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The Most-Cited Physical-Sciences Publicationsin the 1945-1954 Science Citation Index.

Part 1. Fifty-two Citation Classics inPhysics and Chemistry

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Two years ago we published the 1945-1954 Science Citation Index” (SCF’ ) cumul-ation, extending our coverage of the scien-tific literature back to the post-World WarII era and permitting detailed citation analy-sis of research during that period. 1z Lastyear, Bernard Dixon, former editor of NewScientist and currently contributing editor toBiotechnology, reviewed the 102 most-cited life-sciences papers identified in the1945-1954 cumulation.q In this essay, wepresent the first of a two-part review byStephen G. Brush of highly cited physical-sciences papers from that era.

Brush is a professor in the Department ofHistory and the Institmtefor Physicaf Seieneeand Technology, University of Maryland,College Park. He brings an impressive ar-ray of credentials to the task of reviewingpostwar physicaf-sciences literature. A na-tive of Orono, Maine, he received his under-graduate degree in physics summa cumlaude from Harvard College, Cambridge,Massachusetts, in 1955 and his PhD intheoretical physics from Oxford Universi-ty, UK, in 1958. He held a Rhodes Scholar-ship at Oxford (1955-1958) and a NationaJScience Foundation Postdoctoral Fellowshipat ltnperiaf College, London (1958-1959).4

Brush was employed as a physicist at theLawrence Radiation Laboratory, Liver-more, California, from 1959 to 1965. Heconducted theoretical research on the prop-erties of matier at high temperatures andhigh pressures and on the history of kinetictheory and statistical mechanics. Among hiscontributions to theoretical physics was thefirst computer calculation showing that anidealized classical plasma would exhibit a

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phase transition to an ordered solid state.This result has been used in recent studiesof stellar and planetary stmcture.

After three years at Harvard, as a writerfor the “Project Physics” course for highschools and a lecturer on physics and thehistory of science, Brush came to the Uni-versity of Maryland in 1968 as the fust full-time historian of science there. He helpedto organize the Committee on the Historyand Philosophy of Science, which adminis-ters a graduate degree program in coopera-tion with the Departments of History andPhilosophy. He teaches and directs graduatework in the history of science, especiallyphysical sciences and mathematics since1500. He has continued to lecture and writeon the uses of history of science in scienceeducation, the creation-evolution contro-versy, and women in science. 4

Brush has published three monographs ontopics in the history of science. lke Kindof Motion We Call Heat: A History of theKinetic l%eoty of Gases in the 19th Century(1975)s won the Pfiier Award of theHistory of Science Society. The others areThe Temperature of History: Phases of Sci-ence and Culture in the 19th Century(1977)6 and Statistical Physics and theAtomic l’heory of Matter from Boyle andNewton to Las&u and Onsager (1983).7He is coauthor, editor, and translator of 12other books on physical science and its his-tory, and of more than 1(KIarticles and bookreviews. His most recent book is ?%eHistory of Modem Science: A Guide to theSecond Scientific Revolution, 18#1950.sRecent articles are “Prediction and theoryevacuation: the case of light bending, ” pub-

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lished its Science,g and “Theories of tie or.igin of the solar system, 1956-1985,” whichappeared in Reviews of Modem Physics. 10

Brush is president of the History of Sci-ence Society (through 1991); he has chairedthe society’s education committee, hasserved on its council and the editorial boardof its journal, Isis, and has been itsWashington representative. He was found-ing editor of the History ofPhysics IVewslet-ter. He is a fellow of the American PhysicalSociety (APS) and a member of the APScouncil, representing the history of physicsdivision. He is also a fellow of the AmericanAssociation for the Advancement of Sci-ence, and a corresponding member of theInternational Academy of the History ofScience,

At the University of Maryland, Brush hasbeen named a “Distinguished Scholar-Teacher” and has served as chair of thefaculty council and president of the localchapter of the American Association of UN-versity Professors. He is a member of theFaculty Voice editorial board.

The frostpart of Brush’s study surveys themajor trends and researchers in physics and

chemist~-the two fields that almost exclu-sively dominate the list of most-cited phys-ical-sciences papers from the postwar era.At the very top of the list, as Brush dis-cusses, is Linus Pauhng’s TheNature of theChemical Bond and the Structure of Mole-cules and Crystals: An Introduction toModem Structural Chemistry. ~~ As wenoted in a tribute to Pauling last year, thisis one of the most highly cited publicationsof all time. 12Pauling discussed the book ina 1985 Citation Classic@ commentary. 13

Physics and chemistry, of course, do nottell the entire story of postwar research inthe physical sciences. In a forthcomingessay, we will present the conclusion to thisstudy, in which Brush will examine keymid-century research in smaller physical-sciences fields, such as mathematics, geo-sciences, astronomy, and astrophysics.

*****

My thanks to Christopher King and Enc7hurschweU for their help in the prepara-tion of this essay.

REFERENCES

1. GarfSeld E, cd. Science Cimtian frrd.a fen year cunrukzrion1945-1954. Pbifadelphla: Jnstitute forScientific Information, 1988. 10 VOIS.

2. -—-—. The new 1945-1954S(Y cumulation provides unique access to the cruckd postwar decsdc ofscientific aad technological achievement. Current Cmuenfs (27):3-10, 4 July 1988.

3, Dixon B. The 102 most-cited life-sciences publications in the new 1945-1954 Science Cikztirmtna%x.Parts 1 & 2, Current Conrents (15):4-10, 10 Aprif 1989; (16):3-10, 17 April 1989.

4. BrushS G. Personaf cmmmmication. 5 April 1990.5. -—--—. lhe kind of motionwecatl heat: a history of the kinetic theory of goses in the 19th century.

Amsterdam, The Netherlands: North Hoffand, 1975.2 vols,6. -----—-. Zhe tempemture of history: phases of science and culture in the l%h century.

New York: Frarddii, 1977, 210 p.7. ----------- Statisrica/ physics and rhe atom”c theory of matler j?om Boyle and Newton to Lamriru and

Onsager. Princeton, NJ: Princeton University Press, 1983.324 p.8. --------- 71rehistory of modem science: a guide to the second scient~c revohttion, IL% B1950.

Ames, IA: Iowa State University Press, 1988.544 p.9. -------=. Prediction and theory evaluation the case of light bending. Science 24&1124-9, 1989.

10. -—-—-. Theories of the origin of the solar system, 1956-1985. Rev, Mod. Phys. 62(1):43-112, 1990.11. PaaUag L. The nature of the chemical bond and the structure of molecutes and crystals: an tntraduction

to modem smwuml chemistry, Rhaca, NY: ComelJ University Press, 1960.644 p.12, Gtileld E. Linus Paroling an appreciation of a world citizen-scientist and citation laureate.

