Mac 7 90 - Science · Mac 7 90 oL11SINE1 NewBooksandEditions PRINCIPLES of IONIC ORGANIC REACTIONS ByELLIOTR.ALEXANDER, University of Illinois. Presents the reaction mechanisms that

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PRINCIPLES ofIONIC ORGANIC REACTIONSBy ELLIOT R. ALEXANDER, University of Illinois. Presents the reaction mechanismsthat seem plausible for a number of the most important ionic organic reactionstogether with the chemical facts that support these ideas. This book sets down thefundamental processes from which a number of seemingly different organic reactionscan be constructed. It explains their scope and limitations and then illustratesthese principles by a number of common examples. Ready in May. Approx. 286pages. 212 illus. Prob. $4.50.

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Man's Physical UniverseTHIRD EDITION by ARTHUR T. BAWDENThis is the third edition of a highly successful text designed for survey courses in thephysical sciences. The emphasis throughout is on the scientific attitude and method.The new edition brings up to date the applications of general principles, now includ-ing the important advances of the past decade. To be published in the spring.

A Course in General ChemistryTHIRD EDITION, Semi-Micro Alternate Form by BRAY, LATIMER & POWELLWith semi-micro techniques now substituted for macro techniques, this well-knowntext presents a carefully planned sequence of experiments designed to give an under-standing of chemical equilibrium and the principles of qualitative analysis. The texthas been developed over a long period at the University of California for use in classescentered on the laboratory. To be published in the spring.

Fundamentals of Organic ChemistryREvISED EDITION of Conant 's Organic Chemistry by CONANT & BLATTA revision of an outstanding text in this field, this book is subtitled A Brief Coursefor Students Concerned with Biology, Medicine, Agriculture and Industry. Emphasisis placed on the biochemical and industrial aspects of organic chemistry. To be pub-lished in March.

Introduction to Semi-MicroQualitative Chemical Analysis

REVISED EDITION by Louis J. CURTMAN

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Schwarz fine chemicals satisfy the exactingrequirements of products intended for use inbiochemical or clinical research.

ALSO AVAILABLEAdenossne,adenosine-3-phos-phoric acid, adenosine-5-phosphoric acid,adenosine triphos-phate, cozymase,cytidylic acid,

desoxyribonucleicacid, glutathione,guanosine, guanylicacid, malononitrile.Complete informationon these and otherSchwarz chemicalson request.

LABORATORIES, INC.204 East 44th Street New York 17. N. Y.

CAMBRIDGEelectron - rayRESEARCHpH METER

RANGE AND ACCURACY: Sensitivity .005 pH; read-ings reproducible to .01 pH; accuracy .02 pH. Range 0to 14 pH; 0 to 1200 m.v. ELECTRON-RAY NULLINDICATOR: Replacing the usual galvanometer, theelectric eye provides quick and accurate null-point indi-cation without possible damage to a delicate galvanom-eter. NO BATTERY NUISANCE: All-electric; plugsinto any 110-volt AC Outlet. ELECTRODE SYSTEM:Sturdy glass electrode of condenser type is supplied.Micro condenser or dipping type glass electrodes canalso be furnished. COMPACT AND PORTABLE.Laboratory and Industrial Models also available. Sendfor bulletin No. 910 MA.

LINDEMANN ELECTROMETER21A 0 25M 1 E"

This instrument is extensivelyused for the determination ofradio-active emission. Has highsensitivity, good stability anddoes not require leveling. Sendfor descriptive literature.

CAMBRIDGE INSTRUMENT CO., INC.Pioneer Manufacturers of Precision Instruments

3748 Grand Central Terminal. New York 17, N. Y.

IGLASS ABSORPTION|CELL^S made KLETT

Makers of Complete Electrophoresus ApparatusSCIENTIFIC APPARATUS

Klett-Summerson Photoelectric Colorimeters-Colorimeters - Nephelometers- Fluorimeters-Bio-Cclorimeters-Comparators -Glass Stand-ards-Klett Reagents.

