ACID DIGESTION BOMBNew fromPARR

Provides a rapid and safemnethod for dissolvingglass, silicates, nitrides,rocks and other refrac-tory materials in HF,HC1 and other strongmineral acids at tem-peratures to 1 500 C. andpressures to 1200 psig.Acids do not attack thisbomb and complete re-covery is assured, includ-ing any trace elements.

The acid charge is held in a 25 ml.thick walled Teflon* cup within asturdy metal bomb. The cup can beremoved for convenient samnplerecovery and easy washing. Nowrenches or clamps are needed toproduce a tight seal.*duPont TFE flurocarbon resin

Write for Data Sheet 4745 Cross-Section Diagram

m Ill1Ai

Circle No. 101 on Readers' Service Card

Unique TSI® (Time Sterile Indicator) Tapes and Labelsare chemically impregnated to produce the words"STERILE" when exposed to the proper levels of heat.A complete line of TSI tapes and labels are available foruse in standard and high vacuum autoclaves as well as

high temperature ovens. Alsoavailable are Time Thermal Tapesfor use in temperature ranges of-196°C to +550°F. All tapes arepressure-sensitive, stick quicklyand remove cleanly. EconomicalTime TSI tapes and labels in-crease Lab efficiency.FREE BROCHURE!Write for samples, illustrated bro-

h; *chure, and the name of a dealer nearyou!

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Circle No. 103 on Readers' Service Cardl -t -I II o i I LLL LLLllll- w - -T r ---T =~ T+IHIf4, t--- C Tf

44-

01ZlSW t lt

... LI I 11 ..t-.t t+. A thtt+>*t

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Low Temperature Difference Spectrum (A) and low tem-perature Derivative Spectrum (B) of electron transportmembranes (1 mg of particle protein per ml) isolated fromthe chemoautotrophic microorganism Nitrobacter,-iwino radskyi.Courtesy of L. A. Kiesow, Naval IViedlical Itesearch Institute,Bethesda, Md.

Accessories available include: Rapid Mixing Chamber/Fluo-rescence Attachment/Oxygen Monitor/Anaerobic Cell/RapidStirrer/l x 2 cm Cell Block and Chromatographic Scanner.

THE MULTIPLE ADVANTAGES OFLOW TEMPERATURE ANDDERIVATIVE SPECTROSCOPYWith the Aminco-Chance -Dual Wavelength/Split BeamRecording SpectrophotometerThe low temperature (liquid N2) attachment enables the researcher to obtain an

increase in sensitivity while using small volumes and low concentrations. There is aconcomitant increase in resolution through the sharpening of existing peaks andshoulders, and the exposure of peaks completely hidden at ambient temperature.

One of the modes of operation inherent in the Aminco-Chance Dual Wave.length/ Split Beam Recording Spectrophotometer is to record the derivative of anabsoiption spectrum. The method offers increased resolution. Since only a singlesample is utilized the errors which normally occur because of non-homogeneitybetween the sample and reference are eliminated.

A combination of the two methods offers the results shown in the curves at left.This instrument can also be operated as either a dual-wavelength or a split-bearn

spectrophotometer by simple adjustment of three controls. In the dual-wavelengthmode, it can detect small transmittance changes superimposed on a highly absorbing,turbid sample. In the split-beam mode, it is able to record the spectra of highlyabsorbing, turbid materials.

For complete technical details write for Bulletin 2383.

Celebrating Our 50th Year of Service to Science and Industry4N AMERICAN INSTRUMENT CO., INC.

8030 Georgia Avenue, Silver Spring, Maryland 20910 U.S.A.

X. nanrxneters LAN

23 JANUARY 1970 397Circle No. 54 on Readers' Service Card

New ultravioletlaser spurs studiesin fluorescence,scattering andluminescenceAvailability of the first practical ultra-violet laser, Spectra-Physics Helium-Cadmium Model 185, has openedmany nev., possibilities in chemicalresearch.

For example:* The laser's 15 mW output at 3250 Asignificantly increases scattering andfluorescence effects in almost all or-ganic matter and in many inorganicmaterials and solutions. For scatter-ing the 185 is up to 14 times moreefficient than other lasers.* The focused UV beam can be usedto irradiate cells or parts of cells . . .

perhaps even individual chromo-somes.* Also, new studies are made pos-sible based on the 3.81 eV photonenergy of the 3250 A line, which isgreater than the covalent bond energyof NH (3.8 e\V) and CH (3.47 eV).