Cwrenr Contems (34):3-11, 21 August 1989.13. Pmrtirrg L. Ckmion Classic. Commentary on 7he nature of the chemical bond and the soucture of

nralectdes and crysta)s: an introduction to nrcdem structural chemistry. Ithaca, NY: CornellUniversi~ Press, 1939, 429 p. Current Coraents/Engineering, Technology & Applied Sciences16(4):16, 28 January 1985 and CC/Physicaf, Chemicol & Earth Sciences 25(4): 16, 28 January 1985,

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The Most-Cited Physical-Sciences Publicationsin the 1945-1954 Science Citation hdex

Stephen G. BrushDepartment of History andInstitute for Physical Science and TechnologyUniversity of MarylandCollege Park, MD 20742

This essay examines the 52 most highly cited papers and books in the physical sciences, 1945-1954,based on the Science CitationIndexe cumulationfor that decade. It discusses SQrmof the major trends,achievements, and researchers in the physicaf sciences in the period including World War II. Com-parisons are made between citation frequency and other measures of importance, such as Nobel Prizesand judgments by historians of science. Virtuallyaflof the 52 most-citedphysicaf-sciencespublica-tionspresentedin the Bibliography at the end of this essay are in physics or chemistry. MaUer fieldswith lower citation frequencies, such as mathematics, geosciences, and astronomy/astrophysics, arenot well represented. In Part 2, we will identify and discuss high-impact works from these fields.

Introduction: The Top Five CitdionClassics of 194S-1954

A few years ago, when I was trying to ert-courage chemists to take an interest in thehistory of their discipline, 1I asked them asimple question: Who do you think is themost important chemist of the twentieth cen-tury? Who shotdd be presented to the publicas the hero of modem chemistry, corre-sponding to Albert Einstein, who has beatextensively promoted as the hero of modemphysics? Having read a lot about how chem-istry is a science in which experiments aremore vahrable than theories, and having seenhow much chemists dislike being told thatchemistry can be reduced to physics, I wasunprepared for the answer.

Every member of this small and unsys-tematically selected sample, after express-ing some puzzlement that anyone should asksuch a strange question, finafly came up withthe same answer: Linus Pauling. Yet Pau-Iing is best known for his development of

the themy of molecular structure-a theorybased directly on physics!

After that experience it was no surpriseto learn that Pauling’s book, 27reNature ofthe Chen”cd Bond and the Stracture of MoI-ecules and C~stals: An Introduction toModem Structural Chemistry, was the mosthighly cited publication in the physical sci-ences during the decade 1945-1954. Thetotal number of citations for the 1939 and1940 editions was 571 during this period.Citations to all editions of this book num-ber more than 16,000, according to ananalysis by Zelek S. Herman, Linus Pau-ling Institute of Science and Medicine, PaloAlto, Califortria.z There were more than600 citations to all editions of the book inthe 1989 Science Citation Indexm (SCP ).

Publications in chemistry were also thesecond, third, and fourth most cited duringthat period, which cart be seen in the Bibli-ography at the end of this essay. A 1938paper by Stephen Brtmauer and Pauf H.Emmett, then at the Bureau of Chemistry

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and Soils, Washington, DC, and EdwardTeller (widely acknowledged to be the in-ventor of the hydrogen bomb), GeorgeWashington University, Washington, DC,on “Adsorption of gases in multimolecularlayers” received 450 citations. It, too, is acontribution to theoretical chemistry usingconcepts borrowed from physics—although,as in Pauling’s monograph, comparisonswith experimental data play an importantpart.

The monograph on the 7heory oj RateProcesses (1941) by Samuel Glasstone,Keith J. Laidler, and Henry Eyring, Prince-ton University, New Jersey, cited 418 times,was written in paII (according to its preface)to show how much progress had been madein calculating absolute reaction rates byusing quantum mechanics and statisticalmechanics. The Ultracentn@ge (1940) byTeodor Svedberg, Kal O. Pedersen, andJohannes H, Bauer, University of Uppsala,Sweden, received 381 citations; it describesa physical method of great utility to chem-ists. Not until we reach the fifth mbst-citeditem, “Table of isotopes” (1948), cited 259times, by Glenn T. Seaborg and I. Perhnan,Department of Chemistry and RadiationLaboratory, University of California,Berkeley, do we fmd a publication on phys-ics itself rather than on its application tochemistry.

While chemistry dominates the five mosthighly cited papers, the physicrd sciences asa whole account for only 11 percent of thetop 250 most-cited papers in the 1945-1954SC1 cumulation. ISI@ therefore decidedto publish two separate articles: one byBernard Dixon, former editor of New Sci-entist and currently contributing editor toBiotechnology, surveying the 102 most-cited articles in the life sciences,s and thisone, devoted only to the physical sciences.

Citation Data Vary by Fie!d

‘fhis decision reflects the view that the ab-solute citation count for a publication is lesssignificant than its citation count relative toother works in the same field. Some fieldssimply have a bigger literature than others—

more authors, more papers, more citations.Thus, as Eugene Garfield has pointed out,any list of most-cited papers for all of sci-ence must make allowances for field or dis-ciplinary differences: “The most-citedworks in fields like botany, radioastronomy,mathematics, and so on, would not turn upon this undifferentiated list.”4

Indeed, the list of 250 most-cited worksfrom the 1955-1964 SCI ornits astronomy,mathematics, the earth sciences, and otherrelatively small fields.4 And the list of the52 most-cited books and articles in1945-1954 presented here is composedalmost entirely of publications in chemistry(25) and physics (25); there are only 2 inmathematics, and none in astronomy or theearth sciences. Rather than omit mathemat-ics, astronomy, and the earth sciences, 1S1is compiling additional lists for those fields,which will be presented and discussed in thesecond part of this essay.

With the exception of a small-scale cita-tion study of 16 physics journals of the1920s,s the new 1945-1954 SC1cumulationrepresents the earliest period for which ci-tation data are now available.b This com-pilation thus offers an exceptional oppor-tunity to look back at a historic period ofscience and see what articles were CitariorrC.kzssics” during this time.

Of the 52 publications most cited from1945 to 1954,5 were published before 1935and 3 appeared after 1949 (a detailedchronological breakdown for all the physi-cal-sciences publications is given in Table1). I will concentrate on the 15-year period(1935-1949) in which the other 44 publica-tions appeared.

