After a double-take...read the fine printHere are two Beckman pH meters made to look alike...but which are sig-nificantly different internally. Both instruments provide broad flexibility,precision, and a high degree of accuracy in electrochemical measurement.

ZEROMATICa If pH METER...When youneed an instrument for general lab pHmeasurements, look to the ZeromaticII. This is an instrument ideally suitedand designed for general-purpose use inthe laboratory. The taut-band meter,with an 8.2-inch scale, offers the ulti-mate in readability and permits read-out over theOto 14 pH orOto +700mvrange, which may be extended up to± 1400 mv. It is a line-operated instru-ment with the capabilities required formost applications.EXPANDOMATICO pH METER ... Whenyou need an instrument for more pre-cise pH measurements on an expandedscale to spot minute differences in pHor millivolts, the Expandomatic shouldbe used. A standard scale covering thefull 0 to 14 pH (O to ± 1400 mv) range

14 OCTOBER 1966

is available for ordinary pH and milli-volt measurements. An expanded scaledisplays any 2 pH units or 200 milli-volts over full scale with ±+0.01 accu-racy. A logarithmic scale, correspondingto the expanded scale, permits the cor-relation of any two pH units with theirhydrogen-ion activity.Otherwise, these two pH meters have

the same outstanding features: ±+0.05relative accuracy and 4 0.015 repeat-ability over the full standard scale; anextra large, taut-band meter that is pre-cise and highly readable; easy-to-usepush button controls for convenientoperation; a die-cast aluminum caseresistant to chemicals; a continuouslyadjustable temperature network whichcovers the full 0 to 100°C temperaturerange; and a drift-free performance am-

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fessional meet every writing problem of his working day-fromarticles and reports to simple memos. For fifteen years the authorhas served as a writing consultant to large and small companies, andhas dealt with the various branches of science, management, andtechnology. 1966. 337 pages. $5.95.

APPLIED COMBINATORIAL MATHE-MATICS. Edited by EDWIN F. BECKEN-BACH, University of California, Los Angeles.Special attention to problems in the biological,social, physical, and mathematical sciences. 1964.608 pages. $13.95.

MECHANISMS OF ANIMAL BEHAVIOR.By PETER MARLER, The Rockefeller Univer-sity; and WILLIAM J. HAMILTON, III, Uni-versity of California, Davis. A unified treatmentof the physiological, psychological, and zoologicalviewpoints on the mechanisms that control ani-mal behavior, with examples drawn from bothvertebrate and invertebrate behavior. 1966. 771pages. $14.95.

EXPERIMENTAL TECHNIQUES INELECTRON SPIN RESONANCE. ByCHARLES P. POOLE, JR., University of SouthCarolina. The only book that shows how to buildand use an electron spin resonance spectrometer,and how to obtaift the maximum amount of in-formation from the data provided. Most completebibliography yet available. An Interscience Book.1966. In Press.

INTRODUCTORY COMPUTER PRO-GRAMMING: FORTRAN, Logic, Statisti-cal Problems, Mathematics, 110 Exercises.By FREDRIC STUART, Hofstra University.Designed to train professionals in diverse fieldsto do their own programming, including physicaloperation of the console. 1966. 115 pages. $5.95.

PRIMATES: Comparative Anatomy andTaxonomy. Volume 6: Catarrhini Cercopithe-coides Cercopithecinae, A Monograph. By W. C.OSMAN HILL, Zoological Society of London.The latest in an impressive and lavishly illus-trated series of monographs. An InterscienceBook. 1966. 757 pages. $45.95.

INTRODUCTION TO SOLID STATEPHYSICS, 3rd Edition. By CHARLES KIT-TEL, University of California, Berkeley. A com-pletely modern revision of the standard book inits field, with clear explanations and many illus-trations. 1966. Approx. 624 pages. $12.50.

MATHEMATICAL METHODS IN THEPHYSICAL SCIENCES. By MARY L. BOAS,DePaul University. Problems-ranging from sim-ple drill exercises to a few that could be shortpapers-parallel the book's coverage of virtuallyevery area of mathematical physics encounteredin the physical sciences. 1966. Approx. 712 pages.$11.95.

