Ordinary photograph ofcharred paper shows no

evidence of fingerprints~~INFRAR'ED PHOTOGRAPHYalso fingerprints potassium

in used motor oilIn police laboratories, infrared photography reveals

, fingerprints on a scrap of charred paper. In Hollywood,it gives moonlight effects at high noon. Over the tim-berlands, lumbermen use it to classify their crops.And in Brooklyn, Socony-Vacuum Laboratories use

infrared-sensitive plates to hunt for 48 different elementsin used oils. Twice a year, Socony-Vacuum gets back itsspectrographic equipment investment in savings overolder methods of analysis.

Its Technical Service Department records on a singleKodak Spectroscopic Plate, Type I-N, the entire gamut

5 from the four phosphorus lines at 2550A to the sensitivepotassium lines at 7665A and 7699A. Aside from thespeed of the analysis (two elements per minute), the48-element scope of the analysis, made possible by thewide-open receptiveness of photography in general andthe wide spectral sensitivity of this emulsion in particu-

j ;; lar, makes each plate a storehouse of "bonus" informa-tion-to be tapped immediately or at any later time.Kodak Spectroscopic Plates and Films come in 104

different varieties. For information about them, write forthe new edition of the booklet, "Kodak Sensitized Mate-rials for the Scientific and Industrial Laboratory."Eastman Kodak Company, Industrial Photographic Divi-sion, Rochester 4, N. Y.

SPECTROGRAPHY... an important function of photography

UNIVERSITY PRESS

Time's Arrowand Evolution

By HAROLD F. BLUM

Dr. Blum uses "time's arrow", the secondlaw of thermodynamics, as a key concept toshow how the nature and evolution of thenonliving, world place limits upon the natureand evolution of life. "A most stimulating,analysis of the physical and chemical con-ditions which seem required, as far as pres-ent knowledge goes, for the origin of life."-Sewall Wright. Illustrated, $4.00

Powell of theCo orado

By WILLIAM CULP DARRAH

An exciting biography of John WesleyPowell-the first American explorer of theunmapped Colorado River and one of theearliest government leaders to take an en-lightened view of the Indians. "The bestbook on Powell in print. A fascinating, studyof an extraordinary man."-San FranciscoChronicle. "More than a biography of oneman, it is an American saga."-N. Y.Herald Tribune. Illustrated, $6.00

At your bookstore,

PRINCETON UNIVERSITY PRESS

The familiar C & B trademark is your assurance thatthe produtct carrying this mark

(1) has been manuifactured to meet the standards andspecifications stated upon the label.

(2) has passed otur specifications prior to packagingand has been rechecked after packaging.

(3) is backed by an organization which, for overthirtv years, has had as its primary aim the productionof Laboratory Reagents of the highest purity.

C & B Products are distributed byLaboratory and Physician Supply Houses

Throughout the World

Write for copy of catalog. The COLEMAN & BELL Co.Manufacturing Chemists, Norwood, O., U.S.A.

October 12, 1951

11

II

11

HOTEL RESERVATIONS

118th AAAS MEETINGPhiladelphia, December 26-31, 1951

The list of hotels and the reservation coupon below are for your convenience in making your hotelroom reservation in Philadelphia. Please send your application, not to any hotel directly, but to theAAAS Housing Bureau in Philadelphia and thereby avoid delay and confusion. The experienced HousingBureau will make assignments promptly; a confirmation will be sent vou in two weeks or less. Share a

room with a colleague if you wish to keep down expenses. Mail your application now to secure your

first choice of desired accommodations.