Major Developments and lkembzs Physics

The most important advance in twentieth-century physical science was the develop-ment of quantum theory by Max Planck,Albert Einstein, Niels Bohr, Louis deBroglie, Werner Heisenberg, and ErwinSchr6dinger in the period 1900-1926.7-9By1935 the basic principles of quantum me-chanics and their application to the simplestsystems had been firmly established. Thismay be seen from the fact that the 1930 ar-

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Table 1: Cbronologid distribution of pubtkationdates forthephysicahciencespapersandbmksmostcited in the SCF cumulation, 1945-1954.

Publication Number ofYear Papers

1920-1924 11925-1929 01930-1934 41935-1939 81940-1944 171945-1949 191950-1954 3

title on quantum treatment of “Atomicshielding constants” by John C. Slater,Harvard University and the MassachusettsInstitute of Technology, Cambridge, Massa-chusetts, needed no significant revision andwas still highly cited in the 1955-1964decade (336 citations)Q as well as in1945-1954 (176 citations).

Physicists were not satisfied that quantumtheory could give an adequate account of theinteraction betsveen subatomic particles andradiation consistent with relativity theory,but this problem was set aside for a dozenyears. In 1947 Willis E. Lamb and RobertC. Rutherford, Columbia University, NewYork, showed that the energy difference be-tween two excited states of the hydrogenatom, a difference theoretically due to theelectron-radiation interaction, could bemeasured by experiment. 10 This resultprompted theorists to work out detailed cal-culations, leading to the establishment of“quantum electrodynamics,” a theory thatachieved remarkable quantitative agreementwith the experimental results.

Richard P. Feynman, California Instituteof Technology (Caltech), Pasadena, andJulian Schwinger, Harvard University, inthe US, and Sin-itiro Tomortaga, Universi-ty of Education, Tokyo, Japan, irtdependent-Iy developed this theory, for which theywon the 1965 Nobel Prize in physics.Tomonaga’s work was not widely known inEurope and America until after 1947 and isnot represented in the Bibliography. Butboth Feynman and Schwinger published twopapers on quantum electrodynamics thatbecame Citation Ckmrics in the 1945-1954

Xl. The Bibliography aiso lists two papersby another American (originally British)physicist, Freeman J. Dyson, Institute forAdvanced Study, Princeton, which ex-plained and extended the Feynman-Schwinger-Tomonaga theories.

Feynman subsequently became much bet-ter known to the public when he served onthe commission appointed to investigate theChallenger disaster. By dropping an O-ringinto a glass of ice water, he vividly demon-strated the dangers of launching a shuttle incold weather. His two-volume autobiogra-phy (the second volume was published justafter his death in 1988) is a fascinating ac-count of the human side of science. 1I.Iz

The reason the development of quantumelectrodynamics was postponed until the late1940s was of course that physicists werepreoccupied with the atomic nucleus. In1938 Otto Hahn and Fritz Straasmann,Kaiser Wilhelm Institute for Chemistry,Berlin-Dahlem, Germany, performed theexperiment that their colleague LiseMeitner, Academy of Sciences, Stockholm,Sweden, recognized as the discovery of tis-sion. 1sThe theory of this ominous phenom-enon was explained in 1939 by Bohr andJohn A. Wheeler, Princeton University.Meitner’s crucial role in the discovery wasignored when Hahn alone received the 1944Nobel Prize in chemistry and has onlyrecently come to be recognized. 14.15

Of these only the Bohr-Wheeler paper ap-pears in the Bibliography. Its 149 citationsgreatly underestimate the impact of knowl-edge about how fission works because sci-entists soon realized that this knowledge wastoodangerous to be published in a world onthe brink of war. For the next six years,most of the citations to the revolutionarypapers on nuclear fission were confined to[he secret reports of weapons laboratories,not included in the SCI database. This maydso be true of the Cita~ion Classic book bySydney Chapman and T.G. Cowling, Im-perial College of Science and Technology,London, since it was the authoritative sourcem the theory of the diffusion processes usedLOseparate uranium isotopes for the Man-Iattan Project.

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After Hiroshima and Nagasaki, nuclearphysics was largely declassified and occu-pied a significant part of the journrd litera-ture for the next several years. This researchactivity is reflected by several highly citedworks on isoto~s, energy levels, and magn-etic moments of nuclei—F. Ajzenberg andT. Lauritsen, Kellogg Radiation J_aborstory,Caltech; F. Bloch, Stanford University, Crd-ifornia; N. Bloembergen e~ al., HarvardUniversity; Melvin Calvin et al., Universi-ty of California, Berkeley; Eugene Feenbergand Kenyon C. Hammack, Washington Uni-versity, St. Louis, Missouri; M. Goldhaberand A.W. Sunyar, Brookhaven NationalLaboratory, Upton, New York; Emil J. Ko-nopinski, Indiana University, Bloomington;Maria G. Mayer, Argonne National Labo-ratory, Illinois; and Seaborg and Perhnan.

Scientists were extensively involved in thepublic debates about nuclear weapons dur-ing the postwar period. The two most-citedpublications carry the names of scientistswho were on opposite sides of those debates.Pauling won his second Nobel Rlze—the1962 Peace Prize-for his leadership in themovement to ban nuclear tests. Teller, onthe other hand, was an outspoken advocatefor the development and testing of newweapons.

Missing from the list of Citation Classicsis a subfield of physics that had already be-come prominent by 1949 and that was toattract an increasing share of intellectual andfinancial resources in the following decades:elementary particles. Hideki Yukawa’s 1935proposal that nuclear forces are carried bya particle with a mass of about 200 timesthat of the elecrron, and the discovery of thepi-meson by Cecil F. Powell and G.P.S. Oc-chialini in 1947, were recognized by theaward of Nobel Prizes in 1949 and 1950.But the two review articles on cosmic rays(one by Bruno Rossi and Kenneth Greisen,Cornell University, Ithaca, New York, andthe other by Rossi alone) are the only onesin the Bibliography directly related to thksubfield, although the publications on quan-tum electrodynamics mentioned above wereto have some influence on theories of ele-mentary particles. lb

The widening impact of quantum mechan-ics during the period 1935-1949 can be seenin several areas outside of atomic physics.i%e Modem lheory of Solids (1940), a Ci-tation Classic by Frederick Seitz, then at theCarnegie Institute of Technology, Pitts-burgh, Pemsylvania, is an obvious exam-ple, as is his review article on a special topicwithin this field, “Color centers in alkalihalide crystals” (1946). The theory of thesuperfluidity of helium (1941) by L. D.Landau, Kharkov University, USSR, ap-plied quantum mechanical ideas to fluids ina novel fashion that first mystified but ulti-mately enlightened the physics commu-nity. 17

Chemistry

As noted at the begiming of this essay,Pauling used quantum mechanics to explainthe chemical bond and molecular structure.A 1945 book on infrared and Raman spec-tra by Gerhard Herzberg, National ResearchCouncil of Canada, Ottawa, Ontario, and a1941 paper on molecular vibrations byE. Bright Wilson at Harvard, along with the1941 book by Glasstone, Laidler, andEyring on rate processes, also taught manychemists how to use quantum mechanics todeduce by experiment quantitative informa-tion about molecular properties.

