19 June 1959, Volume 129, Number 3364

AMERICAN ASSOCIATIONFOR THE

ADVANCEMENT OF SCIENCE

Board of Directors UnsePAUL E. KLOPSTEG, PresidentCHAUNCEY D. LEAKE, President Elect SeveWALLACE R. BRODE, Retiring President appropH. BENTLEY GLASS successGEORGE R. HARRISON technicMARGARET MEAD over tiTHOMAS PARKDON K. PRICE hersgofMINAREESa big eWILLIAM W. RUBEY wants

ALAN T. WATERMAN word l1PAUL A. SCHERER, Treasurer plant IDAEL WOLFLE, Executive Officer on the

_________ Menthat is,

DAEL WOLFLE, Executive Officer wouldGRAHAM DUSHANE, Editor

JOSEPH TURNER, Assistant Editor also haROBERT V. ORMES, Assistant Editor ganda

, ~~~~~~TheAEditorial Board and p

DONALD J. HUGHES H. BURR STEINBACH ina pKONRAD B. KRAUSKOPF WILLIAM L. STRAUS, JR. in a pEDWIN M. LERNER EDWARD L. TATUM aboutC

AnotEditorial Staff technic

JUNE G. BANDY, SARAH S. DEES, NANCY S. missileHAMILTON, WILLIAM HASKELL, OLIVER W. HEAT- issileiWOLE, YUKIE KOZAI, ELLEN E. MURPHY, BETH- is desifSABE PEDERSEN, MADELINE SCHNEIDER, NANCY L. or last-TEIMOURIAN, MARIA A. WOLSAK. craft, V

EARL J. SCHERAGO, Advertising Representative differinwith timoney

SCIENCE, which is now combined with THE recomnSCIENTIFIC MONTHLY, is published each Fri-day by the American Association for the Advance- unchanment of Science at Business Press, Lancaster, Pa. HowThe joint journal is published in the SCIENCE decid.nformat. Entered at the Lancaster, Pa., Post Officeas second class matter under the Act of 3 March to deci1879. SCIENCE is indexed in the Reader's Guide politic;to Periodical Literature.

Editorial and personnel-placement correspond- deed,ence should be addressed to SCIENCE, 1515 a repoMassachusetts Ave., NW, Washington 5, D.C. Senato:Manuscripts should be typed with double spacingand submitted in duplicate. The AAAS assumes no lobby."responsibility for the safety of manuscripts or for appropthe opinions expressed by contributors. For de- . .tailed suggestions on the preparation of manu-decsio:scripts, book reviews, and illustrations, see Science action125, 16 (4 Jan. 1957). questio

Display-advertising correspondence should be qaddressed to SCIENCE, Room 740, 11 West 42 weapolSt., New York 36, N.Y. WheChange of address notification should be sent to servers

1515 Massachusetts Ave., NW, Washington 5, D.C., basis. 14 weeks in advance. If possible, furnish an addressstencil label from a recent issue. Be sure to give port fuboth old and new addresses, including zone num- powerebers, if any.Annual subscriptions: $8.50; foreign postage, Adviso

$1.50; Canadian postage, 75g. Single copies, 35¢. to presCable address: Advancesci, Washington. the del

Energyunderpositior

SCIENCE

1ttling Side to Settling Technical IssuesUral recent disputes between Congress and the Administration overnriations for research and weapons pose again the question of howful our government is at bringing objective judgment to bear oncal issues. One dispute between Congress and the Administration ishe direction of the nuclear-powered aircraft program. Some mem-the Joint Committee on Atomic Energy want funds increased andifort made now to get a plane in the air, while the Administrationto limit the program to further research on the power plant. The'imited is perhaps not quite right, for, although apparently no powerhas yet been demonstrated, almost a billion dollars has been spentproject in the past 13 years.nbers of the Congressional committee have argued for early flight,flight in the next four or five years, on the grounds that this effortanswer technical questions that the designers of later models wouldave to face. And committee members have emphasized the propa-value of having a nuclear-powered aircraft before the Soviets do.Ldministration's position is that to begin construction of a fuselage)wer plant before further research on the power plant would resultlane of such poor performance that it would be nothing to boastand would be of no military use.ther dispute between Congress and the Administration involvingcal matters is over the relative merits of the Air Force's Bomarcthe Army's Nike-Hercules, and the Army's Nike-Zeus. The Bomarc

gned for area defense, while the Nike-Hercules is designed for point,,ditch, defense. Both weapons are for use only against piloted air-while the Nike-Zeus is for defense against ballistic missiles. Besidesag in use, the weapons also differ in their state of development,he Nike-Hercules the most proven weapon. In sending the defensebill to the Senate, the House cut drastically the Administration'snendation for the Bomarc program, left the Nike-Hercules programiged, and added substantially to the Nike-Zeus program.v do Congress and the Administration compare in their efforts atig technical issues? Many observers find that when Congress attempts:ide technical matters, it is more likely to do so on the basis ofal and financial factors than on scientific or military ones. In-President Eisenhower made this point recently when replying toarter's question concerning his having spoken sharply to severalwrs about what the President was quoted as calling a "munitions' Of course, Congress can fill important functions. By challenging'riations, for example, it can force the Administration to makeens that the Administration has so far failed to make. Congressionalon the various missile programs resulted in the Pentagon's decidingns of air defense, including such matters as the proper mix of thens, in its efforts to push its program in the Senate.n the Administration does decide technical matters, so many ob-find, it does have a good chance of deciding them on an objective[he Administration's decision in this year's budget message to sup-Lrther research on the power plant before attempting to fly a nuclear-.d aircraft is based in part on the judgment of the President's Sciencetry Committee. However, the Administration can also be subjectedssure from political groups, the armed services, and companies infense business. At the insistence of the Joint Committee on Atomicr, the nuclear-powered aircraft program has again been broughtreview. It will be instructive to see whether the Administration'sn changes, and, if so, what its reasons are.-J.T.

BAUSCH & LOMBTEREOMICROSCOPES

FEATURING

STEREO

CONTIINUOUSLYVARIABLE POWER

Here's a completely new optical concept to speedand simplify work requiring 3D views. Just turnthe magnification knob and watch the crisp stereoimage zoom to the exact size you need. Not justa few fixed powers, but any power within the widestereo range. The newest step forward to faster,easier 3D work ... exclusive with Bausch & Lomb.

Featuring Exclusive POWER POD Design Concept* Sealed to prevent dust and foreign matter

from entering optical system!* No nosepiece!* No individual objectives ...

no objectives to change!* No image jump!* No image blackout!

BAUSCH & LOMB OPTICAL CO.A42 St. Paul Street, Rochester 2, N. Y.

l D Send me new B&L Stereomicroscope Catalog D- 15.

D Schedule a demonstration at my convenience.

Name, Title .......................................................................Company.--------------------------------------Addressn .............................................................................

I Address............................................. ............. ............

1 City.Zone.State.

1642

Featuring NEW LOW PRICE. . . about one-third lower than previous line!

A S

| America's only complete optical source| ... from glass to finished product

MAIL COUPON NOW!

SCIENCE, VOL. 129

I

MeetingsSociety in the Ancient Near East

On 4-7 Dec. 1958, a symposium washeld in the Oriental Institute of the Uni-versity of Chicago, on "The Expansionof Society in the Ancient Near East andits Cultural Implications." There weresome 70 invited participants, of whom20 represented other institutions in thiscountry and institutions abroad. Abouthalf of the group were scholars whosecompetence lay in the natural and socialsciences and in the culture-historical se-quences of areas other than those of theancient Near East. The remainder of the

Identification of Micron and SubmicronParticles.Techniques are described for identification andsize estimation of water or acid-soluble atmos-pheric particles. After collection, MF filter isplaced on appropriate reagent solution (from 3to 20 minutes). Filters are then washed, dried,mounted and microscopically examined (darkfield) for characteristic reaction "spots." Reagentsand spot characteristics are given.