HOTELS AND RATES PER DAYHotel* Single

ADELPHIA* $5.00-$6.00BARCLAYBELLEVUE-STRATFORD* $4.50-$6.00BENJAMIN FRANKLIN* $5.00-$7.50DRAKE $6.00ESSEX $4.75-$5.00JOHN BARTRAM* $3.25-$4.50PENN SHERATON $5.00-$7.50RITZ-CARLTON* $7.00-$7.50ROBERT MORRIS $4.50-$5.00ST. JAMES $4.00-$5.50SYLVANIA*WARWICK

Cots added to a room are $2.50 each; dormitory style

Double Twin-Bedded$7.50-$10.50 $10.00-$12.50

$ 8.00412.00$8.00-$10.00 $ 9.00-$12.00$8.00-$10.50 $11.00-$13.00

$ 7.00 $ 9.00$6.00-$ 8.50 $ 9.00-$10.00$5.00-$ 8.00 $ 7.00-$ 9.00$7.50-$10.00 $ 8.00-$10.50

$11.00-$12.00$7.00-$ 8.00 $ 8.00$6.00-$ 8.00 $ 6.50-$ 9.00

$ 9.00-$11.00$ 9.00-$12.00

rooms (for 5 or more) are $3.50 per person.* Hotels starred have sessions in their public rooms. For a list of the. headquarters of each participating society and section,please see Association Affairs, Science, August 24, or The Scientific Monthly, September.

X-----------THIS IS YOUR HOTEL RESERVATION COUPON ---A.AAS Housing BureauArchitects Building (1st Floor) Date of Application ................

Philadelphia 3, Pa.Please reserve the following accommodations for the 118th Meeting of the AAAS:

TYPE OF ACCOMMODATION DESIRED

... Single Room(s)

. . -Double Room (s)

Desired Rate ........ Maximum Rate.

Desired Rate ........ Maximum Rate ......... Number in Party

... Twin-Bedded Room(s) Desired Rate ......... Maximum Rate.

Desired Rate ......... Maximum Rate. Sharing this room will be:

........... (Enumerate persons here and attach list giving name and address of each person, including yourself)

CHOICE OF HOTEL

First Choice .. ..... Second Choice ... ....... Third Choice.

DATE OF ARRIVAL ................ DEPARTURE DATE ...........................

(These must be indicated)

NAME ........................................... ...............................................(Please print or type)

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

(Street) (City and Zone) (State)

Mail this now to the Housing Bureau. Rooms will be assigned and confirmed in order of receipt of reservation.

Suites$25.00-$35.00$14.00-$25.00$20.00-$30.00

$18.00$15.00

$12.00-$15.00

$18.00$22.00-$24.00

. . Suite (s)

October 12, 1951 is

]1iiilllliiltI}llg"lPOSITIONSWANED IiiiiiiiiiiiiiiiiiBiologist: Ph.D. Feb. 1952 (Endocrinology-Physiology). Academicor research; experienced in both. Complete biological backgdroued;completelx ad1ablCe Available immediately. Eastern area onlyIo19, S;l.CE.X

Chemist: Ph.D., presently professor university physical chemistrydesires to make change. College or university appoiiitmesit withrank preferred: industrial position considered. Extensive teachlinlgexperience coupled with broad training. Excellent command Russianand German. Box 9, SCIENCE. 9/28, 10/12

Position Wanted:Pharmacologist; Ph.D.; two years' straight research; eight years'teaching; considerable administrative experience; interested inindustry or university administration; for further iniformation,please write Scien.'e Division, Medical Bureau (Burneice LarsonDirector), Palmolive Building, Chicago.

Physiologists (2) Husband and wife. Desire teaching/researchposition in Northeast. Husband's experience: B.S. organic andbiological chemistry, 4 years commercial research (enzymes andantibiotics) 4 years clinlical lab officer (Army), M.S. physiologymajor, pharmacology minor Ph.D. physiology major, pharmacologyminor. Wife's experience: i.S. pharmacy, M.S. physiology major,pharmacology minor, Ph.D. physiology major, pharmacology minor,4j years dental and nursing teaching experience. Opportunity forown mammalian research a requirement. Available June, 1952.Box 16, SCIENCE. X

Virologist, M.D. or Ph.D. Research, no routine diagnostic work;teaching optional. Experience in neurotropic viruses, poliomyelitis,tissue culture and animal work. Senior permanent position inmedical school. Box 14, SCIENCE. 10/19

