NOW...

Multiple-point Speedo-max recorder at left is afamiliar sight in scientificlaboratories throughoutthe world. While the 6new instruments de-scribed below all appearto be practically identi-cal, each is different fromthe others.

See how these 6 new Speedomax recordersX2

SPEEDOMAX X-YRECORDER

Automatically plots the relationshipbetween any two variables whichcan be converted to d.c. signals.Both pen and chart motion are re-versible. Instrument records vacuumtube characteristics, hysteresis loops,stress-strain, temperature-elongation,differential thermal analysis curves. . . Applications are as broad as aresearcher's imagination. Write forFolder EM9-420(2).

SPEEDOMAX ADJUSTABLERANGE - ZERO RECORDER

Automatically plots voltage repre-senting force, weight, temperature,temperature-difference, speed ... orany other condition. SuppressingZERO pushes non-significant mv offscale. Adjusting RANGE spreadsfew significant mv right across chart.Range continuously adjustable from-0.1 to +1 mv .. . up to -2 to+20 mv; zero suppression, from-50 to +50 mv. Folder ND46(2).

SPEEDOMAX 2-PENRECORDER

Automatically plots 2 curves on 1chart simultaneously . . . overlappingor side-by-side. Follows minuteshifts in fast-changing variables withease. A "2-in-i" recorder, it takesany two standard Speedomaxranges. Circuits work with thermo-couples, Thermohms, strain gages,tachometers, thermal converters, pHcells . . . or most other primary ele-ments. Write for Folder EM9(1).

SPEEDOMAX pmt

6 precision electronic servantsto speed plotting of test data

A s the tempo and complexity of today'sresearch and engineering activities ac-

celerate, more and more investigators arestepping up efficiency through use of time-saving Speedomax recorders. Tireless auto-matic assistants, these electronic servants aretaking over the chores of routine computation... eliminating tedious manual plotting of data.

Especially timely are these 6 new Speedomaxrecorders developed specifically for laboratoryuse. While each is a specialist, it is also de-signed for a diversity of applications.

Common denominators for all six are tradi-tional Speedomax precision and high-speedresponse. Recording pens can whip acrossthe 93,4" chart in as little as 1 second, if the ap-

plication demands, though speeds of 2 and 3seconds full scale are also available. Balancingis velocity-damped to take advantage of thishigh speed.

Alert to the most minute variation in "X,"the sensitive electronic balancing system is theperfect complement for the instrument's ac-curate null-balance measuring circuit. Thor-ough filtering, shielding and guarding screenout transients . . . permit use of Speedomaxin the presence of severe stray fields.Net result: the investigator can follow com-

plex, fast-changing variables with ease andconfidence ... knowing that the record on hisSpeedomax is faithfully following the actualfunction being measured.

can solve your data-logging problems . ..

SPEEDOMAX PHOTOMULTIPLIERTUBE RECORDER

Automatically plots accurate record

of light intensity or other low level

radiation. Can be direct-connected

to photo-multiplier tubes . . . elim-

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able by switch are four ranges: 0.02,0.06, 0.2, and 0.6 ,us. Dark current

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EM9(1) to (3).

SPEEDOMAX POWERLEVEL RECORDER

Automatically plots radiation pat-terns of antennas and hydrophones. . . frequency characteristics offilters, amplifiers, loudspeakers, etc.Applies accurate "insertion loss"principle of measurement. Recordercan be supplied with full scale read-ing of 20, 30, 40, 50, or 60 db,referred to a base level of as littleas 0.02 microwatt. Write for FolderND46-51 (1).

SPEEDOMAX PRECISIONTHERMOMETER RECORDER

Automatically plots temperaturecurves for calorimetry, freezing andboiling points ... reads resistance ofplatinum thermometer to five sig-nificant figures. An "automaticMueller Bridge," it covers the entirerange from -260 to +500 C withprecision of ±0.01 C. Automaticrange-changing mechanism expandschart width 100 times. Write forFolder ND46-33-240(1).

Odum-Fundameutals of Ecology

This new book is a balanced synthesis of the entire field ofecology, with emphasis on group behavior and the interrelationsbetween plants, animals, microorganisms and man. It is designedfor two purposes-as a college text and as a reference forworkers in applied and related fields who desire a concise treat-ment of principles written without an overburden of technicallanguage.

