SOlIE MOE: 21) Auguist 1974\ol. 185, No. 4152

Some people areon top of their job.

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Circle No. 466 on Reoders' Service Card

For laboratories weighing costsas well as samples, a precisiontop-loader for only $495.

Today more than ever before, cost is amajor consideration when purchasing newlaboratory equipment. If your lab needs amodern, efficient top-loading balance, theSartorius 104 is your best answer from everystandpoint, including price.

The 1104 is a precision-made torsionbalance with 1,000 g capacity/0.] g ac-curacy, ideally suited. for a wide variety ofstudent, research and industrial applications.Design-wise, it incorporates many advancedfeatures: all-digital readout, full-range opticalscale, built-in mechanical taring, readings inless than 3 seconds, no beam oscillation, andno weights to handle or dial in. A non-fatigu-ing torsion band system eliminates the needfor knife edges.

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New opportunities in molecular filtration:

The Concentrationof Macromolecules

Current ApplicationsCurrent applications of molec-

ular filtration include concen-trating macromolecules fromcolumn chromatography eluates,viruses from water supplies andcell lysates, proteins from cellextracts, lipopolysaccharidesfrom bacteria and Bence-Jonesprotein from urine. Enzymesand nucleic acids can also beconcentrated with minimaldenaturation.

Standard MethodsMacromolecules typically are

concentrated by precipitation,pressure dialysis, lyophilization,evaporation, ultracentrifugation,chromatography, and molecularsieving. Although widely used,these methods have one or moreof the following disadvantages:They are either slow, cumber-some, damaging to molecules,expensive, or multiprocedural.

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Millipore and MolecularFiltration

Millipore has developed fil-tering materials and equipmentof unique design which have

Circle No. 291 on Readers' Service Card

shown considerable achieve-ment in the manipulation ofmacromolecules. Other adver-tisements in this series discussapplications in drug binding,virus purification, deproteiniza-tions, and water purification.We invite inquiries concern-

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HandifluorT ScintiIIAR,Rbrings you 50 to 100Omore counting efficiency at 30 to 50% watercontent.

You'll like its performance at five per centwater content. At 50%o you'll love it. And thatincludes the tough jobs, like tritium at lowconcentrations.

A complete cocktail for scintillation counting,Handifluor ScintillAR gives you brilliant clearsolutions or firm translucent gels on aqueous ornon-aqueous samples. Counting efficiency stayshigh at both low and ambient temperatures.

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SCIENCE PRODUCTS DIVISIONSaint Louis. Missouri 63147

GENERAL AQUEOUS SAMPLES

Approx. Absolute Tritium Efficiency (Percent)Ml Aqueous WaterPhase Per Percent Handifluor Cocktail Base10 ml Base By Vol. Cocktail Base A BNone - 53.7 48.9 50.80.5 5 44.5 42.9 44.51.0 9 40.5 37.1 39.51.5 13 37.5 35.6 36.62.5 20 35.0 34.1 32.93.5 26 31.0 31.3 32.35.0 33 29.8 19.9 28.27.5 43 24.1 10.7 22.4

10.0 50 20.7 9.8 19.6*10 ml of base, tritium equal to 2,000 dpm and aqueous phasegiving the indicated percentage of the total cocktail combinedand counted by a Packard Model 2425 Tri-CarbR LiquidScintillation Spectrometer. Instrument efficiency for :;H byA.E.S. was 97-99%, representing 58-60% absolute tritiumefficiency vs. sealed standards. Data represents averages offour successive 10 minute counts. Efficiencies are expressed aspercent of the theoretical decompositions per minute actuallycounted.

After you've read the chart, what more canwe say except that it's ready to be delivered toyou in SafemorR0 gallon jugs from your localMallinckrodt distributor. Catalog No. 4022. Ifyou'd like even more data, ask for our completecomparative data sheet.