Lodge, i. P., Jr., Tufts, B. J.Tellus

VII, 1956, 2

Methods for the Evaluation of Pasteuri-zation.Two methods, one enzymatic and one microbio-logical, are described to test beer for adequacyof the pasteurization received. The second methoduses an HA Millipore filter to retain all organismsfrom a beer sample. Yeast colonies will developon the MF in 36 to 48 hours on hopped wort at230C. Lactobacilli and pediococci develop on theMF in 6 to 14 days on hopped wort agar in C02atmosphere at 230C.

Hoas, G. J., Fleischmon, A. i.Wallerstein Laboratory Communications

XX:68. March. 7957

aU

Attach Thisto Your Letterhead

Send catalog, price list and tech-nical bibliography. My principalfields of interest are: .........

sign your name and mail to

MilliporeFILTER CORPORATION

Dept. S, Bedford, Massocimuwetts

1680

group consisted of specialists in the ar-cheology, philology, and culture-historyof the eastern end of the Mediterraneanin pre-Greek, Greco-Roman, and Is-lamic times.The symposium included a series of

general background papers prepared byRobert M. Adams, Robert J. Braidwood,Mircea Eliade, I. J. Gelb, David Grene,G. E. von Grunebaum, Clyde Kluck-hohn, Karl Polanyi, Max Rheinstein,Otto von Simson, and Milton Singer, re-spectively. There were introductory andconcluding addresses by Lewis Mum-ford. The six sessions dealt with thebackground for the expansion of societyin thy alluvium and the upland of theNear East, with the development of cul-

Use of Membrane Filters in the Measure-ment of Biological Incorporation ofRadioactive Isotopes.A technique is presented for accurately estimat-ing by direct radiation counting the total isotopeincorporation into metabolizing cells. After ex-posure to the labeled substrate (C 1402) the cellsare killed, transferred to 10-20 ml. H20, andfiltered through a 1" HA Millipore filter. Afterflushing and drying, the MF is introduced into agas-flow chamber for direct counting of B radia-tion from the dry cells.

0 Atkinson, D. E., McFadden, B. A.Journal Bacteriology, 7 1:1:123-24, 1956

Critical Comparison of Collection Efficien-cies of Commonly Used Aerosol SamplingDevices.The extent to which the theory of collection tech-niques could be applied to commonly-used fieldinstruments has been determined. Instruments in-cluded sedimentation chambers, MSA electricprecipitator, Greenberg-Smith impinger, MilliporeFilters, Cassella thermal precipitator and an im-pactor. Collection efficiencies for MF's weregreater than 99% for all aerosols. Glycerol aero-sols were collected at greater than 99.995%with the MF the limit of measurement.

Schodt, C., Codle, R. D.Analytical Chemistry, 29:6:864-68, June, 1957

ABSOLUTE SURFACE RETENTION OFALL PARTICLES LARGER THAN PORE SIZEParticles screened from liquids or gases liedirectly on the surface of the Millipore filter

iita single plane where they may bereadily examined or tested. Fluids cleanedwith l100% cut-off at specific pore size.* SQ million capillary pores of precise size per sq.

cm. of surface area.* Absolute surface retention of all particles larger

than pore size.* Pores are 80% of total filter volume, permitting

high flow rates.* Heat and chemical resistance characteristics typical

of esters of cellulose.* Filter becomes completely transparent for micros-

copy. by applying immersion oil.* Ten porosity grades from 0.01 to 5.0 p.

ture in the national states, and with thedevelopment of cultures in the great em-pires. Discussion leaders included R. M.Adams, N. Glueck, I. P. H. Jacobsen, B.Landsberger, J. A. Wilson, H. Guter-bock, and C. H. Kraeling.

It has been traditional for scholarsconcerned with the ancient Near Eastto restrict their studies to their own areaof competence. The success of the sym-posium rested in fair part on the factthat these traditional scholarly concernswere communicated to and drew fruit-ful discussion from interested colleaguesin the natural and social sciences andfrom culture historians concerned withother areas of the Old and New Worlds.As the symposium progressed, the ex-pansion of society and the appearanceand development of urban civilization inthe ancient Near East came to be seenagainst a broad background of generalphenomena in both natural and culturalhistory.

Given the present order of incomplete-ness of knowledge, it was natural thatthere were more new problems raisedthan old problems solved. The impor-tance of the symposium rests in itssuccess as a means of bringing aboutcross-disciplinary communication. Theproceedings of the symposium will bepublished by the Oriental Institute assoon as practicable.

CARi. H. KRAELINGOriental Institute,Unirersity of Chicago, Chicago, Illinoi..

Pan American Medical -Congress toInclude Space-Medicine Section

The next congress of the Pan Ameri-can Medical Association, 745 Fifth Ave..New York 22, N.Y., is to be held inMexico City, from 2 May to 11 May1960. Some 5000 physicians from the 22American nations are expected -to at-tend. The scientific program of the con-gress, th ugh its 48 different medicalsections, will include all branches ofmedicine and surgery; also a section ondentistry. The congress will also havescientific and commercial exhibits, pan-els on special subjects, medical motionpictures, and closed-circuit televisiondemonstrations of surgical and dentaltechniques. There will be some new sec-tions, such as a section on hematology.a section on general medical practice.and-of special interest-a section onspace medicine.Major General Otis 0. Benson, Jr.,

commandant of the School of AviationMedicine, Randolph Air Force Base.Tex., has been named president of thespace-medicine section, and S. Fred.Singer, professor of physics at the Uni-versity of Maryland, is secretary. TheLatin American chairman of the sec-tion is Col. Rail] Terres y Prieto, M.C..

SCIENCE. VOL. 129

1111111111111111111111111111A.. ..., 1 0, -1

REICHE7

1 INSTRUMENTS FOR...

m

ft:

"FLUOREX"unit with REICHERT"BIOZET" Microscopeand Photo-Micrographic

Accessories.

The "FLUOREX" unit may also be used withmicroscopes of other makes.

For unlimited versatility with two lightsources and instantaneous transition toFluorescent Microscopy.

For full details and specifications write or phone . . .

WILLIAM J. HACKER & CO., INC.P.O. BOX 646

WEST CALDWELL, N.J.

CApitol 6-8450

19 JUNE 1959

NEW Revisions fromMcGRAW-HILLPRINCIPLES OF BIOCHEMISTRY

Second EditionAbraham White, Ph.D.; Philip Handler, Ph.D.;

Emil L. Smith, Ph.D.;DeWitt Stetten, Jr., M.D., Ph.D.

This new second edition is an exceptionally mod-ern, well-balanced presentation, emphasizing thefundamental principles and concepts of biochem-istry. Particular consideration is accorded to themechanisms of, and factors influencing, the bio-logical reactions where they are known. As a resultof important new advances in the, field of metabo-lism and endocrinology, these chapters have beencompletely rewritten in line with the rapid ad-vances in these fields. The material on cell struc-ture, formerly in the opening chapter, has beenexpanded into a fuller treatment of biochemicalarchitecture of the liver.

1048 pp., 6 x 9, illus., $15.00

ANALYTICAL CYTOLOGYSecond Edition

Edited by Robert C. Mellors, M.D., Ph.D.This volume is designed to serve as a reference bookfor research workers, professors, graduate and ad-vanced undergraduate students in the biologicaland medical sciences. A new chapter has beenadded on the technique and application of thefluorescent antibody method, one of the majoradvances in microscopic methodology. A new chap-ter has also been added dealing with the intra-cellular localization of chemical constituents pre-senting the integrative synthesis of biomorphologyand biochemistry-a major achievement of ana-lytical cytology.

