THIS NEW

cenCO®-PintoSURFACE COOLERwill double theusefulness of your

Waring Blendor

This new device is designed to prevent thevaporization and splashing of liquids in aWaring Blendor, stabilizing the agitatedliquid at its surface where cooling is mosteffoctive. Temperature of the liquid will bemaintained at 1 to 20C. above the temperatureof the circulating water. This reduces or elim-inates vaporization of the solvent It has beenfound excellent for rapid copra analysis. Thecooler bulb conforms to the shape of the con-tainer, leaving just enough clearance to pre-vent particles from becoming entrapped. Itwill fit any standard Waring Blendor containerof about 1000 ml capacity; bulb displacementone-half immersed is approximately 100 ml.

No. AD 17249 Cenco-Pinto Surface Cooler,without support stand, each. $19.00No. AD 17227 Waring Blendor, Two SpeedModel PB-5, with "Pyrex" brand glass con-tainer of 1000 ml capacity, bakelite coverand stainless steel cutting blade assembly,for use on 1 15 volts, 25 to 60 cycles, ACor DC .$44.50Other models from $33.20 to $46.20 in-duding Federal excise tax.

Write for Bulletin AD86 containing full detailsabout Waring Blendors, the Cenco-Pinto Sur-face Cooler, and accessories.

THE NEW

ceaco -PintoBLADEASSEMI LY

Designed for use withmaterials likely to dullstandard blades such ascopra. Made of specialspring steel with threeblades providing sixcutting edges.

No. AD17248 Cenco-Pinto Blade Assembly,fits standard WaringBlendor containers of1000 ml capacity,each. $7.00

am dep.doe sourc@ orsupp 1t ovt hIng youw need inidSMe MsIrws,si and labo-stry swOpplbs. Ov20,000Roms... 14 brech offices and were-hues..

CENTRAL SCIENTIFIC COMPANY1700 IRVING PARK ROAD 0 CHICAGO 13, ILLINOISCHICAGO NEWARK BOSTON WASHINGTON DETROIT SAN FRANCISCOSANTA CLARA LOS ANGELES TORONTO MONTREAL VANCOUVER OTTAWA

REFINERY SSUPPLY COMPANY62 I EAST FOURTH STREET* TULSA 3, OKLAHOMA2215MSKINNET AVENUE 0 HOUSTON 3,TEXAS

April 2, 1954 1A

What General Electric People Are Saying...

W. H. ROBINSON, JR.Mr. Robinson is Manager of Advertising, LampDivision

A "hairpin in a bottle," the first incandes-cent lamp made practical by Edison in 1879,began a chain of circumstances that broughtour country and our way of life out of one worldand into another.For the principal difference between the Amer-

ica of today and that of 75 years ago is elec-tricity-the energy, and the appliances andequipment that help the factory worker, thefarmer, the homemaker-that relieve us ofdrudgery and make each hour of working timefar more productive.When Edison turned his inventive, but very

practical, mind to the problem of electric light,he realized that it would not be enough merelyto invent an efficient light source. There hadbeen other incandescent lamps in the past, someof them quite satisfactory in the laboratory-but all suffered from inherent defects that pre-vented their widespread use.The job, as Edison saw it, was to perfect a

lamp with long burning life, that could bemanufactured in large quantities and offered atlow cost. Large numbers of these lamps wouldhave to be supplied with electric current from asingle source-yet it must be possible to turnlamps on and off individually.Thus Edison had to solve not only the dif-

ficulties that had balked other inventors. Healso had to devise a method for satisfactorysupply of current, which would have to bemanufactured and brought to each lamp, readyfor use at the customer's wish.

In other words, Edison conceived and created,in miniature, the entire electrical industry aswe know it today. He could buy very little.Generators, wiring, sockets, switches-all hadto be invented, designed, manufactured.The "hairpin in a bottle" that burned for 40

hours in EJison's laboratory in 1879 was farmore than a better light than the world hadyet known. It was also the starting point forthe electric utility industry, the electricalmanufacturing, and the electrical constructionindustries, that make it possible for electricityto serve us today.

at The Electric League,Chattanooga, Tenn.