SIGNAL DETECTION THEORY ANDPSYCHOPHYSICS. By DAVID M. GREEN,University of Pennsylvania and Bolt, Beranek, &Newman; and JOHN A. SWETS, Bolt, Beranek,& Newman. A systematic analysis of psycho-physical problems from the viewpoints of statis-tical decision theory and statistical communica-tion theory. 1966. 455 pages. Prob. $12.95.

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SCIENCE, VOL. 154206

ColumbiaPaPerback(s

*SCIENCE IN THE MAKINGBy Joel H. Hildebrand; This book con-

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*THE ATOMS WITHIN USBy Ernest Borek; Winner of the 1961Thomas Alva Edison Founda-tion Award for the best sciencebook for youth, THE ATOMSWITHIN Us recounts the historyof biochemical research, itsmethods, its discoveries, and itsgoals. No. 3 5 $1.95

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minimum flush-out Gerard estimatedfor rapid mixing. If temporary multi-ple sluices were provided within bothdams at appropriate depths, the Soundcould be purged through them ratherthan by spillover. Because of salinity-density stratification, the water flow-ing through the submerged sluiceswould be considerably more salinethan surface overflow. For sluice flowto match flow into the reservoir, -thewater level in the fresher Sound mustbe sufficiently above that in the sea tomore than offset 'the pressure head ofthe denser sea water overlying thesluices. Furthermore, the sluices musthave sufficient capacity for the effec-tive pressure difference to handle res-ervoir influx. These requirements, con-sidering the lack of tide in the reser-voir, seem practical without land en-croachment.

Fresh water influx can pump out salt-ier water than that which would over-flow the dams *in the plan suggestedby Gerard.

HAROLD LAMPORTDepartment of Physiology, Mt.Sinai School of Medicine, New York

One possible benefit that Ger-ard does not mention is the creationof a freshwater harbor by removal ofmaterial needed to build the dam. Adam 20 m high, 50 m wide at the top,90 m wide at the bottom, and 12.8km long would contain 18 X 106) m3of material. This is sufficient to createa hole, which might be used as aharbor, 18 m deep and 1 km square.Such a harbor near the mouth of theConnecticut River could provide suf-ficient capacity to relieve some of thecongestion in New York Harbor.

W. I. NEEFE. T. MERRILL

Battelle-Northwest, P.O. Box 999,Richland, Washington 99352

Chemotaxis: Divided and Defined

At one time I sided with Disraeli's"I hate definitions." Now it seemsas though science proceeds by appli-cation of the razor and hone to defini-tions and I have switched to Emer-son: "He shall be as a god to me,who can rightly divide and define."Chemotaxis, as defined by Fraenkeland Gunn (1), is a "directed orienta-tion reaction," and implies somethingabout the mechanism of the response.

216

It is not yet clear whether the re-sponses shown by Escherichia coli aredirected or random in orientation, butAdler ("Chemotaxis in bacteria," 12August, p. 708) proposes that themechanism used by E. coli is the"avoiding reaction," which Fraenkeland Gunn (2) favor as a randomkinesis. Since Adler's data are not con-cerned with responses per se, but withthe end result of the responses, I sug-gest that these and other similar resultsbe described as aggregation, or betteryet, chemical attraction, a phrase whichdescribes the end result with no com-mitment to mechanism. A general defi-nition of chemical attraction whichmay be useful to others in this fieldis: responses that serve to bring andkeep organisms within the vicinity ofan attractant (3).

Such quibbling over words doesnot detract from the elegant natureof Adler's experiments. But I feel thereis something to be gained by adheringto Fraenkel and Gunn's definitions ofchemotaxis and related terms, or im-proving these definitions.

AUSTIN J. MACINNISDepartment of Zoology, University ofCalifornia, Los Angeles 90024

References

1. G. S. Fraenkel and D. L. Gunn, The Orien-tation of Animals (Dover, New York, 1961),pp. 10, 53.

2. , ibid., p. 57.3. A. J. Maclnnis, J. Parasitol. 51, 733 (1965).