AVOID DELAY . . . . Cash in Advance paymentMUST be enclosed with ALL classified ads.See "Charges and Requirements"

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Biochemists: Research Institute, East, has opportunities for youngPh.D.'s in projects involving (1) protein fractionation, electro-phoresis, ultracentrifugation, (2) characterization and isolation ofmicrobiological growth factors. Experience in respective fields de-sired. Please give brief history. Box 558, SCIENCE. 10/12

Chemist or Chemical Engineer: Graduate work helpful but not es-sential. Must have good personality aiid approach, be alert andwith active imagination along chemical lines. Work will be con-tacting industry and government agencies to develop sales of newproducts and the opportuniities for manufacture of new products.Applicants should supply full particulars on education, experience,previous employment, usual personal information. and salary de-sired. Write Box S 1603, 221 W. 41 St., N. Y. 18, N. Y. 10/26

14

11111111111111111111111111POSITIONS OPEN wlllltIiiiiiiiiiiiiiIlPositions Open:(a) Assistant in Endocrine Cancer Research; M.D., preferably in-ternist; important research institution; university medical center.(b) Chemist, Ph.D., trained in protein chemistry preferably withminimutm three years' experience; industrial research; large city,university med:cal centes; Midwest; $6000-$8000. (c) LaboratoryDirector; preferably woman, M.S. or Ph.D., interested research;duties incluide teaching; medical school department; around $5000.(d) Senior Pharmacologist; Ph.D. or M.D. with pharmacologicalresearch experience; should be quarified to initiate and developpharmacological research program; pharmaceutical company; East.(e) Graduate in one of Biological Sciences to develop bioassayprocedures for pituitary hormones; advantageons if qtualified con-duct hypophysectomies in laboratory animals, well known researchinstitution; university medical center; $6000, (f) Biochemist withpractical training in plhysiological chemistry and toxicology; Ph.D.preferred; fairly large hospital; Pacific Coast. S102- Science Divi-sion, Medical Bureau (Burneice Larson, Director) PalnoliveBuilding, Chicago. X

]LANGUAGES Iiiiiil

Listen and Learn a Language by LINGUAPHONEAt home learn to speac Spanish, French, German, Ruian, thAsiatic languages by quck easy Linrpone Converational Method.Save time, work, money. Send for free book today.

Approved for VETERANS' TrainingLINGUAPHONE INSTITUTE * 8410 Rekwf.ller Plaza, NMw York 20

WANTED TO PURCHASE . . . Sets and runs. foreilnP PERIODICALS ~ and dmestic. EntiretIENTIFIC PERIODICALS >libraries and smallerE TIC and BOOKS collections wanted.

WALTER I. jOHNSON * 125 East 23rd St., New York 10, N. Y.

Your sets and files of scientific journalsare needed by oui library atid institutional customers. l'lease sendus lists and descriptiois of periodical files you are willing to sellat high market pric;s. W'rite Dept. A3S, J. S. CANNX.R. INC.

_Boston 19, MlassachusttsMETHODS FOR THE STUDY OF THE INTERNAL

ANATOMY OF INSECTSThis voluime covers the dissection, staining anld mounting of the

internal organs and tissues of insects. Its special merit is a preciseorganizationi of text material making it a beginners' book for simpleeasy use. The fixatives, stains and mounting media are the simplest1nssible for resultobCbe obtained. A long use of over 25 years onhuindreds of iiisect species has proven its basic val-ue. The pricehas hadi to be raised to $3.00 post paid.

Department of Zoologg and Entomology, OhioCLARENCE H. KENNEDY State University. Columbus 10, Ohio. U.S..

SCIENTIFIC BOOKS and PERIODICALS WANTEDComplese libraries-Sets ond runs-nlge titles

Also, please send us ynur wrant lisis.STECHERT-HAFNER, INC.

