a a -

SCI ENCEJULY 8, 1949

AN INSTITUTE OF MICROBIOLOGYSELMAN A. WAKSMAN

INTERPRETATION OF ULTRAVIOLETABSORPTION BY

CELLULAR NUCLEIC ACIDSBARRY COMMONER

TECHNICAL PAPERSCOMMENTS & COMMUNICATIONS

IN MEMORIAMBOOK REVIEWS

NEWS AND NOTES

COMPLETE TABLE OF CONTENTS ON PAGE 3VOLUME 110, NUMBER 2845

_

AMERICAN ASSOCIATION FOR THE

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ADVANCEMENT OF SCIENCEUaU

t!5fkAc:rloNrloN PROBLEMS?here's help for you

HIS tireless servant in your laboratory will automaticallycollect any number (up to 200) of rigidly controlled samples

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All you have to do is to set it up for the conditions of thechosen experiment, short or long, and then leave it alone.The machine will plod along without attention hour after hour,all day (and night) long. When the job's done, it will shutitself off,

The Technicon Fraction Collector has been thoroughlytested in actual laboratory installations, where it has proveninvaluable to busy research staffs. We shall be happy to sendyou details.

Ref. Chromatography of Amino Acids on Starch Columns-W. H. Stein and S. Moore, Jrnl. Biol. Chem. 176, 337,(1948)

saves time and laborrelieves laboratory staff of the fretful and time..consuming chore of fraction-cutting: releases workersfor other duties.

' triples work outputyou can run it twenty-four hours a day, continuously,to triple fractionation output as compared with on 8hour laboratory day.

gives greater resolutionby collecting a large number of small fractions,rather than a few gross ones, you'll get more datafrom a given fractionation, e.g. a chromatogram, ora fractional distillation.

assures accuracybecause the possibility of human error is automati-cally ruled out. Now fraction-collection becomes astraightforward mechanical procedure.

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American Illustrated Medical Dictionary

For a half-century the American Illustrated Among these are:has been the dictionary of choice among an 1. Completeness. The Twenty-first Editionoverwhelming majority of scientists in the defines more than 130,000 words and terms.fields of medicine and biology. Their pref- 2. Up-to-dateness. The Amerncan Illus-erence is very clearly indicated by the fact trated Medical Dictionary has always madethat the Amrercan Illustrated is the required a feature of Dew words. More than 2000 ofdictionary in 85% of all medical schools in them were added for this edition.the United States in which ownership of a .Authry T hisd tionaditonr is.bl,,. 3. Authority. TIhis dictionary has enjoyedditoayisolgtry, the unquestioned confidence of American

This great popularit isnotacscientists for 50 years. Terminology con-by anyrmeansTheul Americannacciltrat forms to the standards of leading scientificby any means. The American Ilustratedz bodies.has achieved and maintained its eminenlt boishasachieved and maintained its eminent Edited by W. A. NZWMAN DoRLAND, M.D., Member of theposition because its editors are careful to Committee on Nomenclature and Classlication of Diseases,

tin those AmerIcan Medical Association. 1660 stare d~,*ing'preserve, through successive editions, those 880 illustrations, 100 In color. Plexigie or st bxi9ditg.features which scientists have commended. Plain, $8.00; thumb-indexed, $8.50. Twehty-kft Bdition.

B. SAUNDeRS COMPANYA Ad VWest Washington SquareWy B @ FRAURAX^@ vemran . Philadelphia 5

SCIENCE 1July 8, 194R Vol. 1 10

2 SCIENCE July 8, 1949, Vol. 110~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Just published

Pre-Medical Physical ChemistryBy Matsen, Myers and HackermanThis new book presents the principles of physical chemistry with particular ref-erence to those which have, or are expected to have, application to the study ofmedicine and other biological sciences. An extensive treatment of properties ofsurfaces and of colloidal systems has been included. Published June 10. $4.75.

The Supersensitivity of DenervatedStructuresEXPERIMENTAL BIOLOGY MONOGRAPHS By Cannon and Rosenblueth

This monograph is an examination of the data which lead to the inference thatdirectly or remotely denervated structures become sensitive to the excitatory aswell as to the inhibitory actions of sundry chemical substances and of impingingnerve impulses. Many physiological and clinical implications of the law are dis-cussed. Published in July. $6.00 (probable).

Ready this summer

College BotanyBy Hylander and StanleyThis new text for a year's course in general botany is built around four specificaims: to secure a proper balance in the amount of subject matter devoted to eachspecial field in botany; to suit the content and method of presentation to the needsof beginning students; to develop an awareness of the importance of plant lifeand intelligent use of plant resources; and to utilize visual instructional materialsto the fullest advantage. To be published this summer. $5.50 (probable).

Elementary Laboratory Experiments inOrganic Chemistry FOURTH EDITION By Adams & Johnson

In the fourth edition of this popular manual, the sections on laboratory operationshave been revised extensively so that greater emphasis is given to details of correctmanipulation and the exposition of underlying principles. Several new experi-ments have been added to provide a wider selection and permit further variationfrom one year to another. To be published in August. $3.25 (probable).

THE MACMILLAN COMPANY60 Fifth Avenue, New York 11, N. Y._

2 SCIENCE July 8, 1949, Vol. 110

SCIENCEVol. 110 No. 2845 Friday, July 8, 1949

An Institute of Microbiology-Its Aims and Purposes:

SelmanA.Waksman ................ ............. 27

On the Interpretation of theAbsorption of Ultraviolet Lightby Cellular Nucleic Acids:

BarryCommoner .............................