Spectra-Physics Model 185 Helium-Cadmium Laser makes many otherapplications possible and practical.It's available now. For complete in-formation, send the coupon below.--I---n----------

I am interested in the ultraviolet laser.Please: Send descriptive literature.

Have local field engineer contact me.

Name ..........................................

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u Spectra-PhysicsSpectra-Physics, 1250 West MiddlefieldRoad, Mountain View, California 94040.Phone: (415) 961-2550

Circle No, 80 on- Reciders' Service Ccar

MEETINGS

Nortl isAmlericanl l'Kla'leotoilo)gicalC(ivelntion

ale.wcontolotI de'.1is ws ith dead 01rit-tuISis.S, huLit it i.s lr I0om heint.j a dIC'teadsciciice. 1-1clhei clilncss ot tle pi otessionlw\ as demontliistratted at the Nor-thi Amaelni-can1 I'.leo)i tolo iaIl (Io envc t ionI, 5-7iSeptetilher 1 9(i9 iIn (h}iclto. 1 Ier-e areestinmated to hie .tbout 500) paleoitol-ouists inl thIs, lhcm isphelt1e-: miior c tII.olne-thil-il of thecm., attended thecse meect-ilme. to eatll 8)p0tplelprs ;nd to exc\hCel;lcinltllnltiol ielic-cctls \ th tlhil- Col-

1 he con l\ieto(n5 hel il aIt thec FielduseiCttLII ot N,ttitL ,ll listot it \V,ls a

joinit eCtnlt of tilie PalconI t oklo-ICaelSociety , Societv(of -Ceonomllic P.dleontol-olti.Asts 0tlldNil.InIlc-its, SoiCctv 01

Ver tchirtc Patlletoloe°ists. Paileohot tll-

ictel Scctioull 01 the B(tloiiii.il S<;iicet\ol mimlcie'. -nd Amcitem A\ssoetCtiOtlo 1Stritiegr.tphic Pals\n ol10 iists. This W.1sthe fit st prol-ofessit- i\de ineeting, to hehld1 in ll ,leastcin.decides

1 lie snLhjet ma1.ttter otf ptlcontolog'y(\e ILlaps tliC dliseipliti;,- 11oin-1ltrLIiCs Ot1.othI 1hiolos1* lid ite(,,|h.t 1.eel1in1i(ttincouce:lts 1iid LLtt,t sw ith cach. Howlos c cr,55 tli hiolois thstloier tossard the ilolec-uhir lesel mild eeoloes! tos\ard ceophiss-iCs, the paleonltolog_ist tt ti.ttIoiald iiiect-nes i liecen ill th'e, position of themanl ticd betwscs ltiw5 Rotilmail Cchariots:lie tiivs iiot lie tot ii to bits, hnit liecertmilils' e'elS uLi010tothtable t1l-roii tiliiito ililic.

I- sVC1t thoim,ih die studelIts Of fossilsosc 1to lect aIpart il oili tlicii- allited

scieltists. thcy still recc)lizmii theiral1leiatinces lIy be-intiniii vsith a cotil-v eI ttii510\- i C Sympsi itl l concernedsith vari otis philosophies of correl.mtiollot rocls bv their ciclosedi fossils (or->.l-iiiedl liv R. H. Tedilor-cd AniericanNI LSCeiIll of NtnIral H istory) andclosted WAith at comparable;C Sy'mllpOSiLlullinquilring ilito the eoltition of the ma-

jor liioloeic categorics. flio e,-Arly 1lga1eto the vertelirates (Nicholas Hottot III.NAttioi NIlNnsCeIll of NaLlral Histor ).

lie totie for this ash sessioni v as set,ilt paltlt, hi the lianqlICt address ofPhililp AbeClSo11 ( C artiegC(ie IlnstittitiO OtfN\Wish ilietoll, GCcophsical l aliorahtr y