An alternative to Pauling’s “valencebond” method was the “molecular orbital”approach popularized by Robert S. Mulli-ken, University of Chicago, Illinois. Thehighly cited 1941 paper on ‘‘Hyperconju-gation” by Mulliken and University ofChicago colleagues Carol A. Rieke andWeldon G. Brown illustrates this approach.Another paper by Mulliken (1952) on themolecular orbital method was a “latebloomer’ ‘—that is, it was more highly citedfrom 1955 to 1964 than in the previousdecade coverai in this study, 1945-1954.Table 2 lists this and nine other “late-bloomer” publications, including anothermolecular orbital theory paper by C.C.J.Roothaan, University of Chicago.

Curiously, historians and philosophers ofscience have largely neglected these major

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. .

Table 2: “Late bfuamers’ ‘–10 physicaf-sciences items publkhed before 1954 that were among the 250 mostcited in the 195S-1964 SCP cumulation but not in the 52 physical-sciences items must cited io the SCImmmfation for 194S- 1954. An asterisk (*) indicates that the item was ttre subject of a Citation (%ssic”commentary. The issue, year, and d]tion of the commentary follow the blbliogcaphic reference. A =totaf nmnbcrof 1945-1954 citations. B = total number of 1955-1964 citations.

AB Bibfiograpkic Data

97 475 Blatt J M & Weisakopf V F. theoretical nuclear physics. New York: Wiley, 1952.864 p,122 356 ● Chartdraaekhar S. Stucbastic problems in physics and astronomy. Rev, Mod. Phys. 15:1-89,

1943. (47/891ET&AS; 47/89/PC&ES)79 404 Cruickshank D W J. Tbe accuracy of elcctrondensity maps in X-ray anafysis with special

reference to dibenzyl. .4cm CrpraUogr. 2:65-82, 1949.73 35-t * Heraberg G. Molecular spectra and molecular structure, I. Spectra of eiiaromic molecules,

New York: Van Nostrand, 1950.658 p. (13/83/PC&ES)23 325 * McWeeny R. X-ray acattcring by aggregates of bundcd atoms. 1. Analytical approximations in

single-atom scattering. ,4cm CrysfaUogr, 4:513-9, 1951. (17/8 I/pC&ES)79 403 Muffiken R S. Molemdar compounds and their spectra, ff. J. Amer. Chem, WC. 74:811-24,

1952.I 35 459 Racak G. Theory of complex spectra. II. Phys. Rev. 62:438-62, 1942.47 352 Ruothaan C C J. New developments in molecular orbital theory. Rev. Mod. Phys. 23:69-89,

1951.20 355 ShuckfeyW & Read W T. Statistics of the recombination of holes and electrons. Phys. Rev.

87:835-42, 1952.115 438 * Vmr Vleck .1 H. The dinolar broadening of maenetic resonance lines in cnwals. Phw. Rev..

74: 1168-8;, 1948. (3i/79/PC&ES) -

contributions to the foundations of chemistrywhife giving perhaps excessive attention tothe foundations of physics. 1 Thus the IsisCumulative Bibliography 19761985, whichlists nearly all publications on the history ofscience published during this period, hasonly 5 items on Pauling and 3 on Mulliken,compared to 234 on Einstein, 33 on Bohr,26 on Heisenberg, 16 on Phtnck, 15 onErnest Rutherford, 13 on de Broglie, and12 on Robert Andrew Millikan, Cakech. ]gSince one of the articles on Pauling alsodeafs with Mulliken, the total for both au-thors is onfy seven. Other works by Paulingare listed in the Crifica[ Bibliography ofthe Histoq of Science and Its Cultural ht-jluences, published annurtfly in Isis. In thiscase the citation data are especially valuablein calling attention to influential contribu-tions in a large body of technical literaturethat few nonspecialists can understand.

While the largest number of chemistry Ci-tation C!assics (6 out of 25) involve the ap-plication of quantum mechanics, afmost asmany (4) deaf with polymers. As Paul J,Flory, then at Esso Laboratories, StandardOil Development Co., Linden, New Jersey,author of two of these papers, redled inhis Nobel lecture, Hermann Staudinger hadestablished by about 1930 that polymers are

covafently linked molecules, rather than ag-gregates of smaller molexules. 19The firstattempt at a mathematical description of theirspatial configurations was pubfished in 1934by Werner Kuhn, University of Basel,Switzerland. The subject was further dis-cussed in a 1943 paper by Kuhn and HansKuhn, afso at the University of Basel. Bothpapers are listed in the Bibliography.

The Kuhn theory was based on a simpli-fied model, the molecule being representedby the “random walk” of a point particle.Flory made a significant improvement bytaking account of the “excluded volume ef-fect’‘—thefact that two segments of the mol-ecule (unliie the path of a moving point par-ticle) cannot occupy the same space. Flory’swork led to major advances in understand-ing the propefiies of polymers, substancesthat also have considerable technological im-portance. 19 He identifies his own key con-tribution to the subject as a paper publishedin 1949 and does not mention the earlier pa-pers listed here.

Nobel Laureates

For physics and chemistry, the obviousquestion about any list of highly cited works

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is: How many were authored by Nobellaureates? And how many Nobel Prize-winning papers don ‘tappear on the “most-cited” list?

There are 78 authors for the 52 most-citedpublications (some of them being authors ofmore than one item). If one omits the twomathematicians (Stefan Banach, Universi-ty of Lvov, USSR, and Harald Cram&, Uni-versity of Stockhohn, Sweden), there are 18Nobel laureates among the 76 physicists andchemists. They are listed in Table 3, whichalso shows the year in which they wereawarded the prize.

Eleven items in this study list at least oneNobel physicist author. Since 1 of the 25physics publications was coauthored by aNobel chemist (Seaborg), one could also saythat 48 percent of the most-cited physicspublications were written by Nobellaureates. And there are 11 items with atleast one Nobel chemist author. Of the 25chemistry items, 10 (including two editionsof Pauling’s book) or 40 percent were au-thored by a chemistry Nobel laureate.

