for Partition Chromatographyand Paper Electrophoresis

A photoelectric precision instrument for the rapidand convenient evaluation of strips and sheetsof filter paper in partition chromatography andpaper electrophoresis.

Quality is more

than just a word... it signifips high standards

| andl proven reliability, whichmerit your confidence.

* AIINO ACIDS: PEPTIDES'VITAMIN FREE" CASEIN

HYDROLYSATE

* NUCLEOPROTEINS;--QUALITY -- PURINES, PYRI'MIDINES

MISCELLANEOUS

BIOCIIEMICALSV*ITAMINS-ENZY MIES

0-=- -t * GROWN'TII FACTORS

* STEROID HORMONES

BIOLOGICAL SALT

IMIXTURES* BIOLOGICAL TESTMATERIALS

N UT R I T IO N A L

L ~~BI O C H E M I C A L SCORPORATION

21010 Miles Avenue ... Cleveland 28, Ohio NewrCtaJuly 19

Over 1700 Ite?Write Dept. I1

7orlog)56msf02

A completely self-contained

gas analysis unit, priced within

reach of all analytical labor-

atories. Completely automatic.

Send for your copy of descrip-tive brochure.

F O R VAPOR PHASE CHROMATOGRAPHY

* A partition-elution apparatus* Efficiency of approximately 2000 theoretical plates* Each purified component can be recovered quantitatively* Operates on 2 to 200 milligrams of material

* Covers boiling point range from 0 to 3500 Centigrade

Catalog RE 13 describes t

the COMPLETE LINE OF IRIRECO CHROMATOGRAPHIC

equipment. Send for

you r copy tod ay.

'SEARCH EQUIPMENT CORPORATION

1135 Third Street, Oakland, California

6 July 195643

i

0 0

6 jtily 1956 43

ERSONNEL PLACEMENT

Bacteriologist, B.A., 1940; M.A., 1955. Broadacademic background-chemistry, mathematics,zoology, and so forth-14 years' experience inall phases of clinical bacteriology, parasitologyand serology. Publication now at press. Desiresresearch or clinical and research; presently em-

ployed. Box 166, SCIENCE. X

Pathologist, 40. Certified clinical and anatomicalpathology. Associate PrQfessor. Extensive surgi-cal pathology and cancer research. More than 50publications. Pennsylvania, Florida, Californialicenses. Category IV. Box 161, SCIENCE.

7/6, 13, 20

Physical Chemist, Ph.D.; 8 years as researchchemist in industry; 4 years' full-time universityteaching. Medical Bureau (Burneice Larson,Director), Palmolive Building, Chicago. X

Science Editor or Reporter. Man with a broadscientific and cultural background desires posi-tion doing science editing or reporting. Box 168,SCIENCE. 7/13

Ph.D. with Research Background in Agricul-ture, B.S. in entomology or plant pathology; tohead research with privately owned agriculturalchemical concern. Give biographical sketch.Salary open. P.O. Box 727, Salinas, Calif.

7/13, 20, 27

Bacteriological Technician, interesting work,40-hour week, no night calls. Pleasant environ-ment, air-conditioned. Write Personnel, Chil-dren's Hospital, Cincinnati 29, Ohio. 7/6, 13, 20

Research Worker trained in serologic techniqueswith some experience in immunochemistry. Sal-ary dependent on experience. Apply Box 164,SCIENCE. 7/13

SMALL ANIMALS FOR RESEARCHAn outstanding producer of small animals forresearch will consider the appointment of an as-sociate. Duties to include contacting researchgroups, acting as technical adviser on the farm,possible development of strains not now bred,and some administrative responsibilities. Train-ing in bacteriology, biology, or animal husbandrydesirable. Interest, personality, and enthusiasmimportant. After demonstrating ability, consider-ation will be given to active interest in theorganization. Write fully as to training, experi-ence, family, and expected income. Box 126,SCIENCE. 6/8, 22; 7/6

(a) Young Physician to serve as assistant direc-tor, department of clinical investigation, pharma-ceutical company; East. (b) Research Patholo-gist; research center in tropical country underAmerican auspices. (c) Immunochemist, pref-erably Ph.D., or biochemist trained in immunol-ogy; allergy laboratory with well-equipped re-search department; large city, medical center,East. (d) Pharmacist; important faculty posi-tion; Ph.D. or one with master's with somecourses toward doctorate; state university,Mid-west. (e) Research Biochemist, Ph.D., withevidence of capacity for original research; uni-versity research department; $5200-$5600;West. S7-1 Medical Bureau (Burneice Larson,Director), Palmolive Building, Chicago. X

The Market Pla-ceBOOKS * SERVICES * SUPPLIES * EQ2UIPMENT

BOOKS AND MAGAZINES

44

I ri

CLASSIFIED: 184 per word, minimumcharge $3.60. Use of Box Numbercounts as 10 additional words.

