SCIENCENEW SERIES FRIDAY A SUBSCRIPTION, $6.00VoL. 97, No. 2526 FRDY MAY 28, 1943 SINGLE COPIES, .15

Accurate to 0.05 mg.

Convenient Operation

E. & A. Volumetric Glassware

New Three-Way Stopcocks

In this new Fisher Improved Deaminiz-ing Apparatus (another recent Fisher-E. & A. development), the absorption pi-

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mounted on a bakelite panel which is

oscillated by means of a rheostat-con-trolled motor, the speed of oscillation being variablebetween 0 and 240 per minute.

The absorption pipette is completely new in design,being isolated from the atmosphere by means of a re-

placeable rubber bag. The reaction chamber is ar-

ranged for convenient operation and the burette is

carefully calibrated. The apparatus permits analysis

with solution volumes up to 10 ml., with an accuracy

of 0.05 milligram.

All parts are made in Eimer and Amend's precisioninstrument and glassblowing shops. The entire sys-

tem is Pyrex glass, with special Fisher three-waystopcocks similar to those used in the modern UnitizedGas Analysis Apparatus.

Fisher Deaminizing Apparatus, complete, for operation on 110-v. A.C. or D.C. .......... $140.00

Micro Model Enables Analyses oF 1 ml. SamplesWhen samples of 1 to 2 ml. are to be analyzed, the Micro model of the Fisher Deaminizing Ap-

paratus should be employed. The Micro reaction chamber has a 12.5 ml. capacity evolution chamberand 1 ml. Ostwald type bulbs to permit accurate measurement of 1 or 2 ml. samples. The microburette is graduated from 0 to 3 ml. in 0.01 ml.divisions.

Micro model, Fisher Deaminizing Apparatus, for 110 volt A.C. or D.C. .$136.50.

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FISHER SCIENTIFIC CO. ElMER AND AMEND717 Forbes Street, Pittsburgh, Penna. 635 Greenwich Street, New York, N. Y.

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Entered as second-class matter July 18, 1923, at the Post Office at Lantcaster, Pa., under the Act of march 3, 18,9.

2 SCIENCE-ADVERTISEMENTS VOL. 97, No. 2526

Marshall-Laboratory Guide in Elemen.tary Bacteriology. 92 Experiments de-signed for a first course. 244 Pages,$1.75 (1941). By M. S. Marshall, Univ.of Calif.

Bremer-Textbook of Histology, 5th Ed.455 Illus., 36 in Colors, 580 Pages, $6.50(1936). By J. L. Bremer, Harvard Univ.

Lambert-Introduction and Guide to theStudy of Histology. 185 Illus., 542Pages, $5.00 (1938). By A. E. Lambert,State Univ. of Iowa

Stiles-Handbook of Microscopic Char-acteristics of Tissues and Organs, 2ndEd. Illustrated, 204 Pages, $1.50 (1943).By Karl A. Stiles, Coe College

Colin-Elements of Genetics47 Illus., 386 Pages, $3.00 (1941). ByE. C. Colin, Chicago Teachers College

Philadelphia

Neal & Rand-Chordate AnatomyWell organized for a semester, or two-quarter course. 378 Illus., 467 Pages,$3.50 (1939). By H. V. Neal, TuftsCol., and H. W. Rand, Harvard

Neal & Rand-Comparative AnatomyCorrelates and interprets the students'observations in the laboratory. 540Illus., 739 Pages, $4.75 (1936). By H.V. Neal and H. W. Rand

Davison-Mammalian Anatomy, 6th Ed.The standard text on anatomy of the cat.174 Illus., 328 Pages, $3.00 (1937). ByF. A. Stromsten, State Univ. of Iowa

Patten-Early Embryology of the Chick,3rd Ed. For beginning students in em-

bryology. 87 Illus., 228 Pages, $2.50(1929). By B. M. Patten, Univ. of Mich.

Patten-Embryology of the Pig, 2nd Ed.168 Illus., 327 Pages, $3.50 (1931). ByB. M. Patten, Univ. of Mich.