518 pp., 6 x 9, illus., $17.50

The Blakiston Division3 3 0 W. 42nd Street

McGraw-Hill Book Co., Inc.New York 36, N.Y.

You may send me on approval:White et al: PRINCIPLES OF BIOCHEMISTRY ...... $15.00

o Mellors: ANALYTICAL CYTOLOGY ....... ........... $17.50

NAME .........................................................

ADDRESS .....................................................

CITY.. ZONE ... STATE .... S. 6/59

1681

.1 5W

TO ANALYTICAL CHEMISTSIf you are an analytical chemist,this handy, desk-size S&S Filtra-tion Chart belongs in yourlaboratory.Analytical laboratories have longbeen familiar with standardized,high-quality S&S AnalyticalFilter Papers.Now, here is complete data onthe relative retention values ofS&S Analytical Filter Papers, andother brands, in convenient sizefor ready reference. This datamakes it possible to tell at aglance which grade of paper toselect for a given analysis.Send for your valuable, free S&SFiltration Chart. Act now! Usethe handy coupon below!S&S ULTRA FILTERS

S&S dual-purpose ultra filters-smooth-surfaced membranes pos-sessing extremely uniform micro-structure-are ideal for filtration ofcolloids, proteins, and micro-organ-isms, as well as dialysis and osmosis.Mail coupon below for your freeS&S Ultra Filter Catalog.

MAIL THIS COUPON TODAY

CARL SCHLEICHER & SCHUELL CO.Keen., New Hampshire, Dept. S-69Send me your FREE

O S&S Filtration Chart| S&S Ultra Filter CatalogNam&

CompanyAddresscity Sta I

surgeon general of the Mexican AirForce, while Brig. Gen. Donald D.Flickinger, staff surgeon and director oflife sciences, Air Research and Develop-ment Command, is North Americanchairman.

Semiconductor Surfaces

A conference on semiconductor sur-faces will be held at the U.S. NavalOrdnance Laboratory, White Oak, SilverSpring, Md., 3-4 December, under thesponsorship of NOL and the Office ofNaval Research. Papers are invited onthe following subjects: clean germaniumand silicon surfaces, etched and chemi-cally treated germanium and silicon sur-faces, theory of surface properties, sur-face chemistry, and new experimentalapproaches. The proceedings will bepublished. Those interested in attendingthe conference or in submitting papersmay write for information to the chair-man of the steering committee, Dr. J. N.Zemel, U.S. Naval Ordnance Labora-tory, White Oak, Silver Spring, Md.

Summer Biological Symposium

"Cell Structure and Function" will bethe theme of the tenth annual Biologi-cal Symposium, to be held 6-8 July atthe University of Michigan under theauspices of the division of biological sci-ences. Five prominent scientists fromthis country and abroad have been in-vited to discuss their recent work in thisfield. They are S. Granick and GeorgeE. Palade of the Rockefeller Institutefor Medical Research; H. E. Huxley ofthe department of biophysics, UniversityCollege, London; Hans Ris of the De-partment of zoology, University of Wis-consin; and C. F. Robinow of the Fac-ulty of Medicine, University of WesternOntario. For information about housingand other details, communicate with Dr.John M. Allen of the Department ofZoology, University of Michigan, AnnArbor, Mich.

Forthcoming Events

July

19-24. American Crystallographic As-soc., Ithaca, N.Y. (J. Waser, Rice Inst.,Houston 5, Tex.)

19-25. Pediatrics, 9th intern. cong.,Montreal, Canada. (R. L. Denton, P.O.Box 215, Westmount, Montreal 6.)

20-26. Radiation and AtmosphericOzone, joint symp., by Intern. Union ofGeodesy and Geophysics and World Mete-orological Organization, Oxford, England.(WMO, Campagne Rigot, 1, avenue dela Paix, Geneva, Switzerland.)

22-23. Rocky Mountain Cancer Conf.,Denver, Colo. (N. Paul Isbell, 835 Re-public Bldg., Denver 2.)

23-30. Radiology, 9th intern. cong.,Munich, Germany. (Sekretariat des 9 In-ternationalen Kongresses fur Radiologie,Reitmorstrasse 29, Munich 22.)

26-30. International PsychoanalyticalAssoc., Copenhagen, Denmark. (Miss P.King, 37 Albion St., London, W.2,

27-4. International Federation ofTranslators, Bad Godesberg, Germany.(Dritter Internationaler FIT-Kongress,Kongress Sekretariat, Bundesverband derDolmetscher und tCbersetzer e. V. (BDU)Hausdorfstrasse 2, Bonn, Germany.)

30-31. Computers and Data Processing,6th annual symp., Estes Park, Colo. (W.H. Eichelberger, Denver Research Inst.,Univ. of Denver, Denver 10, Colo.)

August1-8. World Congress of Esperantists,

44th, Warsaw, Poland. (Office of Intern.Conferences, Dept. of State, Washington25.)

4-5. American Astronautical Soc., 2ndannual western, Los Angeles, Calif. (A. P.Mayernik, AAS, 6708 53 Rd., Maspeth78, N.Y.)

6-8. Human Pituitary Hormones, col-loquium (by invitation only), BuenosAires, Argentina. (G. E. W. Wolsten-holme, Ciba Foundation, 41 PortlandPlace, London W.2, England.)

9-12. American Soc. of MechanicalEngineers (Heat Transfer Div.), conf.,Storrs, Conn. (D. B. MacDougall, ASME,29 West 39 St., New York 18.)

9-15. Physiological Sciences, 21st in-tern. cong., Buenos Aires, Argentina. (C.F. Schmidt, Univ. of Pennsylvania Schoolof Medicine, Philadelphia 4.)

10-13. National Medical Assoc., De-troit, Mich. (J. T. Givens, 1108 ChurchSt., Norfolk, Va.)

10-13. Society of Automotive Engineers,natl. West Coast meeting, Vancouver,B.C., Canada. (R. W. Crory, MeetingsOperation Dept., SAE, 485 LexingtonAve., New York 17.)

16-19. Botanical Nomenclature, discus-sions (Intern. Bureau for Plant Taxon-omy and Nomenclature), Montreal, Can-ada. (J. Rousseau, Natl. Museum, Ottawa,Canada.)

16-21. American Pharmaceutical As-soc., Cincinnati, Ohio. (R. P. Fischelis,APA, 2215 Constitution Ave., NW, Wash-ington 7.)

17. Ultrasonics, natl. symp., San Fran-cisco, Calif. (L. G. Cumming, Inst. ofRadio Engineers, 1 E. 79 St., New York21.)

17-21. Pacific Southwest Assoc. ofChemistry Teachers, Pacific Grove, Calif.(W. A. Craig, 416 N. Citrus Ave., LosAngeles 36, Calif.)

17-22. Logopedics and Phoniatrics,11th intern. cong., London, England.(Miss P. Carter, 46 Canonbury Square,London N.1, England.)

19-26. Refrigeration, 10th intern. cong.,Copenhagen, Denmark. (M. Kondrup,Danish Natl. Committee, Intern. Congressof Refrigeration, P.O. Box 57, Roskilde,Denmark.)

19-29. Botanical Cong., 9th intern.,Montreal, Canada. (C. Frankton, Secre-tary-General, 9th Intern. Botanical Cong.,Science Service Bldg., Ottawa, Ontario,Canada.)