The text is divided into three parts: I. Basic Principles and Con-cepts; 11. Major Environments; III. Applications.

The organization of Part I is entirely new and original with theauthor-both in regard to arrangement and the treatment ofprinciples. For each principle or concept there is a brief "State-ment', a full "Explanation", and one or more clear-cut"Examples". This semi-outline form saves unnecessary and con-fusing discussion and enables the student to concentrate onprinciples one-at-a-time, in logical order. Parts I and II are cross-referenced so that the reader or instructor may begin with theoryor the study of outdoor habitats. In Part III, the author presentsa synthesis of three main areas of emphasis-autoecology, popu-lation and community ecology and tropho-dynamic and ecosystemecology.

Illustrations have been carefully planned to achieve a balancebetween simplified, clearcut graphs, pictorial diagrams (manyof which have been especially prepared for this book) and story-telling photographs.

By EUGENE P. ODUM, Ph.D., University of Georgia, Athens, Georgia. About 340pages, 6" x 9", 120 illustrations. New-Ready in September.

W. B. SAUNDERS COMPANYWest Washington Square

New!

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Philadelphia 5

SCIENCE, Vol. 1182

The RecoELECTRIC

DESALTERFor the removal of inorganicsalts from organic and aminoacid solutions to be chromat-ographed.

The RecoCHROMATOCABFor two dimensional paperchromatography, using stand-ard filter paper sheets 183/4by 221/2 in., or smaller.

I

RACKS

Stainless steel or glass for onedimensional chromatography.

INDICATOR SPRAYSFor application of indicators to

I chromatograms.

t ) ~CLIPSAll stainless steel spring clips forholding chromatograms to glass rods

SOLVENT TROUGHSFor use in chromatocabs

, or one-dimensional racks.

I ALSO AVAILABLE:

I DensitometersI for quantitative deter-

minations on paperI Ultraviolet LampsI Pyrex Disc ChambersI Micro PipetsI Drying Ovens

GLUCURONOLACTONE, when fed to animals,prompts faster growth. Studles made withguinea pigs by MiUler et al.l, with chicks byAlmquist et al.2 and Reld8, and with rats byDeichmann et al.4, show that glucuronolac-tone increases rate of growth under con-trolled conditions.Glucuronolactone, added to diets deficient

in pantothenic acid, can also alleviate themanifestations of a pantothenic acid de-ficiency in rats, as reported by Hundleyand Ing5.Glucuronolactone is now available com-

mercially for your study and use. A bookletdescribing the product will be mailed atyour request.

REPORT AS A;ROWTH FACTOR

1. Miller. C. O., A. E. Siehrs, and F. G. Brasda.Glucuronic Acid as a Growth Factor in Guinea Pigs,Proc. Soc. Expt. Biol. & Med., 30, 636-38, 1932-33.

2. Almquist, H. J., E. L. R. Stokstad, E. Mecchi,and P. D. V. Manning, Identification of the Rice-Factor. The Carbohydrate Component. J. Biol.Chem. 134, 465-1940.3. Reid, M. E., Ascorbic and Glucuronic Acids as

Growth Factors in Chicks. Fed. Proc., 9, 368, 1950.4. Deichmann, W. B., J. J. Clemmer, and C.Downing, Glucuronic Acid Lactone, a Growth Fac-tor in Rats. Fed. Proc. 11, 1, March 1952.5. Hundley, J. M., and R. B. Ing, Prevention ofPantothenic Acid Deficiency with Glucuronolactoneand other Compounds Related to Ascorbic Acid.Fed. Proc. 12, 417-18, 1953.

SCIENCE, Vol. 118

A General Catalogueof the RECO Line ofPaper PartitionChromatographicEquipment Is

Available on Request.