THE BLAKISTON COMPANY

GEOLOGICAL SCIENCESA Skull of Bison Latifrons from the

Pleistocene of NorthernCalifornia

By V. L. VanderhoofUniversity of California Publications

in Geological SciencesVol. 27, No. 1, Pp. 1-24,

Plates 1 and 2, 5 figures in textPaper 35 cents

ZOOLOGYDifferentiation and Growth of Gastrular

Anlagen Implanted Homoplasticallyinto Tadpoles of Hyla Regilla

By Morgan HarrisUniversity of California Publications

in ZoologyVol. 51, No. 2, pp. 41-86,

Plates 2-7, 2 figures in the textPaper 75 cents

UNIVERSITY OF CALIFORNIAPRESS

Berkeley Los Angeles

Address all communications to the Berkeley Office

LABORATORYDIAGNOSIS

OF PROTOZOANDISEASES

By CHARLES F. CRAIG, M.D., F.A.C.P.The Tulane University of Louisiana

Octavo, 349 pages, illustrated with 54engravings and 4 colored plates.,

Cloth, $4.50, net.

This work assembles in a single volumemany valuable procedures which have neveryet appeared in the texts on bacteriologyand parasitology. Here is included everymethod that has a real claim to value in thediagnosis of protozoan diseases.

LEA & FEBIGERWASHINGTON SQUARE PHILADELPHIA, PA.

VOL. 97, NO. 25262 SCIENCE-ADVERTISEMENTS

.N. U.N

Avidin1l e riConcetrats(FOR EXPERIMENTAL USE ONLY)

In view of the increasing interest in avidin and its laboratoryuse in biological and microbiological studies with biotin,Research Laboratories, S. M. A. Corporation, has respondedto numerous requests to make avidin concentrates available.

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SMACO Avidin Concentrates are dry, amorphous powdersprepared by fractionation of fresh hens' egg whites. The 'bio-tin-inactivating" potency has been standardized by micro-biological assay with crystalline biotin.1

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i. Eakin, R. E., Snell, E. E., and Wvilliams, R. J.: TheConcentration and Assay of Avidin, the Injury-Producing Protein in Raw Egg White, J. Biol.Chem. 140:535 (1941).

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4 SCIENCE-ADVERTISEMENTS VOL. 97, No. 252.

At ±/s50C Under Full LoadConditions

constancy of ±1/5 C. and a uniformityof--7/8' C. under full load conditions

characterizes the performance of the CastlePrecision Incubator No. 554. This- is far inexcess of the tolerance of ±-t 10 C., recom-mended by the American Public Health Asso-ciation.Accurate temperature measurements are pro-

vided with the use of a single thermometer.Because heat is' transmitted by interior radi-ation rather than by convection,. variationthroughout the chamber is minimized.Any heat lost by opening of the door is

quickly compensated for by the large heat re-serve provided by twenty-two gallons of ac-curately controlled warm water.The Model No. 554, illustrated, is recom-

mended for milk analysis by the agar platemethod. Other models in varying capacitiesfor various bacteriological applications are alsoavailable. Write-

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FOR the safe, economical, and efficient ap-plication of electric heat in the labora-

tory, Aminco Lobag Electric Heaters andControls are the logical choice because theyhave been giving dependable year-in andyear-out service in laboratories throughoutthe world for over ten years.

Whether for heating fluids, semi-fluids,solids, air or other gases, there is an AmincoElectric Heating Unit that will do the jobdependably and efficiently . . . and thereis a wide range of standard units of varioustypes and reliable, time-tested automaticcontrols from which to select, or, Amincoheating specialists can design and buildspecial units for almost any heating re-

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4 SCIENCE-ADVERTISEMENTS VOL. 97, No. 2526

MA 8 93SINEAVRIEET

The G&D pH AUTOMAT is available for prompt deliveryThe G&D pH Automatis a portable, completelyself-contained, battery-operated and direct read-ing meter for pH andMV measurements andfor all electrometric titra-tions. Its circuit, de-veloped by Drs. R. Gar-man (N.Y.U.) and M. E.Droz (N.Y.U.), incorpo-rates the latest achieve-ments of electronicdesign. The sturdyconstruction of the in-strument makes it wellsuited not only for usein laboratories but alsofor industrial controlwork.

Ask for descriptivepamphlet

GAMMA INSTRUMENT COMPANY, Inc. 95 Madison Avenue, New York, N. Y.

Zenker Fixed Tissues Reported RoutinelyHours from the Time the Fresh Tis

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MAY 28, 1943 SCIENCE-ADVERTISEMENTS 5

SCIENCE-ADVERTISEMENTS VOL. 97, No. 2526

403tiiY

U No. 20275-Disassembled

20270 20275

"SELAS" PORCELAIN FILTER CANDLESAmerican-made Selas micro porous porcelain filtercandles offer decided advantages over other typesfor work in bacteriological, pharmaceutical, andchemical fields. The filter portion, being all-por-celain, may be repeatedly cleaned by heating toincandescence or soaking in chemical cleaners with-out affecting life, porosity, or filtering character-istics. The practicability of ignition cleaning willbe readily appreciated by bacteriologists for theremoval of pyrogens.

