tACrIONAT1ONvRO8LEMS?here's help for you

HIS tireless servant in your laboratory will automaticallycollect any number (up to 200) of rigidly controlled samples

of predetermined fluid volumes. Each collected sample maycomprise any number of drops from one to four hundred. Aseach separate sampling is completed, the carriage automat-ically advances to repeat identical collections consecutivelyuntil the whole fractionation has been made.

All you have to do is to set it up for the' conditions of the'chosen experiment, short or long, and then leave it alone.The machine will plod along without attention hour after hour,all day (and night) long. When the job's done, it will shutitself off.

The Technicon Fraction Collector has been thoroughlytested in actual laboratory installations, where it has proveninvaluable to busy research staffs. We shall be happy to sendyou details.

Ref. Chromatography of Amino Acids on Starch Columns-W. H. Stein and S. Moore, Jrnl. Biol. Chem. 176, 337,(1948)

& saves time and labc;etves laboratory staffconsuming chore of fractioifor other duties.

& triples work output

:rof the fretful and time.n-cutting: releases workers

you can run it twenty-four hours a day, continuously,to triple fractionation output as compared with an 8hour laboratory day.

gives greater resolutionby collecting a large number of small fractions,frather then a few gross ones, you'll get more datafrom a given- fractionation, e.g. a chromatogram, ora fractional distillation.

assures accuracybecause the possibility of human error is automati-cally ruled out. Now fraction-collection becomes astraightforward mechanical procedure.

tidmicnautomatAcfractionollector

E EtI~ 1A49th OGRA CO21 5 lEast I 49th Street,N4ew York 5I1, N4.Y.

detailed Informatio tor

on the Iechnico Auto....... -

Nvm--...--------Addrs tate

city--------------------1

-

..............................

I t tells how you talk

p

The machine at the left is saying "Ah !"It's the new electrical vocal system de-veloped at Bell Laboratories. Top sketchshows human vocal system also saying"Ahh!" The electrical model is sketchedbelow it. Energy source at bottom of"tract" can emit a buzz sound, like vocalcord tone, or the hiss sound of a whisper.

No one else speaks exactlv like you.Each of us uses different tones to say thesame words. To study and measure how wemake speech, acoustic scientists of BellTelephone Laboratories built a model ofthe vocal system.

Electric waves copy those of the vocalcords, electric elements simulate the vocaltract, and, by adjustments, vowels and con-sonants are produced at pitches imitatinga man' s or woman s voice.

Using this electrical systeni, telephonescientists will be able the better to measurethe properties of people's voices. Knowingmore about speech they can find better andcheaper ways to transmit it.

This is another step in the research atBell Telephone Laboratories which pio-neered the exact knowledge of speech. Pastwork in the field is important in today's finetelephone service. Still deeper understand-ing is essential in planning for tomorrow.

BELL TELEPHONE LABORATORIESExploring and inventing, devising and perfecting, for continued improvements and economies in telephone serv icec

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I has the new

,',,,.,r,,, precision-perfected"PW RSTATVOLTAGE CONTROLSAuto-transformers of toroidal core design withmovable brush tap which rotates to deliver acontinuously adjustable output voltage fromAC power lines.The ideal all-purpose voltage controls, used inlaboratories throughout the country. With thePowerstat, you-.can be sure that the currentrating is the current available over the entirerange of output voltage. No need to refer to agraph to determine the allowable current ata specified value of output voltage.

6433-8 TRANSFORMER, Variable, "Powerstat"For use with "Glas-Col" Heaters or other electricalequipment. Transformer has an input rating of115 volts, 50/60 cycles, 1 phase; output voltagerange of 0-135 volts, maximum rated output cur-rent of 7.5 amperes available over entire range ofoutput voltages; maximum output of 1000 va. (7.5amperes at 135 volts). Suitable for all "Glas-Col"mantles up to and including the 50- $23 00liter size. ea

6433-9 TRANSFORMER, Variable, "Powerstat"-Transformer has an input rating of 230 volts, 50/60cycle, single phase and output voltagerange of 0-270 volts, 9 amperes, 2.4 $56m00kva. ea

"POWERSTAT" VOLT BOX-A compact port-able source of variable AC voltage, providing amuch-needed instrument for use in any laboratory.6433-10 "Powerstat" Volt Box, 115volts, 50/60 cycles 1 phase input; 0- $46moo135 volts, 7.5 amperes output. ea6433-11 "Powerstat" Volt Box, 230volts, 50/60 cycle, 1 phase line to $52.00deliver 0-270 volts, 3.0 amperes. ea moo

STANDARD recommends theuse of "Powerstat" voltagecontrols with "GLAS-COL"Heating Mantles . . . andSTANDARD stocks a com-plete line of "GLAS-COL"units.