SCIENCE, VOL. 129- m m - m_ A1682

19-29. International Assoc. of WoodAnatomists, Montreal, Canada. (IAWA,Laboratorium fur Holzforschung E.T.H.Universitatstrasse 2, Zurich, Switzerland.)

19-29. Mycological Soc. of America,Montreal, Canada. (E. S. Beneke, Dept.of Botany and Plant Pathology, MichiganState Univ., E. Lansing.)

19-29. Phycological Soc. of America,Montreal, Canada. (W. A. Daily, Dept. ofBotany, Butler Univ., Indianapolis 7,Ind.)

20-22. Rocky Mountain RadiologicalSoc., Denver, Colo. (J. H. Freed, 4200E. Ninth Ave., Denver 20.)

20-25. Chemical Thermodynamics,symp., Wattens, Austria. (F. VorlInder,Deutsche Bunsen-Gesellschaft, Carl-Bosh-Haus, Varrentrappstrasse, 40-42, Frank-fort a.M., Germany.)

20-27. Therapeutics, symp., Gardone,Italy. (R. Morf, c/o Sandoz S.A., Basel13, Switzerland.)

20-2. Limnological Cong., 14th intern.,Vienna and Salzburg, Austria. (Secretary,14th Intern. Limnological Congress, Bio-logische Station, Lunz am See, Austria.)

23-26. American Farm Economic As-soc., Ithaca, N.Y. (C. D. Kearl, Dept. ofAgricultural Economics, Warren Hall,Cornell Univ., Ithaca.)

23-27. Veterinary Medicine, 3rd Pan-American Cong., Kansas City, Mo. (B. D.Blood, Pan-American Congresses of Vet-erinary Medicine, P.O. Box 99, Azuk,Buenos Aires Province, Argentina.)

24-26. American Accounting Assoc.,Boulder, Colo. (C. Cox, 437 Hagerty Hall,Ohio State Univ., Columbus 10.)

24-26. Anti-Submarine Warfare (clas-sified), symp., San Diego, Calif. (R. R.Dexter, Inst. of the Aeronautical Sciences,2 E. 64 St., New York 21.)

24-26. Dynamics of Conducting Fluids,(American Rocket Soc., and Northwest-ern Univ.), Evanston, Ill. (J. J. Harford,ARS, 500 Fifth Ave., New York 36.)

24-27. American Hospital Assoc., NewYork, N.Y. (E. L. Crosby, 18 E. DivisionSt., Chicago, Ill.)

24-28. Australian and New ZealandAssoc. for the Advancement of Science,34th cong., Perth, Western Australia. (J.R. A. McMillan, Science House, 157Gloucester St., Sydney, Australia.)24-29. Infrared Spectroscopy Inst., 10th

annual, Nashville, Tenn. (N. Fuson, Di-rector, Infrared Spectroscopy, Fisk Univ.,Nashville 8.)

24-29. International Assoc. for Hydrau-lic Research, cong., Montreal, Canada.(IAHR, c/o Laboratoire Hydraulique,Raam 61, Delft, Netherlands.)

24-29. Ionization Phenomena in Gases,4th intern. conf., Upsala, Sweden. (A.Nilsson, Secretary-General, Inst. of Phys-ics, Upsala, Sweden.)

24-29. Polarography, 2nd intern. cong.,Cambridge, England. (Mrs. B. Lamb,Chemistry Lab., Evershed & Vignoles,Corner of Iveagh Ave., N. Circular Rd.,London N.W. 10, England.)

24-30. Modern Systems for Detectingand Evaluating Optical Radiation (In-tern. Optical Commission), symp., Stock-holm, Sweden. (S. S. Ballard, Dept. ofPhysics, Univ. of Florida, Gainesville.)25-27. Petroleum Industry Conf., AIEE,

Long Beach, Calif. (N. S. Hibshman,AIEE, 33 W. 39 St., New York 18.)19 JUNE 1959

"A simple method is the practical path to precision"

This is the

mnost practicodp11 meter

COMPAX is so simple, so extremely easy to use,that you'll wonder why all- pH meters aren't madethis way.

The ingenious COMPAX design employsultra-modern components to save space, main-tenance and your operating time. You use one con-trol, read from a dial, work with handy ColemanElectrodes. Precision is 0.02 pH.

Make no mistake . . . this is not a short-cutportable. COMPAX'S high efficiency and low cost(only $200.00) are the result of modern engineer-ing for mass production.

Skeptical? .. . Try it before you buy it!Clip this coupon to your letterhead and mail tous for a free trial. No strings attached.

CO LEMAN

Coleman Instruments Inc., Dept. S, Maywood, IllinoisLI Send me a Compax for a 10-day free trial.L I would like more information on the Compax.

NameCompanyAddressCity Zone State

1683

25-28. Alaskan Science Conf., AlaskanDiv., AAAS, 10th, Juneau. (N. J. Wili-movsky, Bur. of Commercial Fisheries, Box2021, Juneau.)25-28. American Dietetic Assoc., 42nd

annual, Los Angeles, Calif. (Miss R. M.Yakel, ADA, 620 N. Michigan Ave., Chi-cago 1 1, Ill.)

25-30. American Ornithologists' Union,Regina, Saskatchewan, Canada. (H. G.Deignan, Div. of Birds, U.S. NationalMuseum, Washington 25.)

26-29. International Assoc. of Milkand Food Sanitarians, Glenwood Springs,Colo. (V. T. Foley, Health Dept., KansasCity, Mo.)

26-29. International Union of Pure andApplied Chemistry, 20th conf., Munich,Germany. (Div. of Chemistry and Chemi-cal Technology, Natl. Research Council,Washington 25.)

27-29. American Assoc. of ClinicalChemists, 11th annual, Cleveland, Ohio.(A. Hainline, Jr., AACC, Cleveland ClinicFoundation, 2020 E. 93 St., Cleveland 6.)

27-29. American Physical Soc., Hawaii.(K. K. Darrow, APS, Columbia Univ.,New York 27.)

28-29. Weather Modification (withAmerican Soc. of Civil Engineers), conf.,Denver, Colo. (H. G. Houghton, AMS,Dept. of Meteorology, Massachusetts Inst.of Technology, Cambridge 39, Mass.)

28-30. American Folklore Soc., annual,Albany and Cooperstown, N.Y. (MacE.Leach, 110 Bennett Hall, Univ. of Penn-sylvania, Philadelphia 4.)

28-31. Astronomical League, Denver,Colo. (R. Dakin, 720 Victor Rd., Pitts-ford, N.Y.)

28-4. International Union for ScientificStudy of Population, cong., Vienna, Aus-

disposable plastic Peiri Dishesat ecouo#qy prices!

Lab-Tek quality. . .unmatched for quality construction.

. . .guaranteed the finest in service and accuracy.

... Lab-Tek disposable plastic petri dishescost less than five cents each in quantity orders.

See your Lab-Tek dealer. He can assure prompt deliv-ery of these outstanding new dishes. Stocked and dis.tributed by: Fisher Scientific Co.; Braun-Knecht-Hei-mann-Co.; Braun Chemical Co.; Scientific Supplies Co.

LAB-TEK PLASTICS CO.

39 E. Burlington Westmont, Ill. Phone: WO 9-2529.PSC

tria. (F. Lorimer, Dept. of Sociology,American Univ., Washington, D.C.)

30-3. American Inst. of Biological Sci-ences, annual, University Park, Pa. (H. T.Cox, AIBS, 2000 P St., NW, Washington6.)

The following 17 meetings are beingheld in conjunction with the AIBS meet-ing at University Park, Pa.American Microscopical Soc. (T. H.