Bacteriologists accustomed to the designations" coarse, " 'medium, ' and " fine " will find the

following table helpful in selecting the desiredporosity of Selas filter candles:

No. 10 porosity-Coarse preliminaryNo. 01 porosity-PreliminaryNo. 02 porosity-Intermediate bacteriologicalNo. 03 porosity-Fine bacteriological

The method of manufacturing Selas filter candlespermits control over the number of pores per unitof area as well as their sizes. As a result, unusu-ally rapid flow rates are characteristic of thesefilters.

20270-SELAS FILTER CANDLES. With permanent gl zed-on porcelain nipple for rubber hose connection. Theentire candle can be repeatedly heated to incandescence. Specify whether porosity 10, 01, 02, or 03 is desired.Size, inches. 5/8 X 3 5/8 X 5 5/8 x 7 1 x 71/1 1 X 91/4 11/2x 7% 11/2 x 91Filtering length, inches 2 4 6 6 8 6 8

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20275-SELAS FILTER CANDLES. With detachable metal connector. Combine the permanency and reliabilityof glazed-on porcelain head candles with the convenience and practicability of machined metal-head candles. Theremovable candle element can be repeatedly cleaned by ignition or washing. Sterilization may be accomplishedin autoclaves with the metal and rubber parts attached and ready for use. Because of the elastic joint betweenthe porcelain candle element and the metal connector, the differential-expansion cracks characteristic of cementedhead joints are avoided. Price includes rubber gaskets, knurled nut and washer for mantle connection, andwrench. Specify whether porosity 10, 01, 02, or 03 is desired.Candle size, inches.% 5/8 X 23/1a 5/XX43/a 56/8 6 3/16 1 X 83/16 11,4 x 61,4 12 x 81,4

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20277-SELAS FILTER CANDLES only. For replacement of the filter candle portion of No. 20275. Specifywhether porosity 10, 01, 02, or 03 is desired.Candle size, inches ........... 5A x 23/io 5/, x 43/1o % x 6./3o 1 x 63/1, 1 x 83/1o 11/2 x 61/4 11/2 x 81/4Each .1.00 1.00 1.10 1.75 1.75 4.50 5.00

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MAY 28, 1943 SCIENCE-ADVERTISEMENTS 7

The new ADAMS SLIDE BINDERS are an improved method forbinding 35 mm. transparencies of Kodachrome, black and white, orother film, between glass, in a cardboard frame bound with a gummedpaper wrap.

FEATUPRESSAFE-The film is protected from dust, fingermarks and scratch-ing by being placed between two pieces of glass. The glass whenmounted in the cardboard frame is practically breakproof. Bind-ing between the glass prevents the film from buckling.EFFICIENT-The film is automatically centered in the binder.All the equipment necessary is contained in the package deliveredto you, ready to use.FAST-Binding a set of slides should require only about a minuteper slide.THINNER AND LIGHTER-The glass used Is thinner (0.8 to 1.0mm.) and smaller (34 x 38 mm.) than the usual slides used andtherefore is lighter in weight-requires less space for storage.GLASS QUALITY-Only the highest grade, flat, non-corrosive glass,practically free of scratches, striae and bubbles is used. It is thesame quality glass used in making the well-known GOLD SEALMicroscope Slides.ECONOMICAL-Binding cost is low when compared with the costof all materials and labor required for other methods.UTILITY BOX-The box in which these Binders are delivered toyou is so constructed and of such a size that it will serve as anexcellent temporary storage box for two rows of completed 2x2"slides.A-1650 ADAMS SLIDE BINDERS for 100 2 x 2" (35 mm.)

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SCIENCE-ADVERTISEMENTS 7

. . _- -0 t__4 1-

MAY 28, 1943

8 SCIENCE-ADVERTISEMENTS VOL. 97, No. 2526

offff0When There's no Time

for WordsWartime calls for the simultaneous instruction of manystudents ... not a new job for B&L Balopticons whichfor years have been used for modern classroominstruction.B&L Balopticons are economical in teaching mate-

rial. One set of illustrations or specimens is madeavailable to a whole class at one time. There are models

for transparencies, slides, photographs or other opaque

objects or even actual specimens ... protecting large,brilliantly clear pictures which hold the attention ofthe entire class.