COPY for classified ads must reach.SCIENCE 2 weeks before date of Isue(Friday of every week).

DISPLAY: Rates listed below - nocharpe for Box Number. Monthlyinvoices will be sent on a chargeaccount basis-provided that satis-factory credit is established.

Single insertion $22.00 per Inch13 times in 1 year 21.00 per Inch26 times In 1 year 20.00 per Inch52 times In 1 year 19.00 per Inch

For PROOFS on display ads, copy mustreach SCIENCE 4 weeks before dateof issue (Friday of every week).

I0~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

CHEMICAL

ENGINEERExperienced chemical engineer re-

quired to conduct laboratory andplant scale investigations of prob-lems connected with the operation ofa gaseous diffusion plant. Ion ex-

change, solvent extraction, fluidsflow, solids handling, electrolysis,corrosion, metallurgy, mathematicalanalysis, and thermodynamic studies.Submit resume and salary require-ments to:

Employment Department

GoodyearAtomic Corporation

P. O. Box 628Portsnwuth, Ohio

INFRARED

SPECTROSCOPIST

Opening for a responsible indi-vidual with several years' indus-trial experience in infraredspectroscopy to head up an in-frared roup. Infrared activitiesare being carried out in a wellequipped, newly established lab-oratory as part of a cooperativeeffort to solve a wide variety ofphysical, chemical and metal-lurgical problems. Submit re-

sume and salary requirementsto:

Employment Department

GoodyearAtomic Corporation

P. O. Box 628

Portsmouth, Ohio

CLINICAL INVESTIGATIONLarge midwestern ethical pharmaceuticalcompany has opportunity for physician.Prefer man 30-40 with some training andexperience past internship. Experience inendocrinology especially desirable. Pleasesend complete resume to Box 165, SCI-ENCE. 7/13

DISPLAY: Rates listed below - nocharge for Box Number. Monthlyinvoices will be sent on a chargeaccount basis-provided that satis-factory credit is established.

Single insertion $22.00 per inch13 times in 1 year 21.00 per inch26 times in 1 year 20.00 per inch52 times in 1 year 19.00 per inch

For PROOFS on display ads, copy mustreach SCIENCE 4 weeks before dateof issue (Friday of every week).

Writers, for free lance writing in anthropology,biology, geology, and natural history. Ph.D. orequivalent training. Experienced writers only.Send background details. Box 158, SCIENCE.

7/6, 13, 20

WANTED ITO Sets and runs, foreign

SCIENTIFIC and domestic. EntirePERIODICALS libraries and smallera n d B OO K S collections wanted.

WALTER J. JOHNSON, INC.125 E. 23rd St., New York 10, N. Y.

POSMONS OPEN POSITIONSOPEN fill11111'111111111111

POSITIONS WANTED 11111111111111111

_

1111111111111111111111111 POSITIONS OPEN 111111111111111111111111

SCIENCE, VOL. 124

rThe MARKET PLACEBOOKS * SERVICES * SUPPLIES * EQUIPMENT

I . r~~~~~~~~~~~~ . . _,

jIIIIIiIIIIG BOOKS AND MAGAZINES |

Your sets and files ofscientific journals

are needed by our library and institutional cus-tomers. Please send us lists and description ofperiodical files you are willing to sell at high mar-ket prices. Write Dept. A3S, J. S. CANNER, Inc.

Boston 19, Massachusetts

SCIENTIFIC JOURNALS WANTEDSets, Runs and Volumes bought at top prices.

Your wants supplied fromour Back Files of over 3,000,000 periodicals.Abrahams Magazine Service; N. Y. 3. N. Y.

PROFESSIONAL SERVICESJ|ljllJ|lljI

|||||||||SUPPL1ES AND EQUIPMENT 11111111

||||||||SUPPLIES AND EQUIPMENT |||||||

THE JUNIORGarceau

ElectroencephalographPrice $575.00 complete.

No BatteriesRequires no Shielding

Prempt DeliveryA.C. OperatedInkless Writing

Shipped Ready to RonELECTRO-MEDICALLABORATORY, INC.