Oil CeVolItiotil01) irotCinsTleI-eCiertiti l sLihjeCt ot irecs 5\as

discussed, aiid mew titer piretatis ss CrCdlensi\C( thfclio .loiii the Standpoitit ofthe o rgaiiisnims that help to build reels(Notimi1). Ness%vcl, Americ:it MInLSC-

. .. offers an overall light gain of 106 with atypical background of 1010 lumens/cm2.(light equivalent input.)Typical operating voltage for these conditionsis 40'%V The background indicated is for atube having bialkali photocathodes,-tubesare also available with a range of S-20 cath-odes for use out to 8,000 Angstroms. Inputand output windows are flat Zinc crown glass,50 mm diameter. Type 9693 is available withsapphire input window for use in the UV.Developmental types are now being made withfibre optic windows. All present types arefurnished with P-11 phosphors throughoutalthough other types of phosphors are underinvestigation O Tubes are normally suppliedpotted in silicon rubber and a number ofvariations are available. A complete package,including electromagnet, divider chain, highvoltage power supply and magnet supply isoffered. A permanent magnet is also avail-able OI An extensive technical manual, aswell as useful application notes, are availableon request. Write on your company letter-head to:

GENCOM DIVISIONvarian/EM I

T N 7 o Reccier Srvie Cord

Circle No. 77 ot) Reciciers' Service Corcl

LIu of Nittlrall History) and chanigesin the reef comtmunity through time (J.Keith Rigby, Brigham Young Univer-sity). The general topic of overall com-munity evoltution was also conisidered(Leigh Van Valen, University of Chi-cago).

In the past decade, thc StUdy of nan-noplaniktoni has undergone an explosivedevelopmenit, comparable to that ofthe Foramiinifera in the 1 920's whenthese organismis caime to be recognizedas economically important. This grow-ing field was sUrveycd in one srm-posiuLm on the org.nlic-xWailled formis(A. R. Loeblich. Jr.. Chevron Oil FieldResearch Comipany) and in another onthe calcareoLus aInd siliceouLs organMisms(Helen N. Tappan, University of Calli-fornia at l os Angeles). Larger orga-nlismlls and a moreg1eochemicall ap-

proach were evident in a sessioni Onlphosph.ate in lfossils (Chairles \V. Collin-soni, lllinoios Geological SLIIV C\V)As coUld he pr-edictedt a va.irietv of

iew points ptvere espouSed.1 in a1 Sx mpo-siuLmII onl the genluLs cOncCpt (1Thomnas \W.nmsisden. Oklahomia GCologica1l SLIu\!\)

each speaker- being1 illilienCiced by thepecCUliarities of the org1nisms hestudiCCd. Sinillar disagreement character-ized a session on teaching of paleon-tology (Rober-t M. Linslev, Colgate Uni-versity) xshich hcad bCCee a1ccUIrately suLb-titled as a niethodological inqLtiry inltothe eschecwal oftpclantical pedal.gogi-cal approach to obfuscation. Thislighthearted touIch ca1rr-ied over to thesmIloker ws hich inlCtIcled neairly 2 hoLIrsof remiiniscences b\y senlior iellibers ofthe profession ( Harold F. Vokcs. TuL-lane Univer-sity ).

Interdisciplin1arxl- mixing( of verte-brate and plant eViidence was cvidentin a sx 'mIpOSiLlium onl late Paleozoic toearly Mesozoic cliimaitic change (Stanle,yJ. Olsen, University of Florida). Alloiutic elemiienits were conisiderecd in auAirvey knocledge of CretLcCous pa'le-ogeography (Karl N4. \aage, YaleUniversity). The significance of com-l)uters \v,as considlered Iromi dlata stor-age, thrcouLgh modelin, of shapes, toquantification ol distribUtiOn (DavidM4. Raup. University of Rochester).A sx,mposiuLml ex, okint considerable

inter-est was devoted to aItypical preser-vation of fossils (EuLgene S. RichaLrdson,Jr., Field MLuSeml of NatUral History),whereby the occurrenice of soft-bodiedorganisms was examinied. Some half-dlozen localities in the wsorld have pro-vided keyholes throuLgh which to viewthe forms that have otherwise not beenpreserved in the last 600 million years23 JANUARY 1970)

Why doesn't somebody design aninverted microscope specifically fortissue culture and other biological studies?