Cheng, Dept. of Zoology and Entomology,Pennsylvania State Univ., UniversityPark.)American Phytopathological Soc. (J. E.

Livingston, Dept. of Botany and PlantPathology, Pennsylvania State Univ., Uni-versity Park.)American Soc. for Horticultural Sci-

ence. (R. E. Larson, Dept. of Horticul-ture, Pennsylvania State Univ., UniversityPark.)American Soc. of Human Genetics. (C.

C. Li, Graduate School of Public Health,Univ. of Pittsburgh, Pa.)American Soc. of Limnology and Ocean-

ography. (E. L. Cooper, Dept. of Zool-ogy, Pennsylvania State Univ., UniversityPark.)American Soc. of Parasitologists. (T.

H. Cheng, Dept. of Zoology and Ento-mology, Pennsylvania State Univ., Uni-versity Park.)American Soc. of Plant Physiologists.

(A. A. Benson, Agriculture and BiologicalChemistry, Pennsylvania State Univ., Uni-versity Park.)American Soc. of Zoologists. (A. An-

thony, Dept. of Zoology, PennsylvaniaState Univ., University Park.)

Biometric Soc. (ENAR). (Miss C. S.Weil, Mellon Inst., 4400 Fifth Ave., Pitts-burgh, Pa.)

Ecological Soc. of America. (M. W.Schein, Dept. of Poultry Husbandry,Pennsylvania State Univ., UniversityPark.)

Genetics Soc. of America. (.j. E.Wright, Dept. of Genetics, PennsylvaniaState Univ., University Park.)

National Assoc. of Biology Teachers.(H. S. Fowler. Science Education, Penn-sylvania State Univ., University Park.)

Nature Conservancy. (W. Sharp, Penn-sylvania Cooperative Wildlife Reserve,206 Forestry Bldg., Pennsylvania StateUniv., University Park.)

Society for Industrial Microbiology.(Miss M. B. O'Hara, Applied SciencesLabs., Inc., State College, Pa.; or A.Rose, 525 S. Gill St., State College.)

Society of Protozoologists. (H. Frings,Dept. of Zoology, Pennsylvania StateUniv., University Park.)

Society for the Study of Developmentand Growth. (J. E. Livingston, Dept. ofBotany and Plant Pathology, Pennsylva-nia State University, University Park.)Tomato Genetics Cooperative. (B. L.

Pollack, Dept. of Horticulture, Pennsyl-vania State Univ., University Park.)

30-4. American Cong. of PhysicalMedicine and Rehabilitation, Minneapo-lis, Minn. (Miss D. C. Augustin, 30 N.Michigan Ave., Chicago 2, Ill.)

30-4. Laurentian Hormone Conf.,Mont Tremblant, Quebec, Canada. (G.Pincus, 222 Maple Ave., Shrewsbury,Mass.)

SCIENCE, VOL. 1291684

for Partition Chromatographyand Paper Electrophoresis

The purpose of the pump is to produce artificialbreathing. A mechanically operated valve is

synchronized with the stroke. When the pump hasreached its maximum on the pressure side, the valve

disconnects the flow of air to the lungs and exhalationtakes place naturally. The mechanical valve through

which air is pumped is so made that oxygen or gas

mixtures may be added. A special feature of thisunusual pump is that the piston is always driven to the

top of its chamber; as a result no air is left in the

chamber at the end of a stroke. The volume can be

adjusted from maximum to minimum while the pumpis in operation. The bar over which the adjusting pinion

travels has been conveniently graduated. Thus thevolume may be varied from zero to 500 cc per stroke.

No. 70-879-Nine, ten, eleven and twelve inch driv-ing pulleys are supplied. A size A V-belt will fit thesepulleys. Overall dimensions, 14" wide, 29" long, 23"high.

Price without motor and Variable Drive $475.00 each

No. 70-8791-Same as No. 70-879 except with amotor including a drive which gives infinitely variablespeeds, ranging from 0-45 per minute.

Price of pump complete with motor and Variable Drive$745.00 each.

[MUUPPs L LDo 0Manufacturers & Distributors of Scientific Equipment

7f~j7 6th & Byrd Streets - Richmond, Ve.

19 JUNE 1959

GLASS ABSORPTIONmade Ikrky~by

SCIENTIFIC APPARATUSKlett-Summerson Photoelectric Colorimeters-Colorimeters - Nephelometers - Fluarimeters-Bio-Colorimeters - Comparators - Glass Stand-ards-Rlett Reagents.

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

U

a AL AL - a E

1685

KRYPTON-85 and CARBON-14, SULFUR-35 andTRITIUM Compounds in gas form.,For use in tracerstudies, leak detection, oil well repressurization studies andcounter standardization. The Matheson Company, Inc..Is now licensed by the A. E. C. to supply these radioactivegases. We Invite your Inquiries on using radioactive gasesfor your special requirements. Write to our SalesEngineering Department, P.O0. Box 85, East Rutherford,N.J. Our 1958-59 Gas Catalog Is now available on request.

Listing 80 compressed gases, gas mixing services and afull line of regulators, valves, flowmeters and accessories.

Compressed Gases and Regulators U East Rutherford, N. J.; Joliet, Ill.; Newark, Calif.

This valuable 38-page bookis yours for the asking!

With artifidcl satellites already launched and spacetravel almost a reality, astronomy has become today'sfastest growing hobby. Exploring the skies with a tele-scope is a relaxing diversion for father and son alike.UNITRON's handbook contains full-page illustratedarticles on astronomy, observing, telescopes and acces-sories. It is of interest to both beginners and advancedamateurs.

Consents include-* Observing thetosn,mm, planets andwoaders of tho sky

* Constellatiosn mapHints for obnerers~Glossary of telsope termsNeHw to choose aW ~Amateur cueb and no_pa

___;eI Plae rush to me, free o Arp, UNITRON's an Observer's

Gidoad Telesope Calolt43RNa I

c 686 ___ __t _ J

1686

Three symposium volumes frommeetings of the American Associa-tion for the Advancement ofScience-of importance to psychia-trists, neurologists, clinical psy-chologists, physiologists, pharma-cologists, and biochemists-and ofgreat interest to the general public.

Tranquilizing Drugs6" x 9", 205 pp., 32 ilius., refer-ences, index, cloth, March 1957.Price $5.00. AAAS Members' cashorder price $4.50.

Psychopharmacology6" x 9", 175 pp., bibliographies,index, cloth, 1956. Price $3.50.AAAS Members' cash order price$3.00.

Alcoholism-Basic Aspects and Treatment

6' x 9", 220 pp., 33 illus., refer-ences, index, cloth, May 1957.Price $5.75. AAAS Members'cash order price $5.00.

AAAS Publications1515 Moss. Ave., NW, Washington 5, D.C.

30-4. Medical Education, 2nd worldconf., Chicago, Ill. (World MedicalAssoc., 10 Columbus Circle, New York19.)30-5. World Federation for Mental

Health, 12th annual, Barcelona, Spain.(Miss E. M. Thornton, Secretary-Gen-eral, WFMH, 19, Manchester St., Lon-don W.1, England.)

30-6. History of Science, 9th intern.cong., Barcelona and Madrid, Spain. (J.Vernet, via Layetona 141, Barcelona.)

30-6. Residues on Crops and/or theProblem of Insect Resistance to Insecti-cides, symp., Munich, Germany. (R.Morf, Secretary-General, IUPAC, c/oSandoz S. A., Basel, Switzerland.)

30-6. Thermodynamics and Experi-mental Thermochemistry, 17th intern.cong. (Intern. Union of Pure and Ap-plied Chemistry), Munich, Germany.(Div. of Chemistry and Chemical Tech-nology, Natl. Research Council, Wash-ington 25.)