.______________________ 31 East 10th St., New York 3

SCIENCE, VOL. 114

I PERSONNEL PLACEMENTYOUR ad here reaches over 32,000 foremost scientistsin the leading educational institutions, industriallaboratories, and research foundations in the U. S.and 76 foreign countries-at a very low cost

CLASSIFIED: 15¢ per word, minimum charge $3.00 Use ofBox Number counts as 10 additional words.

DISPLAY: $17.50 per inch, no charge for Box Number.Correct payment to SCIENCE must accompany all ads.Insertion usually made 2 or 3 weeks after receipt of ad.SCIENCE * 1515 Mass. Ave., N.W., Wash. S, D. C.

-The MARKET PLACE-BOOKS * SERVICES * SUPPLIES * EQUIPMENT

YOUR ad here reaches over 32,000 foremost scientistsin the leading educational -institutions. industriallaboratories, and research foundations in the U. S.and 76 foreign countries-at a very low cost

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DISPLAY: Rates listed below-no charge for Box Number.Monthly invoices will be sent on a charge account basis

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7 times In 1 year 16.00 per inch13 times in 1 year 14.00 per Inch26 times in 1 year 12.50 per inch52 times in 1 year 11.00 per inch

For PROOFS on display ads, copy must reach SCIENCE 4weeks before date of issue {Friday of every week).

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4 1 replies received from ONEclassified ad in SCIENCE . . .Your ad here will get results!

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YOUR ad hre reaches over 32,000 foremost scientistsin the leading educational institutions. industriallaboratories, and research foundations in the U. S.and 76 foreign countriesat a very low cost

CLASSIFIED: 20¢ per word, minimum charge $5.00. Use ofBox Number counts as 10 additional words. Correctpayment to SCIENCE must accompany ad.

DISPLAY: Rates listed below-no charge for Box Number.Monthly invoices will be sent on a charge account basis

-providing iatisfactory credit is established.Single Insertion $17.50 per inch

7 tinres In 1 year 16.00 per inch13 times in 1 year 14.00 per inch26 times in 1 yew 12.50 per Inch52 times In 1 yea 11.00 per inch

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f4re zoe4* MICROSCOPES* MICROTOMES* REFRACTOMETERS

Equipment for PhotomicrographySpecialists ix Leitz and Zeiss EquipmentWrite to

|ERIC SOBOTKA CO. * 102 West 42nd Street[i~~TOBOTKA We -New York 18, N. Y._

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Range 1.2 to 7.5 Specific GravityFor the Determination of Specific Gravity

ofMinerals-Gems-and other substances.

Write for leaflet HL-SR. P. CARCILLE 118 Liberty St., New York 6, N. Y.

"Your animal is half the experiment"SWISS ALRNO MICE.AILBINO- W RATS

albino far s P. 0. BOX 331Dept. A RED BANK, N. J.

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PROPPER MANUFACTURING CO., INC.10-34 44tt Drive, Long Island City New York

White SWISS Mice 20c UadRabbits, Cavies, White Rats, Ducks, Pigeons, Hamsten

Write . J. E. STOCKER . Ramsey, N. J.

Entries in the Fifth International Photography.in-Science Salon, sponsored annually by TIizSCIENTIFIC MOONTHLY and the Smithsonian In-stitution, should be sent (prepaid) to the Edi-tor, The Scientific Mlonthly, 1515 MassachusettsAve., N.W., Washinigton 5, D. C., Nov. 1-Nov.27. All aiccepted plhotographs will be shown atthe AAAS miieetintg in Philadelplhia Dec. 26-31,anid later throughbout the U. S. For entry blanksand full information write to the address givenabove.

October 12, 1951

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Shipped to all points via Air ExpreFor further information write

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GLASS ABSORPTION

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Klett-Summerson Photoelectric Colorimeters-Colorimeters - Nephelometers'- Fluorimeters-Bio-Colorimeters -Comparators - Glass Stand-ards-Klett Reagen-ts.