Of Porpoises and Bedbugs

This is a time for rejoicing. Ourmilitary researchers (who will spend$7 billion during the next year) havediscovered that the porpoise can heused to find enemy submarines bv 1if-ferentiating metals (New York Times,23 April), and the bedbug, by its"yowl" when sensing human flesh, mayhelp to hunt the Vietcong (New YorkTimes, 6 June).An Office of Military Zoology is

clearly needed to cultivate this newfrontier of science. What valuable spill-over for civilian technology may comefrom these efforts! Perhaps the new Of-fice of Military Zoology could give usthe boon of an anti-bedbug (ABB), azoological equivalent of the anti-ballis-tic missile (ABM).

SEYMOUR MELMANIndustrial and ManagementEngineering, Columbia University,New York 10027

SCIENCE, VOL. 154

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Classical Thermodynamics

In Thermodynamics (Prentice-Hall,Englewood Cliffs, N.J., 1966. 256 pp.,illus. $7.95), J. T. Vanderslice, H.W. Schamp, Jr., and E. A. Masonpresent basic principles and appli-cations of classical thermodynamicsin a well-organized and concise man-

ner. The concept of heat is treatedon the mechanical basis. The presenta-tion of the second law follows essen-

tially the classical Clausius-Kelvin ap-proach. The law is stated in terms ofwhat cannot be done with a singleheat reservoir. The law is logically de-veloped by elimination of those proc-esses that violate it when a single reser-

voir is involved. The novelty of presen-

tation has the appeal of logical ele-gance, although some may feel that itis an unnecessary luxury.On pages 174 and 175 it is stated that

"an isolated system is in equilibrium ifand only if AS<0" and that this followsfrom the Clausius inequality. The"only if" part has not been shown and,in fact, cannot be shown to followfrom the Clausius inequality. TheClausius-Kelvin statement of the sec-

ond law tells us only what will nothappen (decrease of entropy of isolat-ed systems); it does not tell us whatwill happen spontaneously (increaseof entropy). That maximum entropy(compatible with specified constraints)is a necessary condition of equilibriummust be postulated independently ofand in addition to the Clausius-Kelvinstatement, as has been done by Gibbs.Kramers, T. Ehrenfest, and Belinfanteconsidered this additional postulate as

the third independent part of the sec-

ond law. Many texts are vague on theneed of additional assumption here,which is poor authorship. The difficultyoriginates from the historical develop-ment of thermodynamics, which be-gan as a theory of heat and heat en-

gines, for which the Clausius-Kelvinstatement is sufficient. It later developedinto a more general theory concerningthe physical phenomena of equilibrium,the laws of which go beyond those ofthe heat engine, and an additional basicprinciple must be introduced. The needfor an additional postulate is themajor shortcoming of the classical ap-

proach, though the issue is eclipsedby the successful development of statis-tical thermodynamics. In their recentattempts to reformulate the second law,Landau and Lifshitz, Tisza, Callen,Fong, and Belinfante try to overcome

this difficulty by presenting classical

256

thermodynamics as a macroscopic the-ory of equilibrium, the laws of whichare more general and include the lawsof heat engine as a special case. Theclassical approach of Clausius and Kel-vin is interesting, useful, and histori-cally important, and it is perfectly jus-tifiable to present thermodynamics ac-cording to this approach in an un-sophisticated first course, provided itslimitations and the additional postulateare stated clearly. In this case the con-cept of heat might as well have beentreated from the calorimetric point ofview; the sophistication of the mechani-cal treatment seems a bit out ofbalance.A variety of applications to physical

and chemical systems are discussed.The most important topics for a one-semester course ate all covered. Theseinclude electric," magnetic, radiation,and surface systems, in addition to themore basic physical and chemical sys-tems. Enough variety is provided todemonstrate the generality of the ther-modynamic methods. One would wishthat the discussion of the radiationfield had included the Wien displace-ment law as a preparation for discus-sion of Planck's law of black-body ra-diation; such a discussion would be use-ful to students and is usually not foundin other courses.

PETER FONGLawrence Radiation Laboratory,University of California, Berkeley

New BooksGeneral

American Intellectual Histories andHistorians. Robert Allen Skotheim. Prince-ton Univ. Press, Princeton, N.J., 1966.338 pp. $6.95.An Annotated Bibliography of Mexican

Ferns. George Neville Jones. Univ. ofIllinois Press, Urbana, 1966. 331 pp. $5.