31-2. Stratospheric Meteorology, conf.,Minneapolis, Minn. (H. G. Houghton,AMS, Dept. of Meteorology, Massachu-setts Inst. of Technology, Cambridge 39,Mass.)

30-12. International OceanographicCong. (AAAS, UNESCO, ICSU), NewYork, N.Y. (Miss M. Sears, chairman,Woods Hole Oceanographic Institution,Woods Hole, Mass.)

31-2. Free Radical Stabilization, 4thintern. symp., Washington, D.C. (A. M.Bass, Natl. Bureau of Standards, Wash-ington 25.)

31-3. Biological Photographic Assoc.,Montreal, Canada. (Miss J. H. Waters,P.O. Box 1668, Grand Central Station,New York 17.)

31-3. Mathematical Assoc. of America,40th summer meeting, Salt Lake City,Utah. (H. M. Gehman, MAA, Univ. ofBuffalo, Buffalo 14, N.Y.)

31-4. Haematin Enzymes, symp. (byinvitation), Canberra, Australia. (A. H.Ennar, John Curtin School of MedicalResearch, Australian National Univ.,Canberra.)

September

1-3. Association for Computing Ma-chinery, natl., Cambridge, Mass. (J. Mosh-man, Council for Economic and IndustryResearch, Inc., 1200 Jefferson Davis High-way, Arlington 2, Va.)

1-6. College of American Pathologists,Chicago, Ill. (A. H. Dearing, Suite 2115Prudential Plaza, Chicago 1.)

1-7. History and Philosophy of Science(General Assembly, History Div., Intern.Union of the History and Philosophy ofScience), Barcelona, Spain. (R. Taton,IUHPS, 64, rue Gay-Lussac, Paris 50,France.)

1-8. Acoustics, 3rd intern. cong., Stutt-gart, Germany. (E. Zwicker, Breitscheid-strasse 3, Stuttgart N.)

1-7. Oct. International Civil AviationOrganization (Meteorological Div.),Montreal, Canada. (ICAO, Maison deP'Aviation Internationale, Montreal.)

2-4. Allergy, 4th European cong., Lon-don, England. (British Assoc. of Allergists,Wright-Fleming Inst., St. Mary's Hospital,London, W.2.)

2-4. Cryogenic Engineering Conf.,SCIENCE, VOL. 129

-

Berkeley, Calif. (K. D. Timmerhaus,CEC, Chemical Engineering Dept., Univ.of Colorado, Boulder.)

2-4. Crystal Imperfections and theChemical Reactivity of Solids (Faradaydiscussion), Kingston, Ontario, Canada.(Faraday Soc., 6 Gray's Inn Sq., London,W.C. 1, England.)

2-5. American Mathematical Soc. andMathematical Assoc. of America (jointsummer), Salt Lake City, Utah. (E.Pitcher, AMS, Lehigh Univ., Bethlehem,Pa.)

2-8. Foundations of Mathematics: In-finitistic Methods, symp., Warsaw, Poland.(A. Mostowski, Dept. of Mathematics,Univ. of California, Berkeley 4.)

2-9. British Assoc. for the Advancementof Science, 121st annual, York, England.(Secretary, BAAS, 18 Adam St., Adelphi,London, W.C.2, England.)

3-6. American Sociological Soc., natl.,Chicago, Ill. (D. Young, Russell SageFoundation, New York 22.)

3-5. Nephrology, 1st intern. cong., Ge-neva, Switzerland, and Evian, France. (G.Richet, Hospital Necker, 149, rue deSevres, Paris 7e, France.)

3-9. American Psychological Assoc.,annual conv., Cincinnati, Ohio. (R. W.Russell, APA, 1333 16 St., NW, Wash-ington 6.)

4-7. International Federation of Sur-veyors, annual (by invitation), Gracow,Australia. (IFS, 4, Kanaalweg, Delft,Netherlands.)

5-11. Application of Radiation Sourcesin Industry, intern. conf., Warsaw, Po-land. (P. Fent, IAEA, Vienna, Austria.)

6-12. Standards on a Common Lan-guage for Machine Searching and Trans-lation, intern. conf., Cleveland, Ohio.(Secretariat, Center for Documentationand Communication Research, WesternReserve Univ., Cleveland 6.)

6-12. World Confederation for Physio-therapy, 3rd intern. cong., Paris, France.(A. Nicolle and J. Dupuis-Deltor, Societed'Organisation des Congr~s Frangais etInternationaux, 1, rue Chanez, Paris 16e.)

7-9. Psychometric Soc., Cincinnati,Ohio. (P. H. DuBois, Washington Univ.,St. Louis 5, Mo.)

7-9. Society of General Physiologists,Urbana, Ill. (F. G. Sherman, Dept. ofBiology, Brown Univ., Providence 12,R.I.)

7-10. Institute of Management Sci-ences, Paris, France. (A. S. Manne, Dept.of Economics, Yale Univ., New Haven,Conn.)

7-11. American Soc. of Clinical Pa-thologists, Chicago, Ill. (C. E. Wells, 2052N. Orleans, Chicago 14.)

7-11. Illuminating Engineering Soc.,annual natl. conf., San Francisco, Calif.(A. D. Hinckley, IES,, 1860 Broadway,New York 36.)

7-12. European Soc. of Haematology,cong., London, England. (E. Neumark,Dept. of Pathology, St. Mary's Hospital,London, W.2.)

7-12. World Medical Assoc., 13th gen-eral assembly, Montreal, Canada. (WMA,10 Columbus Circle, New York 19.)8-15. Sociology, 4th world cong., Milan

and Stresa, Italy. (Intern. SociologicalAssoc., Skepper House, 13 Endsleigh St.,London, W.C.1, England.)

LINDE'S fully portable LNR-25BLiquid Nitrogen Refrigerator is themost reliable cold storage unit inexistence. This rugged stainless steelcontainer has no mechanical opera-ting parts and thus is essentiallymaintenance-free - eliminates dam-aged samples caused by powerfailures.

It weighs only 60 lbs. empty, yetholds 28.5 liters of liquid nitrogenand 392 cu. inches of stored samples.A special LINDE insulation holdsevaporation loss to only 3% a day.On a single charge of nitrogen, it willkeep samples at -920F. for 34 days,directly immersed in the liquid, orfor 23 days in sealed tubular basketssuspended in the liquid. The large-diameter neck tube permits quickand easy access to the interior.Linde Company manufactures a

full line of containers (including the161/2 cu. ft. storage capacity LNR-640Refrigerator), accessories and othercryogenics equipment for the storageand handling of liquefied atmos-pheric gases. For information on theLNR-25B Refrigerator or otherequipment, mail the coupon.

Typical uses:* preservation of enzymes, hormones, proteins* pharmaceutical and chemical research* storage of bacteria cultures without labori-

ous transplanting* preservation of cancer cells for research* shrink fitting small metal production parts* cold storage of aluminum rivets and metal-

lurgical samples* immediate freezing of animal glands

CONSTRUCTIONCutaway shows interior arrangement of stor.age baskets in the LINDE LNR.25B and itsconstruction. Baskets are easily and quicklywithdrawn through wide-entrance tube. All.stainless welded construction and superior in.sulation make it both portable and durable.

NO Hinged CapBasket Support RodLifting HandleSpecial LINDE InsulationProduct Storage Basket

S Removable Neck TubeBasket Spacer

I Linde Company, Division of Union Carbide Corporation Dept. SC-63| 30 East 42nd Street, New York 17, N. Y. |I Please send me complete information on I| 0 the LNRW25B refrigerator ITRADE -Alea other equipment for liquefied atmospheric gases |

(please specify)

Firm Name IAddressAdrss "Linde" andI Cit"U Zone State --Union Carbide" are registered trade.