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NEW! 30 POWER TELESCOPE

_0 <C t> Complete with Tripod Unessal Bargain PriesA beautifully made, sturdy, imported Instrument with doon ofuses. Spots 22ealiber bollt holes at 200 yds.. You em smthe erates on the moon-observe, close up, birds, aimals,

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SIMPLE LENS KITS! -Kits include plaini written, illms- Smort 1e 50fromE ..A.realbargan.0trated booklet showing how you can bulld lots of optical o. ,0-2.W $14.70 Ptd.Items. Use these lenses In experimental optics. building SAVE MONEY ON CUSTOM-MADE AND STOCKTemsCOP.:8, low power Microscopes, etc. - RETICLES AND IRIS DIAPHRAGMSStock # 2-W-10 lense ................... $ LOO Postpaid Tell ss yoor reqslromontsl Sced IluWrint for quotatlon on youir custom.Stoek -W-45 lenses ................... $ .00 PostpAd made NHeds. For steak Item ask for 3etl.l. Bulletin W or DiahragmStock #1O-W--0 lenses ................... $10.00 Postpaid Blletin W.IMPORTED POCKET MICROSCOPE EYE-PIECE MICROMETE11-lusportedli 190mm diameter. 10 mm. iscalsedivdeInto 100 parts. VaL. $5.00.

ADjUSTABLE? 20, 40, 60 POWER! Steek #30,035-W...... .............. $3.50 Pstp.A compact, handy precision instrument of STAGE MICROMETER-Importel Rectangular glass slide with photographl&

many uses. Select power you want, then focus sharply by turning special m scale-I mm. long divided lute units of 0.01 miL Val. to $10.00.focus ring. Good Quality optics. Full satisfaction guar- Stck *30,036-W ...................$4.00 Pstpd.

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SCIENCE, Vol. 118

GARCEAU ELECTROENCEPHALOGRAPHSA.C. Operated No Batteries

Inkless Writing Require no ShieldingShipped Ready to Run Prompt Delivery

THE JUNIOR GARCEAUELECTROENCEPHALOGRAPH

A simplified inexpensive instrument for recording electricalpotentials of the brain. Built-in interference eliminators per-mit use anywhere. Inkless records-no photography or fim.development required. Instantaneous localization with any2 of the 10 leads. Price $575.00 complete.All Garceau Electroencephalographs operate en-tirely from the 115 volts 50 or 60 cycle power lines.ELECTRO-MEDICAL LABORATORY, INC.SOUTH WOODSTOCK 2, VERMONT

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This all-new chart has been prepared from the standpoint of up-to-date placement ofatomic weights and atomic numbers in relation to the symbols and the elements. It iseasy to use, provides desired information at a glance, and is accurate. Information con-forms to recommendations of the American Chemical Society Committee on AtomicWeights and the Commission on Atomic Weights of the International Union of Pure andApplied Chemistry. Lithographed in dark blue and red on heavy plastic coated paper(washable). Metal bound top and bottom with eyelets for hanging.

No. Size 29" x 59'. Each space contains: Atomic symbol * Atomic number *1205 1 Name of element a Atomic weight or mass number. $AOO

Packed in heavy tube. Price, each. .a

No. Same as No. 12051 except that each space also contains: Electronic configuration1 205 3 . Natural occurring Isotopes (stable and unstable in the order of their abundance) *

Principal oxidation states * Valence electrons * Melting point * Boilingpoint * DensityPacked in heavy tube. Price, each ...... ... ...

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COMPLET No. For student notebooks. Same as No. 12051 but reduced to 8¼1/4 x I 1 " in block only;12052 punched for 3-ring binder. Back of chart gives list of common oxidation potentials

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THE SYNTHETICAL LABORATORIES

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8SCIENCE, Vol. 118

PHOTOVOLT Densitometerfor

CHROMATOGRAPHY

A photoelectric precision instrument forthe rapid and convenient evaluation ofstrips and sheets in filter paper chro-matography and paper electrophoresis

Write for Bulletin N 800 to

PHOTOVOLT CORP.95 Madison Ave. New York 16, N. Y.

AlsoColorimeters pH MetersFluorimeters Electronic PhotometersReflection Meters Multiplier Photometers

Interference FiltersJI

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KLETT MANUFACTURING CO.179 EAST 87TH STREETNEW YORK, N. Y.

.m|

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8 SCIENCE,, VOl. 118

The Portable, CompleteElectrophoresis Apparatus

Ir

Perkin-Elmer Tiselius Electropho-resis Apparatus at the UniversityHospital osf the New York Univer-sity -Bellevue Medical Center.