South Woodstock 2, Vermont

1

ALBINO RATSOur mass production methods insuregreatest uniformity and consistency

Price list on requestDAN ROLFSMEYER CO. * Ph. 6-6149

Route 3, Syene Road, Madison, Wisconsin

SEND FOR DETAILSON THE NEW,ULTRA-COMPACT

GME IARDY WARBURGAPPARATUS

CONSISTENT RATS & MICEBUDD MT. RODENT FARM

CHESTER, N. J.

Breeders ot a recognized strainof Wistar rats and W.S. mice

LOVINS MICRO-SLIDE FIELD FINDERf>|_ ~~Niow availalble directly from/ the mansfaeterer

'& * i FRN& *@tiU@

n50. M Y.U.S.A.

Write for details. W. & L. E. Gurley, Troy, N. Y.

||||||||| SUPPLIES AND EQIUIPMENT1|11|||

L

* "From the hand ofalbino rats the resarch"Hypophysectomized

RatsDescendants of the A lit

SOrgaue-Dawley andWistar Stratns a

0

HENRY L. FOSTER, D.V.M.President and Director

THE CHARLES RIVER BREEDING LABS.Dept. B, Wilmington, Mass.

STAINS-GURR'S-INDICATORSFREE PRICE LIST

ESSE LABORATORY SUPPLIES459 Bloor St., W. Toronto, Canada

EXO-KETONPATCCOVERSLIPSUNBREAKABLE

* WON'T CUT FGEMS* FLEXIBL Yet* WaU NOT CURLI* Y THE PRICE OF GLASS

Jlso ava&bI. ruough your local dealr

6 July 1956 45

M icroscopists:Send your name and address for in-

formation on* Cargille Non-Drying Immersion Oil* Allen Reference Sets (for microscopy) of

a) Mineralsb) Animal Hairsc) Fur Hairsd) Starches & Food Condiments

* High Index Mounting Medium* Index of Refraction Liquids (1.35-2.11)* Book: "Practical Refractometry

By Means of the Microscope"New pencil for marking glass, plastics,

mineral specimens with hairline marks,permanent if desired.

R. P. Cargille Laboratories, Inc.117 Liberty St. New York 6, N.Y.

Kilogram QuantitiesPURE CAPRIC ACID

No detectable unsaturatesNo C8 No C12

Also other high purity chemicalsAPPLIED SCIENCE LABORATORIES, INC.

140 N. Barnard St., State College, Pa. * AD 8-6282

HOLTZMAN RAT COMPANYTwo factors contribute to the success of our rats in tumor research: first, theinsignificant levels of spontaneous tumor incidence and second, the low percent oftumor implant regression. The latter especially applies to the Flexner-Jobling andWalker 256 Carcinomas and R-8, R-39 and Jensen Sarcomas.

Phone Alpine 6-5573

4

8

II

0

i

I

I

Rt. 4, Box 205 Madison 4, Wisc.

MONOIMOLECULARI LAYERiS

Edited by Harry Sobotka6 x 9 inches, 215 pages, 62 illustrations, index,

clothbound, April 1954Price $4.25. AAAS members' prepaid order price $3.75

A symposium volume of the American Association for theAdvancement of Science

The aim of this volume is to give a cross section of recent progress in thefield of monomolecular layers-on water surfaces, solid surfaces, and oil-waterinterfaces. The papers supply fundamental data for problems in lubricationand detergency, as well as for questions of biochemical concern such as thedetermination of molecular weights of proteins.

The variety and scope of the volume suggest that two-dimensional chem-istry should not be regarded as an isolated specialty, but that its methods andconcepts impinge on physical and colloid chemistry, on organic and biochem-istry; they contribute to analytical chemistry and to chemical engineering andtechnology.

The participants comprise some of the pioneer research workers in thisfield of chemistry. The papers review the work of others and report the con-tributions of the authors.

CONTENTSModern Film Techniques and Their Application

to Biochemical ReactionsThe Determination of Molecular Weights of

Proteins by the Horizontal Surface BalanceAlechanical Properties of the Surface Films on

Aqueous Solutions of DetergentsStudy of Adsorption at a Solution-Air Interface

by RadiotracersDeposited Radioactive MonolayersHydrophobic Monolayers and Their Adsorption

from Aqueous SolutionA Review of the Properties of Films at Oil-Water

InterfacesChemical Reactions of Simple and Mixed Mono-

molecular LayersChemical Reactions and Electric Potential in

AMonolayers

HANS TRURNIT, Army Chemical Center, Md.