Checklist of Palaearctic and IndianMammals, 1758 to 1946. J. R. Ellermanand T. C. S. Morrison-Scott. British Mu-seum (Natural History), London, ed. 2,1966. 818 pp. £6 6s.Domebo: A Paleo-Indian Mammoth

Kill in the Prairie-Plains. Frank C. Leon-hardy, Ed. Great Plains Historical Assoc.,Lawton, Okla., 1966. 63 pp. Illus.Paper, $2.50.

Directory of Electronic Circuits: Witha Glossary of Terms. Matthew Mandl.Prentice-Hall, Englewood Cliffs, N.J.,1966. 240 pp. Illus. $10.

Elections and the Political Order. AngusCampbell, Philip E. Converse, Warren E.Miller, and Donald E. Stokes. Wiley,New York, 1966. 395 pp. Illus. $8.75.The Engineer. C. C. Furnas, Joe Mc-

Carthy, and the Editors of Life. Time

Inc., New York, 1966. 200 pp. Illus.$3.95. Life Science Library.

Essential Works of Pavlov. Edited andwith an introduction by Michael Kaplan.Bantam Books, New York, 1966. 406 pp.Illus. Paper, $1.25.The Geography of Northwestern Eu-

rope. F. J. Monkhouse. Praeger, NewYork, 1966. 544 pp. Illus. $9.50.

Gravimetric and Celestial Geodesy. Aglossary of terms. Ivan I. Mueller andJohn D. Rockie. Ungar, New York,1966. 141 pp. Illus. $5.Human Ecology. Jack B. Bresler, Ed.

Addison-Wesley, Reading, Mass., 1966.480 pp. Illus. $9.75. Reprints of 36 papersfrom various journals and published be-tween 1953 and 1964.

Inland Fisheries Management. Alex Cal-houn, Ed. Dept. of Fish and Game, Re-sources Agency, Sacramento, Calif., 1966.552 pp. Illus. Paper, $3.84. There are76 papers.

Instructional Media and Creativity. Pro-ceedings of the Sixth Utah Creativity Re-search Conference (La Jolla, Calif.),August 1964. Calvin W. Taylor andFrank E. Williams, Eds. Wiley, NewYork, 1966. 421 pp. Illus. Paper, $3.95;cloth, $8.95. There are 13 papers.

Irrigation. Josef D. Zimmerman. Wiley,New York, 1966. 534 pp. Illus. $12.50.

Magnetohydrodynamics. Alan Jeffrey.Oliver and Boyd, Edinburgh; Interscience(Wiley), New York, 1966. 260 pp. Illus.$3.50.Megalopolis Unbound: The Supercity

and the Transportation of Tomorrow.Claiborne Pell. Praeger, New York, 1966.243 pp. Illus. $5.95.Modern Masterpieces of Science Fiction.

Sam Moskowitz, Ed. World, Cleveland,Ohio, 1965. 528 pp. $5.95. Twenty-oneshort stories, dating from 1935 to 1962.The Moon. V. A. Firsoff. New Ameri-

can Library, New York, 1966. 127 pp.Illus. Paper, 60¢.The Nerves of Government: Models

of Political Communication and Con-trol. Karl W. Deutsch. Free Press, NewYork, 1966. 352 pp. Paper, $2.95.

October the First Is Too Late. FredHoyle. Harper and Row, New York, 1966.206 pp. $3.95. Science Fiction.

Organic Reaction Mechanisms, 1965.An annual survey covering the literaturedated December 1964 through November1965. B. Capon, M. J. Perkins, andC. W. Rees. Interscience (Wiley), NewYork, 1966. 360 pp. Illus. $9.50.

Origins of Mendelism. Robert C. Olby.Schocken, New York, 1966. 204 pp. Illus.$6.95.The Peyote Religion among the Nav-

aho. David F. Aberle. Aldine, Chicago,1966. 480 pp. Illus. $10.Phenomenology and Physical Science.

An introduction to the philosophy ofphysical science. Joseph J. Kockelmans.Duquesne Univ. Press, Pittsburgh, Pa.,1966. 208 pp. Illus. Paper, $6.20; cloth,$6.95. Duquesne Studies, PhilosophicalSeries, No. 21.