.. ,

omebod as, seThis is no modification. It's the newest, hi'ghest state-of-the-art in

1-

inverted microscope design and construction. In mechanical prec-sion. In optical quality. And in conveniences, operating speed and ease.

It's the first of its kind, a typical Wild classic. Write for Booklet M40.

WIlD0 WILD HI4EERUG INSTRUMENTS, INC.PARMINODALE, NEW YORK 11735

-f41l In Canada: Wild of Canada Ltd..Fctfory Services 881 Lady Ellen Place, Ottawa 3, Ontario

Circle No. 26 on Reoders' Service Card -'99

15 cu-.ft. Refrigerated Incubator

<0111 ,,,k I$495Ar7777777l7-

FROMfff:j -;- | - -:f \STOCK/It's really that simple. Our refrigerated incubator Model 352700 has a full loadarea of 15 cu. ft. with precisely controlled temperatures from +2' to 50'C plusextraordinary uniformity of -'-0 40Ci The average 10 cu. ft. incubator selling at thesame price, actually has only 7 cu. ft. of usable space. We makethis an unprece-dented bargain by including both high and low safety thermostats! Order today or

write for literature: Hotpack Corporation, 5086 Cottman Ave., Phila., Pa. 19135,(215) 333-1700.

Circle No. 81 on Readers' Service Card

Sharpens any blade in only 3 minutesrevolutionary PERMA-SHARP

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At last!a machtransfobadly ca condidirectl!and prcclass se

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IN LESS THAN 3 MINUTES BYAN UNSKILLED OPERA TOR!

Price $ 835.00 completeF.O.B. Fairfield, New JerseyWRITE FOR BROCHURE

Circle No. 78 on Readers' Service Card

of earth history. Recent finds of orga-nisms of Pennsylvanian age near Chi-cago are particularly noteworthy aniwere feaLtured in a special museum ex-hibition. Coinicidentally, the finding otsoft parts of conodonts was reported:small phosphatic toothlike structureshave been known since 1856, buLt theirbiologic position is enigmatic.

Paleontology is not a science givento spectacular scientific breakthroughs.However, it is a steadily maturing antigrowing field of inquiry. The NorthAmerican Paleontological Convenitionshows the profession to be in a buLshealthy state. Because the meetingsprovided both a survey of the kinid ofwork puLrsued and the current state ofthe numerous activities, plans are unl-der way to publish a nuLmber of thesymposia in the near futuLre.

ELLIS L. YOCI-IFLSONU.S. Geolog-ical Survey,W(shin-toWn, D.C.

Courses

Correction: The date for ElectroniMlicroscopy in the Biological Sciences(see p. 212 . 9 Jan.) should have been9-27 February. The other informationremains unchanged.

Fermentation Technology, Cambridge.Mass., 22-26 JuLne. This summer programwill emphasize the application of biologi-cal and engineering principles to problemsinvolving microbial and biochemical sys-tems, review fuLndamentals, and provide anup-to-date account of current knowledgein fermentation technology. Deatllinie forapplicaItion.v: 15 May. (Director of Sum-mer Sessions, Massachusetts Institute ofTechnology, Cambridge 02139)

Training in Nuclear Materials Safe-guards, Argonne, 111., 30 March-22 May.The program for assuming responsibilitiesin safeguards and nuclear materials man-agement is being offered in four segments.althotugh designed as a unit. Individual,may enroll for one or more segments, butall should attend the final workshop week.Introduction to Nuclear Technology, 3('March-10 April: Measurements in NLI-clear Materials Safeguards, 13 April-1May; Fundamentals of Nuclear MaterialbControl, 4-15 May; and Workshop irSafeguards, 18-22 May. The fees arc$150 per week. (Dr. Manuel A. KanterSafeguards Training Program, Argonn(Center for Educational Affairs, Argonne111. 60439)

Organic Mass Spectrometry, St. LouiisMo., 2-5 March. The main subject areaare basic aspects of mass spectrometry instrumentation, interpretation of the mas,spectrtum, high-resolution techniques. combined gas chromatography mass spectrometry, and computer processing of mas

spectral data. (Dr. Ram L. Levy, Divisioiof Continuing Professional EducationWashington University, Box 1048, StLouis, Mo. 63130)

SCIENCE, VOL. 16I

400