.j________________________1 marks of Union Carbide Corporation.168719 JUNE 1959

ANNOUNCING

SUBCELLULARPARTICLES

The fifth annual symposiumpublication of the Society ofGeneral Physiologists

TERU HAYASHI,Editor,with 20 Contributors

This new book is a comprehensive review ofthe most recent research on cell inclusions.Emphasis is on the structural aspects of sub-cellular particles as related to their function,especially with regard to the properties of theheterogeneous system created by the verypresence of the particulate material within thecell.

Improved, coordinated techniques in ultra-centrifugation, electron microscopy, andmicrochemical analysis have been used to estab-lish a more definitive correlation between par-ticles or their component parts and their ac-tivities within the cell. Authoritative data aregiven on the problem of cellular structure andits effect upon biochemical reactions. 94 ills.,213 pp. $6

Other S. G. P. Symposia-PHYSIOLOGICAL ADAPTATION

G. Ladd Prosser, Editor, with 14 Con-tributors. 92 ills., tables; 180 pp. $4INFLUENCE of TEMPERATURE on

BIOLOGICAL SYSTEMSFrank H. Johnson, Editor, with 24 Con-tributors. 133 ills., tables; 265 pp. $4.50

PHYSIOLOGICAL TRIGGERSand Discontinuous Rate Processes

Theodore H. Bullock, Editor, with 16Contributors. 5s ills., tables; 174 pp. $4

ELECTROLYTES inBIOLOGICAL SYSTEMS

Abraham M. Shanes, Editor, with 11 Con-tributors. 128 ills., tables; 238 pp. $4

JUST PUBLISHED!

Cell, Organism, and MilieuThe 17th Symposium of the Society for thieStudy of Development and Growth. Bookfocusses on the study of cell and tissue dif-ferentiation and growth in response to achanging chemical environment. Discussesmuscle cell models, tissue response to hormonalmilieu, growth factors operating on plant tis-sues, etc. Dorothea Rudnick, Editor, with11 Contributors. 135 ills., 352 pp. $8

Developmental CytologyThe 16th Symposium of the Society for theStudy of Development and Growth. Surveyscellular structure and function, especially aspertaining to differentiation processes and theirgenetic control. Covers important advances incell biochemistry, immunochemistry, electronmicroscopy, cytogenetics, etc. Dorothea Rud-nick, Editor, with 10 Contributors. 58ills., tables; 213 pp. $7Publishers of the Chronica Botanica Books

ORDER DIRECT FROM:

1688

LettersScientists Need a Group Opinion

I was pleased by Fletcher Watson'ssympathetic and generally favorable re-view of my book Science and Educationat the Crossroads [Science 129, 459(1959)]. One comment of his merits aresponse. He said that my suggestions"would require marked changes in pub-lic opinion; how these could be obtainedstill eludes many already immersed inthe problems."

Watson's statement does not makeclear which "public('s) opinion" he re-fers to. My book was written to helpscientists formulate their own scientific(public or group) opinion (about pro-fessional policies-not about scientificmatters) by doing two things: (i) set-ting up some clear-cut debating topicsabout "housekeeping" philosophy whichcould focus discussion, and (ii) describ-ing the "housekeeping" (administrative)machinery that scientists must create toenable them to continuously formulatetheir own group opinion about scientificand educational policies.

Until these steps are taken, sciencecannot hope to guide the general pub-lic's opinion. At present much of thescience and education news the publicreceives from radio, television or in thepress is, or seems to be, mutually con-tradictory. Information theorists wouldsay that the noise/message ratio is high.Hence the general public gets very littleguidance from science to assist it informulating its opinion. A great deal ofthis confusion would be reduced if sci-entists were spending a little more oftheir time than at present working ontheir administrative or political "house-keeping" problems. The AAAS has takensome generally correct, but in my opin-ion still too small, steps toward reachingthe goal that United States science needsto reach as rapidly as possible. It's laterthan we think.

JOSEPH W. STILL226 W. Court Street,Doylestown, Pennsylvania

Loyalty Oath

I should like to commend the reviewin the 6 March issue of Science [129,625 (1959)] of recent efforts to rescindthe loyalty oath provision of the Na-tional Defense Education Act.

I noted with interest the remark thatscientists and scientific societies had notyet taken a stand on this issue and thattheir silence had been attributed to tim-idity. For the record, I should like toreport that at its last meeting in Januarythe Council of the Federation of Amer-ican Scientists recorded its opposition to

this loyalty oath requirement and in-structed the executive committee of theFAS to communicate these sentimentsto the Congress. Letters supporting re-peal of this requirement have been sentto the sponsors of several of the billsthat have been introduced for this pur-pose. In these we have expressed ouropposition to the extension of loyaltytests to persons other than those whohave access to secret information or whohold positions in which they may bytheir decisions and actions affect directlyand substantially the national security.We have also expressed our particularfear that the antisubvqrsion affidavit re-quirement in the National Defense Edu-cation Act will tend to inhibit free in-quiry, association, and exchange of ideasamong students and faculty.

AUGUSTUS H. FoxFederation of American Scientists,Washington, D.C.

What Is a Profession?

In his letter, Hanor A. Webb speaksof two young scientists with majors inchemistry and biology [Science 129 746(1959)]. He then says: "These youngpeople are specialists but they are notprofessionals. Professions . . . requirecertification. . . ."A profession is determined not by cer-

tification but by training, code of ethics,and viewpoint toward the field of theprofession. Historically, there are three"learned professions"-medicine, theol-ogy and law. Theology is not certified.

Profession is defined in Webster's NewInternational Dictionary as "The occu-pation, if not purely commercial, me-chanical, agricultural, or the like, towhich one devotes oneself; . . . as, theprofession of arms, of teaching, of chem-ist." It is of note here that the profes-sion is "of teaching," not "of education."The sections of the AAAS are an ex-

cellent list of scientific professions:mathematics, physics, chemistry, astron-omy, geology, geography, zoology, bot-any, anthropology, psychology, socialsciences, engineering, medicine, agricul-ture, education. Only three of these re-quire certification, namely, medicine,education and, in some states, engineer-ing. But the certification did not makethem professions.

No, a profession requires training, aminimum of not less than four years ofcollege with major work in the field ofthe profession and minor work in re-lated fields. In addition to the basic col-lege work, experience working either inthe profession or for an advanced de-gree, doing original work, is needed be-fore a person becomes a true professional.

Next, a profession requires a code ofethics either stated or observed in thefield. For one such code in the profes-

SCIENCE, VOL. 129

sion of chemistry (that of the AmericanInstitute of Chemists) reference can bemade to The Chemist [35, No. 4, 125(April 1958) ].And last, a professional person will

have pride in his profession and its ac-complishments and live by the code ofethics of his profession. A true profes-sional would never attempt to step intosuch fields as Webb suggests for thechemist or biologist in his letter, certifi-cation or no. But if the professional hasthe ability to teach, he will and can doa better job teaching his field than can aperson with one or (in some cases) nocourse in that subject. A prime requisitefor teaching is a great deal more knowl-edge of the subject matter than will everbe needed for the class. The teachingprofession needs more instruction in thesubjects to be taught rather than in howto teach. Certification does not makeone a professional; one's viewpoint andtraining do.