SCIENCE, Vol. 114

m

mql r...

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* Scaling Unitsfor Every Typeof RadiationCounting

* Porta b I eCount RateMeters

* Health Mon-itoring Instru-ments for Person-nel Protection

* Gloss Wall,Mica Window,and WindowlessCounters

* completeLine of Acces-sories for theNuclear Labob-

~nuclearPRECISION IN-

STRUMENTATION

...WITHnuclear sCOUNT-O -MATICSCALING UNIT1 The scaler can be set to count auto-

matically a predetermined numberof counts and indicate, on an attachedelectrical timer, the time required toregister the preset number of counts.2 It is also possible, with Nuclear's2T-1 dual timer, to count for a pre-determined length of time, recordingthe number of counts.3 Model 163 can be manually oper3ated for application to many variedcounting requirements.A By simply switching the scaling4 factor to two, it is possible to usethe scaler as a monitoring instrument,listening to the clicks of the registeras an aural indication. It can be usedwith or without a probe.With these four distinct countingmethods, it is possible to utilize theversatile Model 163 Count-o-maticscaler to provide the most convenientmethod and technique for each specifictype of sample being analyzed.Before you purchase, get all the facts

about Nuclear products and services.

nuclear INSTRUMENT andCHEMICAL CORPORATION

237 West Erie Stree,A ChIcago 10, Ill.

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U SED to anesthetize smallanimals. This simple etherizerovercomes the disadvantagesof many older methods, andis sufficiently automatic to en-able surgical procedure withminimum attention.

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MANUFACTURERS * DISTRIBUTORS

SCIENCE, Vol. 114

J

4

spectrograpt

analysisI

WITHIN YOUR REACH!Rapid spectrographicanalysis is now placedwithin the economical

reach of alllaboratories

The CencoGRATING SPECTROGRAPH

with the new improvedWallace replica grating per-mits qualitative analysis andquantitative approximationsin any substance having lessthan 1% iron in its composi-tion. The wave-length rangeis 2800 to 7000 angstroms andthe dispersion, 16 angstromsper mm.

Write for descriptive pages1409-14.

CENTRAL SCIENTIFIC COMPANYScientific Instruments * Laboratory Supplies1700 Irving Park Road * Chicago 13, Illinois

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July 20, 1951 5

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Hegner&

Stiles

Gregory

College Zoology 6th Ed.Thoroughly revised and rewritten, this 6th edition of a well-known text has as its most notable feature 300 new illustra-tions. In revision Dr. Stiles has paid particular attention tothe sections of physiology and genetics, and in the chapteron the mammal the cat has been substituted for the rabbitas a type. Published in July-$6.00.

Evolution Emerging (2 vols.)From Science, April 20, 1951: "This is a story of Life inprocess of creation. It presents a marvelous pageant of ever-changing, living creatures ranging upward from the earliest,smallest, and simplest, and culminating in . . . the humanmammal. The pageant is presented not in words only butby use of a lavish profusion of remarkably fine illustrations.".Published in April-$20 the set.

Woodruff Foundations of Biology,& 7th Ed.

Baitsell -In this edition particular attention has been given to secur-ing new illustrations and revitalizing and redrawing most ofthe others. The textual material presents a logical, co-ordinated, and continuous story of biology. Longer chap-ters have been split into two parts. Published in June-$5.50.

Basic Horticulture, RevisedFeaturing in revision 9 pages of laboratory exercises, twonew chapters, and abundant illustrations, this up-to-datetext provides.practical information on the culture of fruits,vegetables, plants, and trees and shrubs in all parts of thecountry. Published in March-$4.75.

TH E MACMILLAN OMPANY

.0 £

July 20, 1951

Gardner

I

7

onCANCER

RESEARCH

New high intensity ultra-violet mono- -Ichromatic illumination with reflect-ing-refracting ultra-violet optics givestwice the resolving power attainable in thevisible portion of the spectrum. They, arecapable of disclosing differential absorptionof biological materials at high numerical aper-ture. The new Bausch & Lomb Grating Mono-chromator offers important advantages toexpand the scope of B&L U-V Optics . . . toopen new horizons in cancer microscopy:

* Linear dispersion _(Unobtainable with other types ofmonochromators)

* High aperture* Wide range

(With high intensity in the low U-V range)* Lower cost

WRITE for complete information and a demonstration to Bausch &Lomb Optical Co., 642-10 St. Paul St., Rochester 2, N. Y.

Bausch & Lomh 94d%9 MonochromatorSCIENCE, Vol. 114