Klett Manufacturing Co.179 East 87 Street, New York, New York

THE YEAST CELLIts Genetics and Cytology

by Carl C. LindegrenChairman, Department of Microbiology

Southern Illinois UniversityCONTENTS: Important Yeasts and their LifeCycles . Cultivated Yeasts . Sporulation- StainingTechniques * Cytology * Storage of Reserves . In-duction of Dormancy and Conditions for Reactiva-tion * Techniques for Microdissection * Preserva-tions of Cultures . Hybridization . Genetical Char-acters * Comparison of Sexual Reproduction inYeasts and Other Microorganisms * Segregation,Variation and Recombination . Variation in Growthand Fermentative Capacity * Depletion Mutation -Back Mutation and Progressive Mutation * Devel-opment of Fertile Breeding Stocks . Regular Men-delian Inheritance * Irregular Ratios * Effect ofMedium on Apparent Vitamin Synthesizing De-ficiencies . Chromosome Maps . The Bearing of theData from Yeast Genetics on the Current Conceptof the Gene.

384 pages-Illustrated-Price $7.00

EDUCATIONAL PUBLISHERS, Inc.122 N. Seventh St. St. Louis, Mo.

Wegh4tA os7Weight 3% oz.

20 SCIENCE March 17, 1950, Vol. 111

Three ofThe SpecializedQuality Products

of Propper

made to PAPER-THIN proportionsPropper Select Quality Micro Cover Glasses are precisionmade by craftsmen of long experience in the exacting re-quirements of scientific glass manufacture. Only paper-thinglass which meets the rigid specifications authorized by themedical services of the U.S. Army, the U.S. Navy and theVeterans' Administration is used.

Propper Select Quality Cover Glasses are made of a superiornon-fogging, non-corrosive glass-extremely hard, low infree alkali, and free of bubbles, pits or striations. They are ex-pertly cut, gauged, weighed and packed in our own factory.

Propper Select Quality Glasses are guaranteed to be withinthe following specifications for thickness.

No.012

mm.less than .12.13 - .17.17 - .25

Inchesless than .0050.0050-.0066.0067-.0097

Cotton-cushioned in individual hinged boxes containing ½ oz.,they are available in a complete range of sizes in squares,circles and rectangles. Order from your regular supplier.

p1 NUFACTURIG COMPANY* INC

1Q-34 44TH DRIVE, LONG ISLAND CITY 1, N.Y.

r~ ~~--------a--~--___-__f ADAPT YOURMtCIO&CO0PE FOR PHASE

IAswithAcI~~ ~ ~ ~ ~ |...A _

I1.'1I

I:0SSPEN-CE.RqICROSC

.- -...'-4

M1O'

PRICE

ft is $1759A1for Cat. No.Condensphragmswtring tObjec

1000150 Phase Turret You can enjoy the superiority and ver-er, 4 annular dia- satility of AO Spencer Phase Accessoriesasselected,andcen- even if your microscope is not a Spencertelescope, in case. model. The new Universal Phase Turret:tives extra, as Condenser can be fitted to many makesselected. of microscopes.

This adaptation now extends to manymicroscopists the greater range and con-

venience ofAO Spencer Phase equipment in Bright, Dark, andB Minus contrast. Its worth has already been acclaimed byscientists here and in over 20 foreign countries. The TURRETDIAL ROTATES EASILY without danger of disturbing themicroscope. INTERCHANGEABLE ANNULAR DIA-PHRAGMS are brought into correct position without back-lash DIAPHRAGMS CAN BE PARCENTERED to four phaseobjectives, eliminating recentering when changing objectives.CENTERABLE MOUNT permits accurate location of phasecondenser in substage. LONG FOCUS ANNULAR DIA-PHRAGMS are available for micromanipulation and tissuecultures located up to 17mm above stage. A wide selection ofobjectives is avai able to suit individual needs.

See your AO Spencer Distributor or write Dep4,C3.

AT D

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