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

MINIATUREMERCURY VAPOR LAMP

This miniature mercury vapor lamp hasa special glass housing to permit freepassage of the 1849A and 2437A lines.Provides good supply of short wave ultraviolet. May be used also for germicidalor ozone generating purposes. ManyColleges are using it as a monochromaticlight source (filters needed). Lamp sup-plied complete with socket and instruc-tions. Your Price $1.95

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NEW REVISED-ENLARGEDSNOOPERSCOPE BOOK

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SCIENCE, VOL. 114

YOUR ad here reaches over 32,000 foremost scientistsin the leading educational institutions. industriallaboratories. and research foundations In the U. S.and 76 foreign countries-at a very low cost

CLASSIFIED: 20t per word, minimum charge $5.00. Use ofBox Number counts as 10 additional words. Correctpayment to SCIENCE must accompany ad.

DISPLAY: Rates listed below-no charge for Box Number.Monthly invoices will be sent on a ciarge account basis

-providing satisfactory credit is established.Single Insertion $17.50 per inch

7 times in 1 year 16.00 per Inch13 times in 1 year 14.00 per inch26 times In 1 year 12.50 per Inch52 times In 1 year 11.00 per inch

For PROOFS on display ads, copy must reach SCIENCE 4weeks before date of issue (Friday of every week).

LaMOTTE BLOCK COMPARATORThis improved LaMotte

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Complete witlh aily one set of LaMotte Permanent ColorStandards, together with a supply of the correspondingindicator izolution, measuring pipette and marked test tubes.

LaMOTTE WATER SOLUBLE pH INDICATORS(Sulfon-phthalein series) pH 0 2-9 6

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Your voice

In

Davy

Jones'

locker

To strengthen voices in the newest submarine cablesbetween Key West and Havana amplifiers had to be builtright into the cables themselves. With the cables, theseamplifiers had to be laid in heaving seas; and they mustwork for years under the immense pressure of 5000 feetof water.

For this job, Bell Laboratories engineers developed anew kind of amplifier - cable-shaped and flexible, witha new kind of water-tight seal.

To serve far beyond reach of repair, they developedelection tubes and other parts, then assembled them indust-free rooms.

The two cables - each has but two conductorssimultaneously carry 24 conversations as well as currentto run the electron tubes.

With these deep-sea amplifiers, submarine cables carrymore messages . . . another example of how research inBell Telephone Laboratories helps improve telephoneservice each year while costs stay low.

r-----------------____________________________

BELL TELEPHONE LABORATORIES0 Exploring and inventing, devising and perfecting, for continued improvements ffi

and economies in telephone service.

Cuftaway view of deep-sea anmplifier. Tubes and other elemiients ar-e hautsed inplastic cases then enclosed in interleaved steel rings in a copper tube. Glasstape, armior wire and intpregnated fiber conmplete the sheath.

.z

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()

I

Having DiffiCulty

Selecting the RIGHTMICROSCOPE ILLUMINATO R?

Every microscope user has different needs, different likes and dislikes inilluminators. But whatever tvpe you prefer . - . remember, best results are assuredonly when the qualit) matches that of your microscope.

Despite the diversity in type, function, and appearance, there are certaincharacteristics you will find in all AO Spencer Microscope Illuminators . . . sturdy,precision construction . . . highest quality optics . . . brilliant, even illumination. . . proper heat dissipation for cool, comfortable operation.

AO distributors or representatives will welcome the opportunity to makerecommendations or discuss illumination problems with you. Just write Dept. X2.

A. BUILT-IN SUBSTAGE LAMPB. PORTABLE SUBSTAGE LAMPC. ADJUSTABLE LABORATORY LAMP

D. ADVANCED LABORATORY LAMPE. UNIVERSAL MICROSCOPE LAMBFF. CHALET TABLE LAMP

Since we are currently supplying bothmilitary and civilian needs, instrumentdeliveries cannot always be immediate.

INSTRUMENT DIVISION * BUFFALO 15, NEW YORK

.'-I~,2,<

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