Here again the fine optical performance of anotherBausch & Lomb instrument, proved in peace, fits it fora vital wartime need.

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8 SCIENCE-ADVERTISEMENTS VOL. 97, No. 2526

SCIENCEVOL. 97 FRIDAY, MAY 28, 1943 No. 2526

Testing as a Part of Military Classification: BY THE Scientific Books:STAFF, PERSONNEL RESEARCH SECTION, CLASSIFICA- Objective Measurement: PROFESSOR ABRAHAM PE-TION AND REPLACEMENT BRANCH, THE ADJUTANT PINSKY. Pediatrics: DR. DANIEL C. DARROW. 488

GENERAL'SOFFICE ........47............3...... 473 Special Articles:The War Role of a Geological Survey: DR. ARTHUR Citric Acid Cycle; Sugar and Fat-Breakdown in

BEvAN ............................ ..............................................................478 Tissue Metabolism:DR.F. L . BREUSCH........490

Obituary: A Map of the Natural Amino Acids: DR. G. TOENNIES 492Isaac McKinney Lewis: DR. 0. B. WILLIAMS. Re-cent Deaths.480 Scientific Apparatus and Laboratory Methods:c nDet s ...................................................................................................... 4 0

I t - to D . JImprovement of Dew-Point Determination: DR. J.Scientific Events: A. VAN DEN AKKER and WILLMER A. WINK. Quiet-

Explorations and Field Work of the Smithsonian ing Paramecium for Class Study: PROFESSOR JOHNInstitution; The for Ab-B. .........4..................................................................................

stracts; The Transactions of the Royal Society ofSouth Australia; Rare Chemicals; The Mobilization Science News ............................ 10of Science; Presentation of the Charles FrederickChandler Medal ................................ 481

Scientific Notes and News ..................................483 SCIENCE: A Weekly Journal devoted to the Advance-ment of Science, edited by J. McKEEN CATTELL and pub-

Discussion: lished every Friday byIs. War the Progeny of Science, or Science theProgeny of War, or Are Both of these Suppositions THE SCIENCE PRESSFundamentally False? DR. ROBERT A. MILLIKAN. Lancaster, PennsylvaniaThe " Science Mobilization Bill": PROFESSOR JOHNQ. STEWART. Stairs in "American Men of Science": Annual Subscription, $6.00 Single Copies, 15 Cts.JAQUES CATTELL. Autobiography in a Democracy:

G.R.WIELAND ...................................................... 485 SCIENCEis theofficial organ of theAmericanAssocia-tion for the Advancement of Science. Information regard-ing membership in the Association may be secured fromvdQuotations: the office of the permanent secretary in the Snmlthsonian

Mobilizing Science. 488 Institution Building, Washington, D. C.

TESTING AS A PART OF MILITARY CLASSIFICATIONBY THE STAFF, PERSONNEL RESEARCH SECTION, CLASSIFICATION AND REPLACEMENT

BRANCH, THE ADJUTANT GENERAL'S OFFICE

GENERAL

THE construction of psychological tests for use inthe classification and assignment of Army personnelis a function of the Personnal Research Section of theClassification and Replacement Branch, The AdjutantGeneral's Office, War Department. The Classificationand Replacement Branch is responsible for developingprocedures for classifying and assigning all men in

the Army with the exception of those in the flightcrews of the Air Forces; it develops the policies andprepares the regulations which are used by classifica-tion officers in the field. An organizational and func-

tional chart (Fig. 1) of the Personnel Research Sec-tion accompanies this article.The two main objectives of classification are to con-

serve manpower and expedite training; -it is a processthrough which pertinent data concerning each enlisted

man are validly obtained and accurately recorded foruse as a basis in making the assignment in which hewill be of greatest value to the Service. Tests are

employed at every stage of the complex classificationprocess which continues throughout each man's mili-tary career. The personnel consultant and the classifi-cation and assignment officers in the induction sta-

tions, the reception centers and the replacementtraining centers of the Arms and Services, and inthe tactical units and posts administer tests as an

integral part of classification and assignment. Theprincipal divisions and stages of the personnel classifi-cation system are indicated in Fig. 2.Army needs dictate the types of tests in use. The

number of tests of all types used in the Army hassteadily increased since the initiation of the presentclassification system. Current tests and procedures