E. MISHUCK and F. EIRIcHPolytechnic Institute of BrooklynA. P. BRADY and A. G. BROWNStanford Research Institute

J. K. DIXON, C. M. JUDSON, and D. J. SALLEYAmerican Cyanamid Co., Stamford, Conn.

D. E. BEISCHER, U. S. Naval Schoolof Aviation Medicine, Pensacola

ELAINE G. SHAFRIN and WILLIAM A. ZISMANNaval Research Laboratory, WashingtonE. HUTCHINSON, Stanford UniversityHMARY SOBOTKA and SHIRLEY ROSENBERGThe Mount Sinai Hospital, New YorkE. HAVINGA, University of Leiden

American Association for the Advancement of Science1515 Massachusetts Avenue, NW, Washington 5, D. C.

English Agents: Bailey Bros. & Swinfen, Ltd., 46 St. Giles High Street, London, W. C. 2

SCIENCE, VOL. 124

1.46

I

Dr. G. E. Moore, B. S., Syracuse(1935), Ph. D. in chemistry, Stan-ford (1940), came to the GeneralElectric Research Laboratory in 1946from Los Alamos, N. M. He hasspecialized in the fields of combus-tion and rocket propellants and isthe author of various papers on ther-mochemistry and thermodynamics.He has been head of the Laboi atory'scombustion research unit since 1955.

Research for better rockets

General Electric's Dr. George E. Moore applies basicstudies of combustion to development of propellants

Behind the use of rocket motors in such devices asguided missiles and earth satellites is a history ofpainstaking research into the fundamentals of com-bustion. Dr. George E. Moore's contributions to thiscomparatively new science have included calculationsof the effect of combustion-chamber size and shape onrocket efficiency, innovations in the use of fuels, andnew understanding of the general chemistry ofrockets. He and a group of General Electric associateshave devised a new type of "hybrid" motor-usingboth liquid and solid fuels-that is a model of simplicityand efficiency in rocket propulsion and promises toplay a significant role in what is certain to be a bigfuture for rockets.

As General Electric sees it, providing individualscientists with freedom and incentive to solve theproblems of research is part of solving the largerproblem of how we can all live better, with bettermaterials and better products with which to work,better jobs, and extra human satisfactions in termsof what people expect and want in life.

Prgress Is Our MoS, Impor/en' Troddcf

GENERALL ELECTRIC

IMPROVED MODEL, FANZ

I FE SHARPENER

> With electric motor drive and with automaticknife lifting and reversing device

1

4 Simplified operat-ing and sharpeningdirections are print-ed in white letteringon both sides ofhinged front doorpanel.

7203. Showing hood removedfrom knife mechanism.

M ICROTOME KNI FE SHARPENER, Fanz,Improved Model 53. With simplified, enclosedmotor drive and with Miller automatic knife lift-ing and reversing device. Takes knives up to 325mm in length arxd up to 13 mm thick. Providesmore nearly perfect cutting edge than skillful handhoning and stropping.A revolving glass disc, 21 inches diameter, is

driven against the knife which is automaticallyswept to and fro in an arc through the center ofthe disc surface. In each operation, the automaticdevice sweeps the knife across the glass disc forapproximately 27 seconds, during which period itmakes 4.5 reciprocating cycles, and is then lifted,turned over and lowered to the disc in approxi-mately 8 seconds, after which the process is re-peated on the opposite side. A scale on the knife

mechanism makes possible precise, reproduciblesetting of the angle of the bevel. Metal housing is25 inches square x 11 inches high and is finishedin attractive baked gray Hammertone enamel.

An early model of this Sharpener has been inconstant use for the past 23 years. During this periodmore than 16,000 knives sent to us for reconditioninghave been sharpened on this machine without repairsexcepting occasional replacement of a worn belt.

7203. Mlcrotome Knife Sharpener, Fanz, ImprovedModel, as above described, with Miller automatic knife lift-ing and reversing device, complete with glass disc, calibratedwooden wedge to facilitate adjustments; drip deflector, glass

reservoir 2 liter capacity, plastic dust cover for glass disc,rubber and Tygon tubing connections, 1 lb. each of whiterouge and castile soap, and detailed directions for use. For115 volts, 50 or 60 cycles, a.c.--_-_-_-_-___725.75

More detailed information sent upon requestVOOFQUALIT ARTHUR H. THOMAS COMPANY|LBORATO APPARAUSD

More and MoreLaboratories ~ O ~~ ~ ~ A

RtELY ON THOMAS P. O BOX 779 PHILADELPHIA 5, PA.Teletype Servicest Western Union WUX and Bell System TWX PH-72

UIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII

-KN

U

_ hlhlNllNl _Nlhlf !f

-0