R. M. SWETLANDMr. Swetland is Manager, Illuminating EngineeringLaboratory, Lighting and Rectifier DepartmentIt . . Approximately 40,000 traffic fatalitieshave occurred on American roadways during1953! About 60% of these-roughly 24,000-occurred at night. Experience, over many years,proves that fully one half of these night fatali-ties-some 12,000 lives-could have been savedby adequate roadway lighting-protective visi-bility!The National Safety Council estimates the

total economic loss, per traffic fatality, as

$95,000. Thus 12,000 fatalities represent over1.1 billions of dollars in such losses.The American public now spends approxi-

mately $1.25 annually per capita for streetlighting. It is reliably estimated that the dou-bling of this investment in protective streetlighting (another $200,000,000) would elimi-nate this 1.1 billion in economic loss; that is,each $1 additional investment in roadway light-ing saves over $5 in economic loss plus its sharein saving some 12,000 American lives.Higher illumination levels will be needed to

adequately protect future traffic flow-bothvehicular and pedestrian. Luminaires giving in-

creased light output, properly controlled, are

being planned to meet these demands.Systematically planned street lighting im-

provement programs pay attractive dividendsin (a) merited illumination and protection foreach type of roadway, (b) standardization ofequipment, and (c) a maximum of protective,visibility per $1 of investment.A recent reliable poll of experienced street

lighting engineers reveals that only about 7%of our lighted streets and highways now meetA.S.A. recommended illumination levels.Thus, we're a long way from the street light-

ing saturation point.at YalE University

e4F?7///yo7 ow/7azde Yn_

GENER,AL* ELE,C,TRIC

SCIENCE, Vol. 1192-A

A0,chrom,.andP tselecti oP

apparatusand equipment

Keeping pace with the growing use ofchromatographic analysis as an impor-tant research tool, Schaar and Companyis ready to serve you with a completerange of the finest equipment and acces-sories used in the chromatographicmethod. We are proud to present thiscatalog to you, and feel sure it willprove an invaluable aid.

FOR YOUR COPY WRITE FOR CATALOG AC-54

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Free detailed literature and specifications upon request

CARL ZE I SS, IN C., 485FifthAvenue, NewYork 17, N. Y.Guaranteed uninterrupted repair service

April 2, 1954

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Vitamin Free Test Casein Vitamin SuppleVitamin Free Caseincsal

HydrolysateHoAmino Acids & Peptides

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Bacteriological Media & IngredientsAdenylates, Nucleates, Purines & PyrimidinesComplete Animal Test Diets & IngredientspH Indicators Reagents & Stains

ements

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icals

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SCIENCE, Vol. 119

OmClinical pH Meter Mod. 125-B for

Blood pH Tests

7N~fLN

High accuracy, combined with simplicity ofoperation and maintenance. $165.-

Write for Bulletins Nos. 118 and 122 to:

PHOTOVOLT CORP.95 Madison Ave. New York 16, N. Y.Also: Densitometers for Paper Electrophoresis * ClinicalColorimeters - Fluorimeters * Hemoglobinometers * Ex-posure Photometers for Photomicrography * Fluorescence

Comparators for Diagnex Test * Interference Filters

as:

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I A REALLY EASY-TO-USEGAS FLOW COUNTERwithmaximum efficiency for carbon14 and other soft betasModel D47 permits extremely sensitivegas flow techniques . . automaticallycounts as many as 50 solid or liquid ra-

dioactive samples with C-110 samplechanger . . automatically scans paperradiochromatograms with C-100 "Acti-graph". . allows manual counting withshielded mount. Model D47 featureswindowless or thin window (150 micro-grams,"cm2) counting in both the geigeror proportional regions . . is the mostversatile gas flow counter ever produced.

. . ideal for tritium, carbon 14, sulfur35, etc.

. . detects all soft or hard ionizingradiations

. . converts from windowless to thinwindow in.seconds

. permits both geiger or proportionalcounting

. . bubbler and valve adjustments com-pletely eliminated

* . extremely low background* . now in production

Write for the complete details on thenew Model D47 gas flow counter.

Nuclear Instrument and Chemical Corporation237 West Erie Street, Chicago 10, Illinois

CHICAGONEW YORKLOS ANGELESDALLASHOUSTONSILVER SPRING, MD.

April 2, 1954 7A

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REMEMBER

5Zl7e id. n. iZatlelI ffeani Qua/ki yif there is an aminiiio acid-:- in vour future

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NEW NEW propyl homologue ofmnethionine)

PRODUCTS {and more than 100 otherslisted among the recesatadditions to our

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MSE "MAJOR" CENTRIFUGE3.6 liter capacity

This centrifuge has everything-large capacity, speeds up to

6,000 r.p.m., a wide range of interchangeable swing-out, angleand basket type heads, a dual capacity super-speed unit and a

variety of buckets, adaptors and carriers. It is the finest heavyduty general purpose centrifuge available today. Ask for MSEBulletin No. 125.

Left: The entire front of the "Major"hinges down for easy access to the elec-trical instnalntion.