This is not to say that the publicationsidentified here are necessarily the Nobellaureates’ prizewinning works. As pointedout by Garfield, the most-cited publicationsby Nobel laureates are sometimes not theones for which they won the prize.zo Insome cases the prize is given for a body ofwork rather than a single publication. More-over, it is stifl possible for a scientist to winthe Nobel Priie in the future for work doneduring this period. For example, the 1989prize in physics went to Norman Ramsey,Harvard University, for his research on mo-lecular beams in the late 1940s.z1

Another reason many Citation Classicsdon’t win Nobel Prizes is that they do notreport original research discoveries. hstead,they describe useful new experimental in-struments or methods, or they review prog-ress in a field or compile data. I estimatethat only about 40 percent of the items inthe Bibliography are first reports of originalresearch.

Of the Nobel laureates in this study, Bohr,Lars Onsager, and Svedberg won it for workdone before they published the Citation

Table 3: Nubef Isoreates tkted ss authors nf the rnmt-cited pbysicaf-aeienccs pspmx and books in the1945-1954 SCP, showing the field und year of heirawards.

NobelLst Field Ymr

Bloch F Physics 1952Bluembergen N Physics 1981Bohr N Physics 1922Calvin M Chernisoy 1%1Feynman R P Physics 1965Flory P J Chemistry 1974Herzberg G chemistry 1971Landau L D Physics 1962Mayer M G Physics 1963Mott N F Physics 1977Mulliken R S Chemistry 1966Onsager L chemistry 1%8PaulinS L Chemistry 1954

Peace 1962Purcell E M Physics 1952Schwinger J Physics 1%5.%ahurg G T Chemistry 1951Svedberg T Chemistry 1926Ziegler K Chemistry 1963

C.kssics listed here. Calvin, Herzberg,Nevill F. Mott, and Pauling were honoredfor research originally published in journals;their Citation Classics are monographscovering the same and related subj@s. Sim-ilarly, Seaborg’s and Mayer”s highly citedpapers are compilations of data relevant totheir research. Bloembergen, Feynman,Flory, Landau, Mulliken, Purcell,Schwinger, and Karl Ziegler won the NobelPrize for research that does include paperson the most-cited list.

Onsager is the only Nobel laureate on thelist whose highly cited paper is on a subjectclearly different ffom the research for whichhe received the prize. He received the prizefor a 1931 work on reciprocal relations inirreversible processes .22,23But I considerhis solution of the two-dimensionaf Lsingproblemzd more significant than that workm his paper on electric moments in~iquids17included in the list.

Mathematics

The books by Banach (1932) and Crarm%[1945), the otdy mathematics publicationsin the Bibliography, are Citation Classicsfor rather different reasons. Cram6r’s com-

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Table 4 The 198S SCF research fronts that include at least one of the 1945-1954 most-cited physical-sciencesitems as core documents. The names of first authors fromthe Bibliographyappearin parentheses. A = rmmbcrof Bibliography items that are core to each research front. B = total number of core documents. C = total numberof 1988 citing papers.

Number Name

88-fsM6 Polymer mixtures, binary blend void systems, statistical rhermmdyrramics, andMonrc-Carlo simulations of lattice models (Flory)

88-0082 Superdefonrred states of rotating nuclei, complex fragment emission, gamma-rayspcctrowopy, high angular momentum, and intermediate energies @obr)

88-0141 Superfluid He-4, interatomic potentials, deep inelastic neutron-scattering, collkioninduced spectmscopies, and long-range 3-bGdy interactions (Lamlau)

88-0465 Symmetcicaf hydrogen-baded ice, contimrum model proton tramfer, dynamics ofsolitons, amorphous Si02, high-pressure phases, and bonding defects (Eternal)

88-1474 Nucl=-spin relaxation, nematic phase, themtotropic liquid crystats, proton NMR,and spectd densities for isotropic interrnolemtar interactions (BIoembcrgen)

88-3298 Sodium tetmhydroborate, efficient reduction of acyl cbforides, and living catiordcpolymerization (Nystrom)

88-3360 Adsorption of water, anomalous synthetic tobermorites, and surface characteristics(Brunauer)

88-4626 Electrical-resistivity in Y% CU107.J, ferromagnetic Ni-baae ~loYs, ~d thinanti ferromagnetic fdms (Mott)

88-4982 Symmetry group transformation operators in the interaction piCNKe and quantumfluid at nonzero temperature (Dyson, Feymrran)

88-5199 Unified photon dosimemy approach, pencil barn kernels, and arbitrary dosedistributions (Rossi)

88-8156 Molecular vibrations, infrared spectroscopic &ta, and ethyl bromoacetnte (Wilson)

prehensive treatise was useful to many sci-entists because it presented modem mathe-matical models that could be convenientlylearned and applied to problems requiringstatistical analysis. Banach’s monographstimulated further research by mathemati-cians working in harmonic analysis, partirddifferential equations, algebra, and topolog-ical vector spaces. Although Cramt?r’s bookwas more dmtly applicable to empirical re-search in the physical sciences, Banach’s hada closer intellectual relation to the theoreticalapproach that dominated physics and chem-istry in the second quarter of the twentiethcentury.

Banach (1892-1945) seems to have had nointerest in quantum mechanics and it wouldbe difficult to show that it had any infhtenceon his ideas. Nevertheless, his work onlinear operators and the invention of‘‘Banach space” fall squarely within the tra-dition that provided the mathematical foun-dation for the versions of quantum mechan-ics developed by Schrbdinger, Paul Dirac,John von Neumann, and Feynman.Z5~zbThe key idea in this tradition is to generalizethe idea of a‘ ‘space, ” originally defined in

ABC

1 11 136

1 37 338

1 38 329

1 33 306

I 12 147

I 3 21

1 2 118

1 4 35

2217

1 5 27

1213

terms of a few variables (x,y,z), whosevah.tesare numbers, to spaces of@rctions;these can be regarded as spaces with an in-finite number of dimensions. In quantummechanics the state of a system is repre-sented by a wave function that may betreated as belonging to a ‘‘Hilbert space, ”a special cstse of the more general spacestudied by Banach. The “linear operators”in the title of Banach’s Citation Chssicmonograph correspond in quantum mechan-ics to physical entities like energy and mo-mentum, whose values can be found by let-ting the operators operate on the wave func-tion,

Research Fronts, Chronological andNational Diitrilmtions, and Journals ofthe Top 52 Physical-Sciences Ci$ationclassics

Table 4 lists current 1988 research areasthat frequently cite one or more of the itemsin the Bibliography. The cited items are con-sidered part of the “core” for the “researchfronts, ” as determined by an algorithm de-veloped at ISI.Z7-Z9Items in a core must be

174

Table 5: The number of authors per paper for the 36physicaf-sciencs.s papers most cited in the SCI@cumulation, 1945-1954.

Number of NumberAuthors of

per Paper Papers

5 14 13 42 111 19

related to each other by co-citations, andmust also satis~ a minimum “citationstrength” criterion that weights each cita-tion relative to the total number of citationsin the reference list of the citing paper. Thisprocedure should to some extent mitigate thebias against fields such as mathematics inwhich articles have shorter reference lists.