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The First WLde RanWeMirotome-cryostat...Temperatures from-150C to -500C...FIrozen SectionsfromIOajc to2cs .The Harris LoTemp model WRCis two microtome-cryostats inone. A single unit that can doboth routine diagnostic pro-cedures and such sophisticatedresearch procedures as thinsection light microscopy, auto-radiography, fluorescence mi-croscopy and other histologicalprocedures, at a cost compar-able to presently availableroutine cryostats.The Harris model WRC is

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LETTERS

Metrication: Historical Perspective

The tone of A. Hunter Dupree's let-ter, "Metrication as cultural adaptation"(19 July, p. 208), is exemplary, but re-grettably his arguments are not. Likethe English, who "could have profitedfrom our ... experience when they cameto decimalize their coinage," Dupreedoes not appear to benefit from history.

If we consider that the greater partof the world uses the metric system,there is surely no shortage of examplesof how countries with varying socialand technological characters originallymanaged their "cultural adaptations."Investigation reveals that the generalconcern was not to look back to pre-serve a marginal and relatively unim-portant aspect of heritage, but to effecta practical reform for future genera-tions in a world where intercommunica-tion was increasing. But perhaps afterall it is this looking backward thatmakes our case unique: carpenters inFrance are presumably able to repairbuildings somewhat older than those inProvidence, Rhode Island, without call-ing for a return to the toise.To write that wholesale metrication

involves "destroying one culture andsubstituting another" is to give an exag-gerated importance to quantitativemeasurement in the cultural life of anation. Whether it was the Romansgiving the British a metric system twomillenia ago, or the French giving it tothe world in the last century, no culturaldark ages appear to have followed therapid withering of old measuring sys-tems. No doubt some mourned thepassing of miles and leagues, as todaysome mourn the passing of the steamlocomotive. But we don't need to bethe first country genuinely at homeusing both diesel and steam locomotives.

P. A. MOHRAstrophysical Observatory,Slnithsonian Institution,Cambridge, Massachusetts 02138

Dupree speaks of making "the UnitedStates . . at home using two or moremeasuring languages." He seems to beoverlooking the fact, that we are atpresent using four systems of measure-ment: metric, engineer's, machinist's,and English (and a fifth if you includehorse racing). All of this is patentlyridiculous; engineers measure in tenthsof a foot while machinists measure intenths of an inch, with no commonground anywhere.

Circle No. 454 on Readers' Service Card

Dupree's point about carpentersworking on old buildings is also badlytaken. Lumber sizes in use today arenot the same as those used 200 yearsago, so it does not matter in the leastwhether old construction members aremeasured in cubits, inches, or centi-meters when being replaced or repaired.

Speaking of carpenters, it might benice to have a bit of honesty broughtinto our lumber sizing. Why should apiece of lumber measuring 1 8s by3 `/ inches be called a two-by-four?Calling it a four fifteen-by-nine twenty-five (its actual size in centimeters)would be honest and descriptivelystraightforward.

JAMES FANNINGByram Lake Road, Route 2,Mouint Kisco, New York 10549

Cancer Research in the WrongDirection?

Bandwagons have always existed andthere will always be those who jumponto one. Sometimes it is creative anduseful to do so, but usually it involvesa sacrifice of original ideas. To survivein research, unfortunately, people areforced to do such things.

Cancer research has become a boom-ing business for some groups in thepast few years because the people andthe government want a cure for can-cer. Tissue culture has emerged as arespected science of tremendous im-portance. But business and industryhave crept in there too. In addition toculture dishes and media, animal cellshave become a commercial product.One can buy cells by the kilogram froma supplier. This is certainly an advan-tage, and since cancer researchers havestarted using commercial cells, mostlyof two kinds (3T3 and W138), consider-able amounts of information have beenaccumulated about the biology of thesecells.What have we found and what does

it mean? We have learned that virusesand chemicals can transform 3T3 cellsto a neoplastic state and that these cellscan produce tumors when inoculated insuitable hosts. But the tumors producedby these cells are sarcomas (derivedfrom fibroblasts), which are very rare inhuman beings; 90 percent of humantumors are carcinomas, which arederived from epithelial cells. So whatdo we gain from growing sarcoma-producing cells in tissue culture exceptpublishing papers and doing research to

SCIENCE, VOL. 185

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You really should read them both...The publication in your handcontains current technicalinformation of vital importanceto your professional research.So does the Calbiochemcatalog. Our editors strive tobe informative, entertaining'and brief in their uncluttereddescription of more than 2000authentic research biochem-icals. Calbiochem's publica-tions and products areavailable throughout theworld. If you want a free sub-scription to our publications,send your name and profes-sional address to Ms. H. Gone,c/o Calbiochem, P.O. Box12087, San Diego, California92112. Ask for our currentBiochemicals and Immuno-chemical Reagents List.