Manufacturers: CANADIAN MSE LfMITED of Toronto 18, Canada & MSE LTD., of London, England

f J. BEEBER CO. INC., 838 Broadway, New York 3, N. Y.

Distributors: and 1109 Walnut St., Philadelphia 7, Pa.TECHNICAL INSTRUMENT CO., 122 Golden Gate Avenue, San Francisco 2

SCIENCE, Vol. 119

SAFER AT HIGH SPEEDS ...

' ERVAL OMNI-MIXER

Here's an all-purpooe high opeed mixer designed especially for utmostefficiency and protection for the laboratory worker. Proven superior Inlaboratories across the nation indiapensable in lab proceduresinvolving emuiloifying, homogenizing, mixing and diointegrating organ-sms, liqXidsand a wide range of other materialo.Servall Omni-Mlixer will hold ordinary, Inexpensive glass jars withcomplete safety against oplashing, dripping or spraying. Infectious ortoxic materials can be loaded into the opecially designed stainless steelchambers and sealed before being attached toD mixer.

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MARCH -1954- CATALOGUEsenid for your copy

H. M. CHEMICAL COMPANY, LTD.1651 - 18th St. Santa Monica, California

BOOTH 36Fed. of America

Society forExperimental

BiologyConventionApril 12-16

Atlantic City

IN=

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A tough, flexible, paraffinic thermoplastic oftranslucent white appearance with wax-like surfacewhich can be marked with the usual glass markingpencil. Lightweight (specific gravity 0.92), and un-breakable in normal use. Highly resistant to chemi-cal attack.

Polyethylene, of high molecular weight, is usedin laboratory ware and has a softening range ofapproximately 108° to 1110 C. Since both strengthand chemical resistance are decreased at elevatedtemperatures, articles of this material are used mostsatisfactorily at temperatures below 550 C and arenot recommended for use above 700 C.

Polyethylene is suitable for use at room tem-peratures in contact with liquids such as distilledwater, mercury, buffer solutions, concentrated

alkali, concentrated hydrofluoric, phosphoric, hy-drochloric and acetic acids, sulfuric acid to 60%,chromic acid to 40%, dilute nitric acid, fluoboricacid to 45%, formic acid to 90%, formaldehyde to36%, hydrogen peroxide, ethylene glycol and glyc-erine. Prolonged storage in polyethylene bottles ofcertain volatile reagents such as acetone, ether,toluene, etc., is not recommended because of theirrelatively high rate of permeation through the walls.This limitation does not affect the use of suchmaterials in open polyethylene vessels such asbeakers, funnels, etc., although some of thesereagents may cause slight swelling of the plastic.

Polyethylene ware should not be used withbromine, carbon bisulfide or concentrated nitricacid.

Copy of Bulletin 114, listing complete assortment now available, sent upon request.

aOFQUALIT

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WEST WASHINGTON SQUARE PHILADELPHIA 5, PA.Teletype Services: Western Union WUX and Bell System PH-72

April 2, 1954 I9A

* 1,2-Diaminoanthra-quinone

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* 1,2-Diaminoonthra-quinonesulfonic Acid* a-y-DiaminobutyricAcid

* 2,2'-Diaminodiphenyli* 3,3'-Diaminodiphenyli* 4,4-Diaminodiphenyl-

amine* a-y-DiaminoglutaricAcid

* 2,4-Diamino-6-hydroxy-pyrimidine sulfate

* 3,5-Diaminopyridine* a-t3-DiaminosuccinicAcid

* 1,1'-Dianthrimide

DA

* Dibenzopenthiophene* Dibenzoyl-l-arginine* Dibromoanthracene* 1,2-Dibromohydrin* 1,3-Dibromohydrin* 2,6-Dibromopyridine* Dibromosuccinic Acid* Di-tert-butyl Ketone* 1,5-Dichloroanthra-quinone

* 4,4-Dichlorobiphenyl* Di-(2-chloroethyl)-methylamineHydrochloride

* 5,7-Dichloro-8-hy-droxyquinaldine

* 5,7-Dichloro-8-hydroxyquinoline

* 2,6-Dichloropyridine* 6,7-Dichlororiboflavin

(Anti-riboflavin)* Didymium ChlorideAsk for our newcomplete catalogue

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IOA SCIENCE, Vol. 119

JUST PUBLISHED!

A volumecontaining the 461 Pages,6x 9,papers of 33

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mechanism laboratory diagnosismechanisms of immunity ecology and pathogenesis

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Many new and interesting items are included in themore than 10,000 listings in this handsome new

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SCIENCE, Vol. 119

ANk Am-

12A