It is interesting to note that both of the corepapers in research front #88-4982, ‘‘Sym-metry group transformation operators in theinteraction picture and quantum fluid at non-zero temperature, ” are Citation (Yassics in-cluded in this study— Dyson’s 1949 paperon the Tomonaga-Schwinger-Feynman ra-diation theories and Feynman’s 1949 paperon the space-time approach to quantum elec-trodynamics. That these and other works ofcomparable age are still co-cited in currentresenrch fronts indicates that they have notbeen “obliterated by incorporation. ” Thisphenomenon, described by sociologistRobert K. Merton,so Columbia University,

Table 6 Natiomd Incatinm of the fnatitutfonalNIUationa listed by authors in the Bibliography,according tn total appmmnces (column A). B=numberof items cnautfrored with researchers affiliated withinstitutions in other countries. C= national InCationsof institutions listed by coauthors.

connt3y AB c

us 37 2 Camda, DenmarkUK 6Canada 21 usGermany 2Sweden 2Switzerland 2Denmark 11 usPoland 1USSR 1

Table Z The Jourmata that published the 36 paperslisted [n the Bibliography. The numbers inparentheses are the 1988 impact factors for thejournals. (The 1988 impact factor eqmds the numberof 1988 citations received by the 1986-1987 articlesin a joumat divided by the number of articles publishedby the journal during the same period.) Data weretaken from the 1988 JCR@ The figures at the rightindicate how many papers from each jnumat appearin the Bibliography,

Number ofJournal Papers

I Phys. Rev. (N/A) 13J. Amer. Chem. Snc. (4.57) 8Rev, Mnd, Phys. (15.13) 6J. Chem. Phys. (3.59) 3

2 Bcr. Deut. Chem, Ges, B (N/A) 1HeIv, Chim. Acts (1.97) 1

3 Ind, Eng. Chem. Amd. J?zl. (N/A) I4 J. Phys. SSSR (N/A) 15 Just. Liebigs Ann, Chem. (N/A) 1GKolloid Z. Z. Polym, (N/A) 1

1 Divided in 1970 into Phys, Rev. A—Gen. Phys,(2. 32), Phys. Rev, B–Solid State (changed in1978 to Phys. Rev, B—Condensed Matter[3.82]), Phys. Rev. C–NUC1. Phys. (2.01),and Phys. Rev. D—Part. Fields (2.33)

2 Merged with Ber. Deut. Chem. Ges. A in 1947to form Chem. Bar. (1 .53)

3 Changed to Anal. Chem. (3.98) in 19474 Published 1939-1947s Changed to Llebigs Ann. Chem. (1, 10) in 1979GChanged to CoUoid Pnlym. Sci. (0.95) in 1974

and discussed by Garfield,31 refers to im-portant discoveries that have become socompletely integrated into scientificknowledge that authors no longer feel a needto cite the original publication.

Other statistical characteristics for the 36articles in this study are given in Tables 5-7:the number of authors per paper, mtionali-w based on authors’ institutional affiliations,andjournal of publication, respectively (ex-cept for the table showing mtionalities, thesethree tables exclude this study’s 16 books).

Conch?skma

In this essay I have tried to sketch a fewof the scientific developments of the 1930sand 1940s and to contrast the visibility ofthose developments at mid-century, as mea-sured by citation frequency, with their im-

175

portance as perceived in subsequent de-cades.

Since some science departments now usecitation counts in evaluating faculty for pro-motion and tenure, it should be emphasizedthat most of the papers that are later judgedto contain outstanding discoveries were nothighly cited by contemporaries. Thus onecannot dismiss publications as insignificantmerely because they are not frequently cited(even relative to other papers in the samejoumals).32

For historians and others interested in un-derstanding the science of a particularperiod, citations (to say nothing of the moresophisticated kinds of citation analysis nowused in the discipline of scientometrics) canbe quite revealing. The fact that a publica-tion was highly cited shows that it was visi-ble to the scientific community for sorrterea-

1.

2,

3.

4.

5.

6.

7.

8,

9.

10.

Il.

12.

13.

14.

15.16.

17.

18.

19.

son; one must then look at the citing articlesto find out why it was cited, In some cases(e.g., the article by Brtmauer et al. on ad-sorption) one karrts about important originalresearch that may have been neglected byhistorians of science. The list of articles thatcited a publication is also extremely helpfulin studying how and why a theory or dis-covery was accepted or rejected by the sci-entific commutity, which I demonstrated ina historical study of theories of the originof the solar system .33

As those who have participated in the sci-entific enterprise have learned (sometimesby bitter experience), it is not sufficientmerely to publish your ideas and results; youmust also persuade other scientists to acceptthem. The SCI offers a valuable tool for in-vestigating the dynamics as well as the struc-ture of science. <,,s,W

REFERENCESBrush S G. Why chemistry needs history-and how it can get some. J. COU. Sci. Teach. 7:288-91,

1978,HermarsZ S. The twenty-fivemost-citedpublicationsof Lirrus Patding. (Huemer R P, cd.) 7he roors of

molecular medicine: a tribute to Linus Prruling. New York: Frmnan, 1986. p. 254-9,Dmon B. The 102 nrnst-cited Iife-scierrces publications in the ocw 1945-1954ScienceCitation Index.

Parts 1 & 2. Current Contents (15):4-10, 10 April 1989; (16):3-10, 17 April 1989,Garfield E. The 250 most-cited Citation Ckz.mics from the essential decade 1955-1964. Essays of an

information scientist: ghostwriting and orher essays. Pbitadelphia: 1S1 Press, 1986. Vol. 8, p. 37-49.Smrdl H. Physics Citarion Index, 15EW1929. Philadelpbiw fnstitute for scientific Information, 1981.

2 VolsGarfield E. The new 1945-1954 SCI cumulation provides ursique access to the crucial pstwar decade of

acientitic and technological achievement. Currenr Contents (27):3- 10, 4 July 198S.Segr+ E. From x-rays to quarks: modern physicists and their discoveries. San Rartcisco,CA: Freeman,

19s0. 337 p.Heifbron J L, Wbeaton B R, May J G, Rider R & Robinson D. Literature on the history ofphysics

in the 2&h century. Berkeley, CA: OffIce for History of Science and Technology, University ofCalifornia, 1981.485 p.

Brush S G & BeUord L. lhe history of modem physics: an international bibliography. New York:Garland, 1983.334 p.

Lamb W E & Retfrerford R C. Firre structure of tbc hydrogen atom hy a microwave nrerfrod.Phys. Rev. 72:241-3, 1947.

