods of application for use in "fluo-rescent lamps," cathode-ray tubes, electron microscopes, "radium dials," nuclear particle count-ers, and x-ray fluoroscope screens are covered.Ready in January 569 pages Illus. Prob. $10.00

SELECTED INVERTEBRATE TYPESEdited by F. A. Brown, Jr. A new kind of laboratory guide to the study of the anatomy andphysiology of common American invertebrate animals. The approximately 100 commonly usedAmerican species covered in the book include the most widely studied fresh water forms, organ-ized on a classificatory basis. The book features selected bibliographies at the end of each sectionand 235 illustrations, many of them original and drawn from the actual specimens. The entiremanual emphasizes information rather than directions.Ready in January Approx. 611 pages 235 illus. Prob. $6.00

ORGANIZATION OF BEHAVIORA Neuropsychological TheoryBy Donald 0. Hebb. This volume introduces the WILEY BOOKS IN CLINICAL PSYCHOLOGY.The author offers an original new theory to explain what takes place in the human brain betweenthe arrival of an excitation at a sensory projection area and its departure from the motor areaof the cortex. The first five chapters explain problems of studying behavior and develop a theoryto solve these problems. The theory is then applied to various types of behavior.November 1949 335 pages Illustrated $4.00

December 30, 1949, Vol. 110 SCIENCE 7

8 SCIENCE December 30, 1949, VoL 110

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SCIENCE December 30, 1949, Vol. 1108

December 30, 1949, Vol. 110 SCIENCE

Something extra in pH precision!The new Macbeth Shielded Micro-Elec-

The Macbeth Titration-pH Meter, finest instrument of its trodes are now available, completetype, permits accurate pH reading as fine as .03pH. This with stand and 5 ML beaker. Samplesis possible because a variable sensitivity control allows as small as 3 ML may be accuratelyadjusting the range of the meter between approximately measured.240mv and 3.7v and a bucking potentiometer permits ad-justing potential between plus 0.75v and minus 0.75v, inorder to shift scale to the right or left. By simple calibra-*tion, the titration scale may be employed to read pHValueS WrUun e us__erF.vMma_spreaAtan_1exrm.y..................................> sin:ai>.:':::;^g>.<: ~values, enabin the user to spread an extremely smalrange of pH over the entire scale, thus resulting in pHreadings as small as .03pH.Completely separate pH and Titration controls and elec-trode systems make possible concurrent pH measurements

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December 30, 1949, Vol. 110

Personnel Placement

POSITIONS WANTED

Biochemist: Ph.D. Columbia University 1950. Experience instable and radioactive tracers, synthesis, carbohydrate metabolism.Three years teaching experience. Desires research or teachingposition. Age 29. Married. Box 399, SCIENCE. X-

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Pharmaceutical Research Chemist: Good opportunity available fora man 30-40 who can demonstrate marked professional ability inthe development of new pharmaceutical products. Men with ex-perience in the manufacture of tablets, ampuls, liquids, ointments,and related products will be given preference. Initial appraisal ofrespondent will be based on completeness and content of resume ofacademic training, scope of experience, and evidence of possessingqualities as a leader. Position has good future with large mid-western pharmaceutical firm. Box 386, SCIENCE. 12/30

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Wanted: Hospital Biochemist: preferable with M.S. or Ph.D.,Supervise biochemistry laboratory in 280 bed hospital. Oppor-tunity for research. Reply: Dr. Roy Barnett, Norwalk Hospital,Norwalk, Conn. X

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IISCIENCEDecember 30, 1949, Vol. 110 11

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LIMNOLOGICAL ASPECTS OFWATER SUPPLY AND WASTE DISPOSAL

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12 SCIENCE December 30, 1949, Vol. 110

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