.Anl ordinary laboratory bench, without specialmountings, is sufficient for the installation of ThePerkin-Elmer Tiselius Electrophoresis Apparatus.Precision-ground, achromatic schlieren opticsyield sharp, clear patterns. Operating the instru-ment is so simple that highly trained personnelare not required a single technician can readilyoperate two units. Measuring only 63 inches inlenzth, the entire unit weighs 120 pounds and isconstructed of heavy aluminum. It operates forsex-eral hundred hours under its own powersystem.The apparatus is shipped complete and pre-

focussed with a 2 cc Tiselius cell 50 mm long,

Schematic cutaway of the newPerkin-Elmer Model 38 T'iseliusElectrophoresis Apparatus.

cell holder, ice bath and stirrer, silver-silverchloride electrodes, open-end 250 cc buffer bottles,stainless steel needles for filling the cell, groundglass screen for visual observation of the pattern,and a 3 '4" x 4 ,4" film holder. Double knife-edgeand diagonal slit for use with a cylindrical lensare also included.The dependability, accuracy and simplicity of

The Perkin-Elmer Tiselius Electrophoresis Ap-paratus have made it the choice of hospital andresearch laboratories throughout the world.

Wt'rite today for complete information.

ARMEO CAMS/t HACfIrCTROPIOSFS'S AIL! POSITIONING WITH GROMNO

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THE PERKIN-ELMER CORPORATIONNorwalk, Connecticut

Leading manufacturers of Infrared Spectrometers, Continuous Infrared Analyzer, UniversalMonochromator, Flame Photometer, Tiselius Electrophoresis Apparatus, D. C. Amplifiers, andother electro-optical instruments for analysis and research.

August 7, 1933 99

RADIOCHEMICALSC14 uniformly labeledL-Amino Acids andRibonucleic Acid Intermediates

immediately availableL-Arginine, L-Aspartic Acid, L-Glutamic Acid,L-Histidine, L-Lysine, L-Phenylalanine andL-Tyrosine uniformly labeled with C14 are

now available for the first time. Specific radio-activity for these amino acids is about 0.1millicurie per millimole. .

Also: C14-uniformly labeled ribonucleic acid,nucleotides, nucleosides, and other yeastderivatives, S35-labeled glutathione, aminoacids and intermediates.We shall be glad to discuss special ordersfor P32-labeled intermediates and otherradiochemicals by biosynthesis. SL2-1s

SCHWARZ LABORATORIES, INC.230 WASHINGTON STREET, MOUNT VERNON, NEW YORK

Just published . . .

ANNUAL REVIEW OF BIOCHEMISTRYVOLUME 22

Editor:J. M. Luck

Associate Editors:H. S. LoringG. Mackinney

Editorial Committee:H. J. AlmquistA. K. BallsH. J. Deuel, Jr.J. M. LuckH. A. Spoehr

Publisher:Annual Reviews, Inc.Stanford, California

Price:$6.00 plus shipping (15 cents-U. S. A. and Pan America;35 cents-elsewhere)

". . . should prove indispensable to all those who are interestedboth in the research and the teaching of biochemistry andnutrition."-Current Science, April, 1953.

CONTENTS: Prefatory Chapter, E. V. McCollum; Biological Oxidations, E. C.Slater; Proteolytic Enzymes, K. Linderstrom-Lang and K. Max M0ller; Non-oxidative and Nonproteolytic Enzymes: Glycosidases, S. Hestrin; Chemistry of theCarbohydrates, H. S. Isbell and H. L. Frush; Chemistry of the Lipids, T. P.Hilditch; Nucleic Acids, Purines, and Pyrimidines, G. B. Brown; CarbohydrateMetabolism, L. F. Leloir and C. E. Cardini; Lipid Metabolism, C. Artom;Metabolism of Amino Acids and Proteins, H. N. Christensen; The Chemistry ofCortisone, C. W. Shoppee; Nutrition, A. G. Hogan; The Chemistry of NeoplasticTissue, C. J. Kensler and M. L. Petermann; The Biochemistry of Teeth, H. M.Leicester; Immunopolysaccharides, J. Tomcsik; Chemistry of the Fungi, J. H.Birkinshaw; Ruminant Nutrition, C. F. Huffman; Photosynthesis, A. H. Brownand A. W. Frenkel; Biochemistry of Antibiotics, B. M. Duggar and V. L. Singleton;The Biochemistry of Vision, G. W. Wald; Fat-Soluble Vitamins, C. A. Baumann;Water-Soluble Vitamins, 0. A. Bessey, H. J. Lowe, and L. L. Salomon; Chemistryof Proteins, Peptides, and Amino Acids, Cl. Fromageot and M. Jutisz.