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Circle No. 335 on Readers' Service Card

64723 AUGUST 1974

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(49

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23 AUGUST 1974

stay in research? Epithelial cells- andfibroblasts have little in common ex-cept that they are both animal cells;they are derived from two embryonicsources with different functions, and thetumors they produce are also different.Also, 3T3 is a cell line associated withabnormal chromosomal conditions,which makes it even less desirable forcancer research.Why can't people at least try to re-

produce the disease that is occurring inthe human body? Conversely, if theywant to cure a disease occurring in thehuman body, they must be able tocreate an analogous condition in tissueculture. So, why can't carcinomas beinduced in tissue culture? The simplereason is that it is very difficult to ob-tain and culture pure epithelial cells.They can not be manufactured com-mercially. The investigator has to spendtime and energy to generate epithelialcells. This problem has been recognizedby all tissue culture scientists. On thecontrary, cells like 3T3 grow wild inbottles and are available in plenty. Thisis simply closing one's eyes to a chal-lenging problem and doing somethingthat is not useful in terms of the long-range goal of curing cancer.

B. K. NAIRDepartment of Community andEnvironmental Medicine, Univer.sity ofCalifornia, Irvine 92664

Some foreign students will continuetheir education at other institutions.They may not have the opportunity orinclination to continue their studies ineducation. However, during their train-ing at Prairie View, they are encour-aged to develop instructional moduleswhich include autotutorial lessons,workbooks, visual and audio aids, andevaluation criteria specifically designed(in terms of language, customs, andrelevant problems) for use in theircountry. The student is also encouragedto consider our institution as a linkfor the exchange of information dur-ing his professional career.Many of our staff have served in

technical assistance programs and areaware of the special skills and personalattributes needed to successfully trans-fer knowledge (considering the differ-ent mores and environments) in devel-oping countries. This experience isutilized in modifying courses to meetthe needs of our foreign students.

Baez's proposal has our full en-dorsement, and we suggest that AAASmembers at each university involved ininternational work meet annually toexchange ideas regarding the prepara-tion of foreign students as teachers ofscience in their homelands.

EUGENE A. BRAMSJAMES I. KIRKWOOD

Departmnetnt of Plant and Soil Sciences,Prairie View A & M University,Prairie View, Texas 77445

International Agricultural Education

We agree with Albert V. Baez (Edi-torial, 26 Apr., p. 417) that the effec-tiveness of foreign assistance can beenhanced by transferring the art ofteaching science to the scientificallytrained foreign graduate students re-turning to their homelands from U.S.institutions. We at Prairie View, withthe assistance of a grant from theAgency for International Development,are committed to the premise that agri-cultural technology can be acceptedand utilized by the grassroot farmersof developing countries through ap-propriate educational methodologytaught to young scientists. We are pres-ently developing a proposal for re-searching a delivery system for thetransfer of agricultural technology tothe rural poor. One phase of this sys-tem includes the education and train-ing of our graduate students, who, inaddition to their technical courses, arerequired to pursue a minimum of 9credits in education of the 36 requiredfor a master's degree in soil sciences.

Wisdom Shortage

Comparisons are invidious. The truthof this is admirably illustrated by PhilipAbelson's editorial "Media coverage ofsubstantive issues" (31 May, p. 941).Relieved of its self-congratulatory, rath-er narcissistic praise for Science and itsstrictures against less exalted media, theeditorial makes a number of goodpoints. Both their import and theirimportance are lost, however, in theirritation engendered when one learnsthat Science is "designed to informrather than to excite," that Science"can [if it wishes] produce a morerounded, complete, balanced, and schol-arly story" than, presumably, the dailypress.

Science should show a decent reluc-tance to claim a monopoly on wisdom,if for no other reason than that it isin critically short supply.

DANIEI S. GILLMOR70 Perry Street,New York 10014

649-

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THE GLC-2 CENTRIFUGECOSTSA LITTLE MORE.

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