Feynrrmn R P. “Surely you ‘re joking, Mr. Feynman!” Adventures of a curious characrer. New York:Norton, 1985.350 p.

-.-- —------- . “What do YOU care whet other people rhmk ?‘’ Further adventures of a curious characrer.New York: Norton, 1988.255 p.

Meitner L & Frisch O R. Letter to c&tor. (Disintegration of uranium by neutrons: a new type ofnuclear reaction.) Nature 143 :239d0, 1939.

Krafff F. Internal and external conditions for the discovery of nuclear fission hy the Rerlin team. (SheaW R, ed. ) Otto Hahn and rhe rise of nuclear physics. Snston, MA: Reidel, 1983. p. 135-65.

Dickman S. Meitner receives her due. Narure 340:497, 1989.Weinberg S. Tbe search for unity: notes for a history of quantum field tbeury. Dae&lus

10&17-35, 1977,Brush S G. Statistical physics and the atomic theory of matter from Boyle and Newron to l.anrzhu rmd

Onsager. Princeton, NJ: Princeton University Press, 1983, p. 244-6.Neu J, ed. Isis cumukrtive bibliography 197tL1985. Bnston, MA: Halt, 1989, 2 vols.

Pforv P J. SDStial confimmmiorr of nracromolecrdas cbsins. (Odelfxm? W. ed. ) La Pri.r Nobel en 1974.;tnckbolrn. Sweden: -Norstedt & Wrer. 1975. D. 104-25 -

176

20.21.22.23.24.

25.26.

27.

28.

29.

30.

31.

32.

33,

Gartleld E. Dn Nobel f%ze winners write Cimrkm Cfassics? Op. cir., 1988. Vol. 9. p. 182-7.Pod R. Basic measurements lead to physics Nobel. Scienre 246:327-8, 1989.Onaager L. Reciprocalrelations in irreversible prncesses, 1. Phys. Rev. 37:405-26, 1931,------------, Rcciprccalrelationsin irreversible prncesses, If. Phys. Rev. 38:2265-79, 1931.--------- Crystal statistics. 1. A two-dmensionaf mndel with an order-disorder transition, Phys. Rev.

65:117-49, 1944.Stefnfmru H. Stefan Banach, 1892-1945. Ser. Math. 2693 -lMt, 1961.Bemkopf M. The development of timctinn spaces with particular reference to their origins in integral

equation tieocy. Arch. His?. Eracr. Sci. 3:1-96, 1966,Smafl H & Sweeney E. Clustering the Science Citation Irrdcx using ccwitations. 1. A comparison of

methods. .$cienkmrreoics 7:391-409, 1985.Smafl H, Sweerrey E & Greerdee E. Clustering the science Citarion hdc.r using co-citations. 2.

Mapping science. Scientometrics 8;321 -40, 1985.Small H & Garfield E. The geography of science: disciplinary and national mappings, J. hrform. Sci.

11:147-59, 1985.Merton R K. On the shoulders of giants: a Sharrdcan postscnjrt. San Diego, CA: Harcourt Brace

Jovanovich, 1985. p. 218-9.Garfield E. The “obliteration phenomenon” in arience-and the advantage of being obliterated!

QP. cit., 1977, Vol. 2. p, 396-8.----------- How to use citation ansfysis for faculty evaluations, and when is it relevant? Pacts 1 & 2.

fbirf., Vol. 6. p. 3S4-72.Bnrah S G. ‘flrcuries of the origin of the solar system 1956-1985. Rev, Mod. Phys. 62(1) :43-1 12, 19913.

BIBLIOGRAPHY

The 52 pbyaicaf-aekmces papers and hook moat cfted brthe SCF’ cunndation, 1*1954, listed in alphabeticorder by first author. Numbers folIowing the bibliographic entcy iodicate the 1988 SC1/SSCF research-frontspecialties for which these are core papers. An asterisk (*) indicates that the item waa the subject of a CitationCTossic” commentary. The issue, year, and edition of the cmnmcnqwy fohw the bibfiogmphic reference. A =trrtalnumber of 1945-1954 citations. A dagger (t) indicates that the item has been previously identified in an essayon the 250 most-cited items from the 1955-1964 SCI cumulation. (See reference 4).

A Bibwaphic DatIs

146 Ajsenberg F & Larrrif-sen T. Energy levels of light nuclei. Ff. Rev. Mod. Phys. 24:321-402, 1952.167 Banach S. ?leorie &s operations lineaires (77reory of linear operations). Waraaw, Poland Z

subwencji Funduszu kultury narndowej, 1932. 254 p.142 Rarrer R M. Difiion in and through $olitilr. Cambridge, UK: Cambridge University Press, 1941.

464 p.179 Berrmf J D & Fowler R H. A theory of water and ionic snlution, with particular reference to

hydrogen and hydroxyl ions. J. Chem. Phys. 1:515-48, 1933.88-0465175 Barry J W, Chappefl D G & Barnea R B. Improved method of flame phaomet~. Ind. Eng.

Chem. And Ed. 18:19-24, 1946.257 Blchowsky F R & Roasini F D. ‘fhe therrnachemistry af the chemical sabstanres. New York:

Reinhold, 1936.460 p.147 TBfoch F. Nuclear induction. f%ys. Rev. 70460-74, 1946.199 *tBloembergen N, Purcell E M & Pound R V. Relaxation effccta in nuclear magnetic resonance

absorption. Phys, Rev. 73:679-712, 1948. (18/77) 88-1474I49 Bnhr N & Wheeler J A. The mechanism of nuclear fission. Phys. Rev. 56:426-50, 1939.88-0082143 Brockmann H & Sdmdder H. Ahmdniumoxyd tit abgestuflem Adaorptionsvermngen zur

chromstographischen Adsorption (Ahuniomrr oxide with graduated adaurption capacity inchromatographlc adsorption). Ber. Deut. Chem. Ges. B 74:73-8, 1941.

450 *tBmnauer S, Emmett P H & Tefler E. Adaocption of gaaes in multimolecular layers. J, Amer.Chcnr. SoC. 60:309-19, 1938. (35/77) 88-33El)

140 Cafvfn M, Heidelberger C, Reid J C, Tolbert B M & Yarrkwich P F. Isotonic carbon: techniquesin its measurement aud chemicaf rnaaipufation. New York: Wtiey, 1949. 376 p.

185 Chapman S & Cowfing T G. ‘lhe mathematical theory of mm-urr$own gases: an account of thekinefic theory of viscosity, thcrrnol condti”on, and difliesion in gases. Cambridge, UK: CambridgeUniversity Press, 1939.404 p.