729 pages, including author and subject indexes 0 Cloth bound

ON SALE BY:ANNUAL REVIEWS, INC.,

STANFORD, CALIFORNIA, U.S.A.

SCIENCE, Vol. 118

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Finest Japanese Optics and WorkmanshipBuilt to our specifications. Priced farbelow comparable values. Be assured a Qof a lifetime of excellent performance.Equal to the World's finest optical in-strUment.LGreenough Type Stereo-Microscopes(Model UGA)Used by biological laboratory andstudents, mineralogical labs, andfactories. Excellent for dissectingand mineralogical work.Includes three paired wide-angleeyepieces: 5X, lOX, 15X.Three objectives: 2X, 4X, lOX.Magnification: lOX to 150X. _Wt. in carrying case: 11 lbs.

$225.00Binocular Microscope (Model E 3 N)Used by research laboratory, re-search technicians, physicians and

scientists. Instrument complete forvisual and photomicrography.Includes Monocular tube for photo-cmirographyCalibrated mechanical stage3-Lens NA 1.4 CondenserCalibrated ABBE DECENTERING

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Four nosepieces: Achromatic, 5X,lOX, 40X, 10OX. Coated.

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SHAKER-INCUBATORFor metabolic studies such as aw

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Protein coagulationApplications requiring shaking at

constant temperatureTemperature range: 250 to 1000 C.Flask temperature controlled within ±0.01 50 C.Shaking speeds: 40, 90 or 125 cycles per minuteStainless steel racks are available: (1 ) for holding

up to thirty 20-mi. beakers or 25-mI. Erlen-meyer flasks; (2) for holding up to twenty 50-ml. Erlenmeyer flasks.

1. Racks move on Oilite bearings-smooth and quiet operation-long life.2. Separate ice compartment-no ice in bath liquid to prevent full travel of shaking rack. This allows con-

tents of the vessels to be kept cool during preparation of reaction mixtures, and replacement of airin the gas phase.

3. Clips hold solution vessels firmly in place to prevent them from floating in the bath liquid.4. Boiling temperature reached within 15 minutes.5. Either one gas may be used, or -two gases simultaneously.6. All beakers and flasks may be simultaneously cooled, gas equilibrated, incubated or boiled.7. Since the air space under the gable cover is kept saturated by the water of the bath, evaporation losses

from the solution in the flasks are negligible, and readjustment of volume at the end of the experi-ment is obviated.

8. Two gas flowmeters are supplied-easily and quickly mounted or removed.9. Level of bath liquid is maintained automatically.

10. Compact and light in weight-readily portable.BULLETIN 2239-K

FREEZE-DRY APPARATUSDesign based on the work of outstanding

authorities in the field of freeze-drying1. Compact and mobile.

L M ^ r - S> 2. Constitutes a complete freeze-dry laboratory.3. Suitable for various methods of freeze-drying.4. Equal drying rate on all openings.5. Large drying capacity-5.56 pounds of water vapor con-

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6. Can be operated with mechanical refrigeration alone, withmechanical refrigeration in conjunction with dry ice, orwith dry ice alone.

--1; B w _ 7. Contanmination avoided by the use of non-corrosive materialsin its construction.

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easy servicing and maintenance.BULLETIN 2240-K

AMERICAN INSTRUMENT COMPANY, INC.Silver Spring, Maryland * In Metropolitan Washington, D. C.

August 7, 1953 11

NATURAL

MICRO-VISION

with the finestoptical system ever producedfor wide field work

You want distortion-free magnificationof the object ... you want the image to beclear and sharp, in vivid stereoscopic re-

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* Full critical coverage of widerfields than ever before* Dustproof prisms and nose-piece, protected for the lifetimeof the instrument* Shockproof construction, foryear after year of hard,on-the-job use.

WRITE for informative 24-page cat-alog, and for a practical demonstra-tion. Bausch & Lomb Optical Co.,64243 St. Paul St., Rochester 2, N. Y.

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BAUSCH LlOMB CENTENNIAL

1CIENCE2 Vol. 118

I I a

12