W. W. BENTON2069 Watson Avenue,St. Paul, Minnesota

Shutoff Pulse Illusion

The "shutoff pulse illusion" describedby R. L. Ives in the 30 January issue ofScience [129, 272 (1959)] is clearly thetemporal analog of the well-known Machspatial gradient ("Mach ring") effect[E. Mach, Sitzber. Akad. Wiss. Wien,Math. Naturw. Kl. Abt. Ha 52, 303(1865)]. Ives has drawn two-dimensionalspatial patterns to illustrate diagram-matically the time-intensity course of thepulsed signals he used.The direct comparability of Ives' tem-

poral gradients with Mach's spatial grad-ients is borne out by the fact that if oneactually stimulates the eye with two-di-mensional spatial patterns of preciselythe forms diagrammed by Ives, one per-ceives spatial brightness variations of thesame kind as the perceived temporalvariations described by Ives as the "shut-off pulse illusion." Similar stimulus pat-terns of many degrees of complexitywere, as a matter of fact, designed andused by Mach to establish the empiricalrelations between perceived brightnessand the derivative functions of the spa-tial distributions of light intensity. Thespatial distributions used by Mach in hisexperiments are illustrated in his articleand are reproduced in some of his otherpapers [Sitzber. Akad. Wiss. Wien, Math.Naturw. Kl. Abt. Ha 54, 131 (1866);Vierteljahr. Psych. 2, 38 (1868)]. In thesame connection, it is also of interest tonote that Ives' diagrammatic represen-tation of his time stimuli and their asso-ciated perceptual effects are remarkablysimilar to Vivian O'Brien's analogousrepresentations of spatial patterns thatgive rise to Mach rings. See Fig. 9 of19 JUNE 1959

O'Brien's paper on contour perception[J. Opt. Soc. Am. 48, 112 (1958)].

Mach's analysis of perceptual effectsof this type led to his brilliant deduc-tion that the phenomena could be ex-plained only by assuming mutual inter-actions among adjacent retinal positions

a concept which has in recent yearsreceived direct confirmation from elec-trophysiological studies of neural activ-ity. See, for example, papers by Hart-line [Harvey Lectures 37, 39 (1941-42)]and Hartline, Wagner and Ratliff [J.Gen. Physiol. 39, 651 (1956)]. Theseinteraction effects actually serve to en-

hance brightness and color differencesbetween adjacent stimuli, whether theproximity is spatial or temporal (as inIves' example). Because of this differen-tial enhancement these effects are basicto the fineness of visual discriminations,and hence, as Hering emphasized, arebasic to veridical visual perception ofboth contours and temporal sequences inthe everyday discriminations of boundarychanges in the visual field.

DOROTHEA JAMESONLEO M. HURVICH

Department of Psychology,New York University, New York

1689

T

M20

WITH CAMERA II

WITH CINETUBE

PHASE CONTRAST EQUIPMENT

M20MICROSCOPE... available with sextuple revolvingnosepiece if desired, 20-Watt built-inillumination, superior Swiss quality incraftsmanship and optics.... with Camera II, permits continuousbinocular observation. Phototubedeflects 25% of light to binocular tube.Special format indicating eyepiece pro-vides rapid, perfect focusing....with Wild Cinetube, using any 16mmmovie camera having 50mm or 75mmfocal lengths, permits critical focusingon specimen while exposing film. Twobuilt-in beam splitters and photoelectriccell for exposure determination (withgalvanometer). Internal projection tubefor titling.... with Phase Contrast, Incident Light,Varicolor and other equipment.UNMATCHED VERSATILITY, PRECISIONAND UTILITY FOR RESEARCH AND

SCIENTIFIC EXPLORATION.4The FIRST name in Surveying Instruments,Photogrammetric Equipment and Microscopes

Booklet M20 mailed on request.

Full FactoryServices

_ _E E BRU G INSTRUMENTS, INC.

Main at Covert Street 0 Port Washington. New YorkPOrt Washington 7-4843

In CanadaWild of Canada Ltd., 157 Maclaren St., Ottawa, Ontario

New ProductsThe information reported here is obtained

fronm manufacturers and from other sources con-sidered to be reliable, and it reflects the claims ofthe manufacturer or other source. Neither Sciencenor the writer assumes responsibility for the accu-racy of the information. A coupon for use in mak-ing inquiries concerning the items listed appearson page 1694.

* PULSE-HEIGHT ANALYZER accepts pulsesof either sign up to a maximum rate of1600 per second. The system's memorycan be divided into either 100 or 150channels; the energy scale may be eitherlinear or exponential. The Hutchinson-Scarcott principle is used; information isstored in two torsional acoustic delaylines. The analyzer can subtract countsfrom a spectrum already in the memory.In conjunction with a live-time integra-tor, background count can be automati-cally subtracted from a spectrum. Read-out facilities include an analog outputfor pen recorder and automatic printingin decimal form on adding-machine tape.(Marshall, Dept. 856)

*TRANSISTOR TESTER permits measure-ment of the transistor beta parameterwhile the transistor remains in the cir-cuit. The tester will also measure betaand collector leakage current parameterswith the transistor removed from thecircuit. The unit operates either fromself-contained batteries or from linepower. (Sierra Electronic Corporation,Dept. 871)

* MAGNETIC TAPE RECORDER featuresseven channels of information with I-Mcy/sec bandwidth. Tape width is I/2in. Tape speed is 120 in./sec, whichallows 12 min of running time withstandard 1-mil tape. Timing is repro-ducible to ±0.005 percent. Peak flutterand wow are ± 0.1 percent or less. Start-ing time from rest to full speed is 4 sec.Input impedance is 93 ohm, and inputvoltage of 0.1 v peak-to-peak is required.Output signal level is 2 v at 93 ohm.(Minnesota Mining and ManufacturingCo., Dept. 872)

* PARAMETRIC PREAMPLIFIER for the 350-to 500-Mcy/sec range, when coupled toa conventional ultrahigh frequency re-ceiver, achieves over-all receiver noisefigures below 1.0 db with bandwidths ofapproximately 1 percent. The varactorwhich is used as the working element ofthe parametric amplifier is said to berelatively insensitive to radio-frequencyburnout and cross-modulation effects.(Microwave Associates, Inc., Dept. 874)

PRESSURE-SWITCH TRANSDUCER iS ca-pable of sensing pressure levels of from0.5 to 4000 lb/in.2 by interchange ofinternal modular components. Eightswitches will cover the entire range.Calibration is accomplished by rotationof an external pressure-setting adjust-

1690

You stirwithoutvacuum lossin all normalvacuumdistillations, *when you useKontesprecision-groundstirrers

* Shaft-bearing clearancesmeasured in ten-thou-sandths of an inch. Thisprevents vacuum lossand makes all Kontescomponent parts inter-changeable.

* Virtually friction-freeground surfaces; dia-mond-honed bearings.

a Borosilicate glass usedin all parts for addedstrength and longer life.(Teflon stirrer bladesavailable.)

* Convenient lubricantreservoir on bearing top.

* Inexpensive adapterspermit connecting shaftsto motors with chuckopenings as small as 14"*Ask about special KontesStirrers for exceptionallyhigh vacuum appli-cations.

Order now forimmediate deliver-s!

Write for free copy of CatalogTG-1SA describing all KontesTechnical Glassware, includingcomplete line of Stirrers.K.78100, complete with Ibearing, shaft and stirrer blade.Specify capacity of flask to be

T Price,ea24/40 17.8529/42 18.1034/45 18.6545/50 20.30

Above prices do not includeadapter or retainer.

Ask about dollarvalue discounts!

KONTESGLASS COMPANY

Vineland, New JerseyFirst Choice For Quality Technical Glassware

Midwest Distributor: Research Apparatus, Inc., Wauconda, IllinoisSCIENCE, VOL._ 129