177 * Crarm% H. Mathematical method.i of statistics. Uppsala, Sweden: Almqvist & Wkaeffs, 1945.575 p. (28/83/PC&ES)

219 Dysnrr F J. The S matrix in quantum elwtrndynanrics. Phys. Rev. 75:1736-55, 1949.191 Dyson F J. The radiation theories of Tomonaga, Schwinger, and Feynmarr. Phys, Rev. 75:486-502,

1949, 88-4982

177

A BibliographicData

141160195

150

216

418

243240

222

173152

140

140

162

146

255

165

154

I50

148

223

143

169

153

418

I86227187197

259140176176381

140

168

FeerrbergE & Ihrrrrmck K C. Nuclearshellstructure.Phys. Rev. 75:1877-93, 1949,Feyrunan R P. The theory of pnsitrons. Phys. Rev. 76:749-59, 1949.FeyssrsrarsR P. Space-time appmacb to quautrmr electrcdyrramics. Phys, Rev, 76:769-89, 1949.

88-4982Flory P J. Molecular weights and intrinsic viscosities of polyiaobutylenes. J. Amer. Chem. SOc.

65:372-82, 1943.* Flory P J. Tbermndynamics of high polymer sohnions. J. Chem, Phy$. 10:51-61, 1942,

(18/85/ET&AS; 18/85/PC&ES) 884)046*tGlaaatone S, Lakffer K J & E@rsg H. 77re them-y of rare processes: the kineb’cs of cherrdcal

renctions, viscosity, di@rion and electrochemical pherrorrrena. New York: McGraw-HM, 1941.611 p. (1 l/85/ET&AS; 1l/85/PC&ES)

GnhfJraber M & Sortyar A W. Classification of nuclear isomers. Phys. Rev, 83:906-18, 1951.* Heraberg G. Molecular spectra and rrrolecukrr structure. II. lnfiared and Rarmrn spectra of

pdyaeorrric rrrdecrdes. New York: Van Nostrarrd, 1945.632 p. (13/88/ET&AS; 13/88/PC&ES)Huarsg-Mhrlon. A simple mndifrcation of the Wolff-Kisfmer reduction. J. Amer. Chcm. .%.

68:2487-8, 1946.Knsropimaki E J. Beta-decay. Rev. Mod. P/Iys. 15:20945, 1943.Krsbrs W. Uher die Gestalt fadenformiger Molekiile in Lbsungen (Shape of fibre-forrning molecules

in solutions). Kol(oid Z. Z. Polym. 68:2-15, 1934.KubrrW & Kuhn H. Die Frage nach der AufroOung vmr Fadenmolekeln in strbmenden LiMungen

(Coiling of fdamentmy molecufes in flowing liquids). He/v. Chim. Acto 26:1394-465, 1943.Landau L D. Theory of superfluidity of He U. J. Phys. SSSR 5:71-90, 1941. g8-0141Latfreser W M. Y?reoxidation states of the elements and their potentials in aqueous solutions. New

York: Prentice-Hall, 1938.352 p.Lewis G N & RarrdaIi M. 7herrnodyrwmics orrd the free energy of chemical substances. New York:

McGraw-Hill, 1923.653 p,Mayer M G. Nuclear cotilguratinns in the spin-orbh couplig mndel. 1, Empirical evidence. Phys.

Rev. 78:16-21, 1950.Mott N F & Gurney R W. Electronic processes in iorric crysral$. Oxford, UK: Cfarendon Press,

1940.275 p,Mott N F & Jrmea H. 77re theory of the properties of metoh and alloys. Oxford, UK: Clarendnn

Press, 1936.326 p. 884626Mnzfrsgn R, Wolf D E, Harris S A & Fnlkers K. Hydrogennlysis of sulfur cnmpcrunda by Raney

rnckel catalyst. J. Amer. Chem. Sot. 65:1013-6, 1943.Muflkken R S, Rieke C A & Brnwrs W G. Hyperconjugatinn. J. Amer. Chem. Sot. 63:41-56,

1941.Nystrom R F & Brnwm W G. Reduction of organic compounds by lithium afumismm hydride. 1.

Aldehydes, ketones, esters, acid cbforides and acid anfrydrides. J. Amer. Chem. Ser. 69:1 I97-9,1947.88-3298

Nyatroart R F & Brnwn W G. Reduction nf organic compnunds by lithhmr ahmrirrum hydride. D.Carbnxylic acids. J. Arrrer, Chem. Snc. 69:2548-9, 1947.

Onaager L. Electric mnments of molecules in liquids. J. Arrwr. Chem, &x, 58:1486-93, 1936.

* Paufing f.. i’le nature of the chemical bond and the structure of molecules ond crystals: anintroduction 10 modem structural chemiwy. Ithaca, NY: Cornell University Press, 1939. 429 p.(4/85/ET&AS; 4185/PC&ES)

* Pmsl@ L. 371t nature of the chemical bond and thr structure of molecules orrd crystafs: anintroduction to modem structural chemistry. Ithaca, NY: Comeff Urriversity Press, 1940. Lcnsdnn:Oxford University Press, 1945.450 p. (4/85/ET&AS; 4/85/PC&ES)

Roaai B. frrterpretatinn nf cosnric-ray phenomena. Rev. Mod. Phys. 20:537-83, 1948.Rtwsi B & Grefaen K. Cosmic-ray the-my. Rev. Mod. Phys. 13:240-309, 1941.88-5199Sehwksger J. @ammrr electrodynamics. I. A covariant fnrmrdation. Phys. Rew 74:1439-61, 194g.Srhwissger J. Quantum electrodynamics. II. Vacumrr pnlariration and self-energy. Phys. Ro.

75;651-79, 1949.Seahorg G T & Perfman L Table nf iantopes. Rev. Mod. Phys. 20:585-667, 1948.Seifa F. Cnlor centers in alkafi halide crystals. RerJ. Med. Phys. 18:384408, 1946.Seita F. 31e modem theory of soli~. New York: McGraw-Hi3f, 1940.698 p.

~Slater J C. Atomic shielding constama. Phys. Rev. 3657-64, 1930.‘tSvedberg T, Pederress K O & Basser J H. 7he uhracenmfige. Oxford, UK: Clarendon Press,

1940.478 n.● Wflaors E B. Sosnr mathematical metbnds for the study nf mok?cuk vibrations, J, Chem. Phys.

9:76-84, 1941. (1 l/81/PC&ES) 88-8156Ziegfer K, Spath A, Sehsraf E, S’chrrmmm W & Wmkefrrtarm E. Die Halogerriemng unge.wmigter

Substanzen in der Allylstellung (l’be hafogemarion of unsaturated substances in the allylic pnsirion).Just. Liebim Ann. Chem. 551:80-119, 1942.

178