'icon

This new single-deck model is asdramatic in improved efficiency asit is radically different in appear-ance from earlier Autotechnicons.

Boon to the busy laboratory . . .

processing or staining at will with-out annoyance of shifting beakers.

excellence in automatic tissue processing

Write today for Booklet 2-A, for descriptionof these new instruments.

THE TECHNICON COMPANYChauncey * New York

for better photomicrography

the DANPHOTphotom/crographic apparatus

Everything you expect from a really fine research instrumentyou will find in the Leitz PANPHOT photomicrographic unit-the most advanced optical and operational design ... lifetimeconstruction ... infinite versatility... top-flight performance.The PANPHOT, with a complete range of interchangeableLeitz accessories, permits photomicrography by incident ortransmitted light, either ordinary or polarized.* Instantaneous transition from filament to arc lamp

illumination* Camera reflex housing arranged for viewing from front

of unit

E. LEITZ, INC., Dept. SC-7468 Fourth Avenue, New York 16, N. Y.

__ I Please send me your brochure on the Leitz |PANPHOT. I

Name I

I Street

l City Zone- State I093555

K. LEITZ, INC.,468 FOURTH AVENUE, NEW YORK 16, N. Y.Distributors of the world-famous products of Ernst Leltz, Wetzlar, GermanyLENSES * CAMERAS * MICROSCOPES * BINOCULARS

SCIENCE is published weekly by the AAAS, 1515 Massachusetts Ave., NW, Washington 5, D. C. Entered at the Lancaster, Pa., Post Office as second classmatter under the act of 3 March 1879. Annual subscriptions: $7.50; foreign postage, $1; Canadian postage, 50¢.

U

29 JULY 1955 179

STEEL BASE*

POWERFUL INDUCTIONMOTOR

*SPINNING DRUM

*LOW PRICE, $76.00

Write for additional information or Free Catalog

Tambours, Stimulators, Time Markers, Power Supplies, Acces-sories available for 'Electric-'Ink' or 'Smoke' writing.

GLASS ABSORPTIONCELLS madeKLETTe

Makers of Complete Electrophoresus ApparatusSCIENTIFIC APPARATUS

Klett-Summerson Photoelectric Colorimeters-Colorimeters - Nephelometers- Fluorimeters-Bio-Colorimeters - Comparators - Glass Stand-ards-Klett Reagents.

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

SCIENCE, VOL. 122

RUGGED CONSTRUCTION

*"SIX" SPEED CHANGES

*SHAFT DIAMETER 5/8"

*PRECISION CUT GEARS

ROTARY WATERBATH SHAKER

* Variable speed '_____________.range 85 to285 osc. per min.

* Temperature range300C. to 100lC.

50*Available forshaking varioussize flasks.

A shaking apparatusthat is extremelyuseful for cultivat-ing microorganismsunder conditions ofaeration and withmore precise temper-ature control than ispossible in an incubator. It is particularly valuable inobtaining bacterial growth curves.

Detailed information available upon request

NEW BRUNSWICK SCIENTIFIC CO.v.BOX :s .NvE v - J.

P. 0. BOX sos * NEW lURN5WgcK. N. J.

180

The

SYNTHETIC MINIATURE

HU-MA-N SKELETON

Only 26 Inches Tall

Accurately ScaledIn Durable, WashableSynthetic Material

0

A Wooden CaseAnd Plastic Cover

Are Included0

Especially Adapted ForElementary Work WhereEconomy Is Important

No. ZK 500

Designed for use in elementary biology courses, theminiature skeleton has proved of value in psychology,health, safety, first aid, and physical education courses.The low price enables the smaller schools to have at leastone skeleton in the science department. The skeleton, withwooden case, weighs less than 20 pounds making it easyto carry from room to room.

The wooden case is constructed to permit the rotationof the skeleton within the case. An illustrated key cardon the door identifies the principal bones. This arrange-ment permits a student to study the guide and skeleton to-gether in order to more easily understand the skeleton. Ifdesired, the skeleton can be removed from the case andhung in a more convenient place. The hook on the skullprovides for attachment to other types of support.

Each skeleton includes an attractive wooden case,plastic skeleton cover, and an illustrated key card.

ZK500. MINIATURE SKELETON, Painted. The mus-cular origins are painted in blue, and the muscular inser-tions are in red on one side of the skeleton. Complete, withwooden case, plastic skeleton cover, and illustrated keycard. Each, $130.00ZK510. MINIATURE SKELETON. The skeleton is thesame as ZK500, but the muscular origins and insertionsare not painted. Many teachers prefer to paint the muscu-lar insertions and origins themselves, and the surfaces ofthese skeletons readily accept paint. Complete with at-tractive wooden case, illustrated key card, and plasticcover. Each, $115.00

Full, Life Size Skeletons available at $190.00

W. M. WELCH SCIENTIFIC COMPANYDIVISION OF W. M. WELCH MANUFACTURING COMPANY

ESTABLISHED 18801515 Sedgwick Street, Dept. E Chicago 10, Illinois, U. S. A.

Manufacturers of Scientific Instruments and Laboratory Apparatus

182 SCIENCE.VOL. 122-

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182 SCIENCE, VOL. 122