Technical PapersChromosome Numbers for Two Species ofMexican Commelinaceae:Earlene Atchison, H. E. Moore, Jr.,

andC.E.Wood, Jr. ............... .......................... 41The Application of the Beer-Lambert Law to

Optically Anisotropic Systems:Barry Commoner and David Lipkin .................. 41

Opalescence of Serum after Total BodyX-Irradiation as a PrognosticSign of Death:

Robert L.Rosenthal ........................................ 43An Automatic Analyzer for the Study of

Speech in Interaction and in FreeAssociation:Marcel Verzeano and Jacob E. Finesinger ...... 45

Increasing the Efficiency of the Laying Hen:H.D.Goodale . .........................................................

Low Temperature and Survival of EmbryonicTissue:

JohnFerguson . .............................................................

Comments and CommunicationsReplanting "Discarded" Varieties as a Means

of Disease Control; Age of Canada's Prin-cipal Gold-producing Belt; Some SimpleCalculations Concerning the Efficiency of the

Photosynthetic Mechanism .............................................

In MemoriamPaul Rode: E. Raymond Hall..... ...........William John Dann: Philip Handler .....................

Book ReviewsSurface active agents: their chemistry and

technology: Anthony M. Schwartz andJames W. Perry.Reviewed by James W. McBain ......................

Temperature and human life: C.-E. A. Winslowand L. P. Herrington.Reviewed by Clarence A. Mills .........

News and Notes.

Science, a weekly journal founded in 1880, is publishedeach Friday by the American Association for the Advance-ment of Science at the Business Press. 10 McGovern Ave..Lancaster, Pa. Editorial and Advertising Offices, 1515 Massa-chusetts Ave., N.W., Washington 5, D. C. Telephone. Execu-tive 6060. Cable address, SCIMAG, Washington. D. C.Entered as second-class matter at the Post Office at Lancaster.Pa., January 13, 1948, under the Act of March 3. 1879.Acceptance for mailing at the special rate postage providedfor in the Act of February 28, 1925, embodied in Paragraph 4,Sec. 538, P.L. and R., authorized January 13, 1948.

Manuscripts submitted for publication should be sent to theEditorial Office, with stamped, self-addressed envelope enclosedfor possible return. The AAAS assumes no responsibility forthe safety of the manuscripts or for the opinions expressedby contributors.Annual subscription, $7.50; single copies, $.25: foreign

postage, outside the Pan-American Union, $1.00: Canadian

postage, $.50. Remittances and orders for subscriptions andsingle copies should be sent to the Circulation Department,Science, 1515 Massachusetts Ave., N.W., Washington 5. D. C.Membership correspondence for the AAAS should be addressedto the Administrative Secretary at the same address.Change of address. Four weeks' notice Is required for

change of address. This should be sent to Science Recorder,1515 Massachusetts Ave., N.W.. Washington 5, D. C. Whenordering a change, it is necessary to furnish an address stencillabel from a recent issue. Claims for a missing number willnot be allowed if received more than 60 days from date ofissue. No claims allowed from subscribers due to failure tonotify the Circulation Department of a change of address orbecause an Issue is missing from their files, or for any reasonfrom subscribers in Central Europe, Asia, or the Pacific Islands(other than Hawaii).The AAAS also publishes The Scientific Monthly. Subscrip-

tion rates on request.

3

AAAS EDITORIAL BOARD(Terms expire July 31, 1949)

Arthur C. Bevan Edward U. CondonH. Bentley Glass

Malcolm H. Soule Everett S. WallisGeorge A. Baitsell

Editor-in-ChiefBeth Wilson

Executive Editor of Science

F. A. Moulton, Advertising Representative

CONTENT

46

47

49

5151

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a _%

4SCIENCE July 8, 1949, Vol. 110

Alconox is not a soap. It's a powerfuldetergent and wetting agent that actu-ally works its way under oil, grease,wax, etc., and literally floats the dirtaway. Excellent for cleaning Instru-ments, and other items made of glass,metal,.porcelain, etc. If your cleanserdoesn't offer all the advantages ofAlconox, why not give Alconox a triql?

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SCIENCE July 8, 1949, Vol. 110

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6 SCIENCE July 8, 1949, Vol. 110

July 8, 1949,VoL 110 SCIENCE 7~~~~~~~~~~~~

BARGAINS in WAR SURPLUS OPTICSASSEMBLE YOUR OWN BINOCULARS!Complete Optics Complete Mews! Parts

Save More Than 'A* Regular CostGOVT. 7 x 50 BINOCULARS

Here's an unusual opportunity tosecure a fine set of Binoculars at

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10 LENS KIT-THE LENS CRAPTERS DELIGHT!Kit includes illustrated booklet . . sspecific project for everylens in the kit. Use these lenses in photography for copying,ULTRA CLOSE-UP SHOTS, Micro-photography, Koda-chrome Viewer, etc. Dozens of other uses in experimentaloptics, building TELESCOPES, low power Microscopes, etc.Stock#2-W .100 Postpaid

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July 8, 1949, Vol. 1 10 SCIENCE 7

SCIENCE July 8, 1949, Vol. 110

You requested it and here it is! TheIndividual Annular Stop Long Work-

* ~~ing Distance Condenser ... for phasecontrast examination of tissue culturesin flasks or chambers. Provides a longworking distance... from 8m~m to

A '_;10mm in air. Designed for quick, easymounting on either Bausch & Lomb

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Optical Company, 642-I St. PaulStreet, Rochester 2, New York

8 SCIENCE July 8, 1949, Vol. 1 10