Political Development and SocialChange. Jason L. Finkle and Richard W.Gable, Eds. Wiley, New York, 1966. 613pp. Illus. $8.95. There are 45 papers.

Population Studies of Birds. David Lack.Oxford Univ. Press, New York, 1966.347 pp. Illus. $10.10.

SCIENCE, VOL. 154

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294

ly 50 percent of the subjects had re-

lapses after 15 and 10 days, respec-

tively, of treatment.Longer periods of treatment with tet-

racycline were evaluated in man. Pro-phylaxis with 0.5 gram of tetracyclinetwice daily for 28 days completely pre-

vented illness. The same schedule for14 days failed. Illness occurred bothduring and after a 20-day course oftetracycline treatment given every otherday. Treatment with 2 grams of tet-racycline daily, in divided doses, for15 days or longer prevented relapses,but limiting the treatment to 10 daysresulted in relapses in 42 percent ofvolunteers.

R. J. Zentner (U.S. Army Biologi-cal Laboratories) desicribed studies on

toxic effects of oxygen on aerosolizedand on lyophilized bacteria. He re-

ported on the threshold concentrationof oxygen toxicity and suggested thatthe lethal effect is caused by dehydra-tion of the bacteria.M. T. Hatch (Naval Biological Lab-

oratory) described the effect of an-

other type of stress, namely, shifts inrelative humidity, on airborne bacteria.The studies show that changes in rel-ative humidity influence the survivalof airborne S. marcescens and P. pestis.There was no indication of which ratesof changes in humidity were mostlethal. Hatch stressed the physiologicalrather than the physicochemical na-

ture of this effect.Experimental airborne transmission

of several viral, fungal, and bacterialdiseases was discussed. W. S. Miller(U.S. Army Biological Laboratories)described studies on the infectivity ofVenezuelan equine encephalomyelitis(VEE) virus for pigeons by the res-

piratory route. He reported that thisvirus can infect an avian host throughthe lower respiratory tract but thatmarked differences exist among species.Subcutaneous injection produces a dis-ease indistinguishable from the diseaseproduced by the respiratory route.Treatment of pigeons with a combina-tion of Casa-terramycin and Hep Zideor with Casa-terramycin alone for 2weeks prior to exposure to the VEEaerosols reduced resistance to respira-tory challenge. In his comments, W.S. Gochenour (Walter Reed Army In-stitute for Research) stressed the sig-nificance of the observations of the re-

sistance of pigeons to infection whenexposed to low concentrations of VEEvirus, which can accumulate to a largedose over a long period of time (3hours).

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SCIENCE, VOL. 154

Relativity is Dead is a radicalcritique on relativity theoriesand is a bold confrontationwith those members of thecommunity who regard rela-tivity theories valid. Illustratedwith charts and diagrams,clothbound, 160 pgs.-$7.50.Library of Congress Cat. CardNo. 66-28690.

Calif. residents please add 4% sales tax

Key Research CorporationBox 100, Yorba Linda, Calif. 92686

Report from

Found: A rapid route

to the shortest path

The critical feature of Shen Lin'smethod is its speed; it makes manygood approximations in a reason-able time and selects the best.To make one approximation, the

computer chooses a "starting path"at random. It removes three linksof this path (thus breaking it intothree sections - see figures) andconnects the sections differently tosee if a shorter path results. If not,it systematically removes othercombinations of three links in theoriginal random path, until all com-binations have been tried. But,whenever such a reconnection doesproduce a shorter path, it takesthis as a new starting path, and be-gins the series of breaks again. One"approximation" is completedwhen no further improvement re-sults from such breaking andreconnection.

In the same way -beginningeach time with a new and different"'starting path" - many additionalapproximations are found. Theyusually have some path sections incommon; it simplifies the problemto assume that these are part ofthe absolute minimum path. So,they are routinely incorporated in-to every new starting path and nolonger broken. This speeds com-putation and the time that's savedis used to find even more approxi-mations.

In general, using a high-speeddigital computer, 100 approxima-tions take about 0.75n3 millisec-onds (n=number of points). Fora typical 40-point problem, experi-ments indicate that about one outof 16 approximations will be theactual minimum solution; for 60points, about one out of 64. So.if we find 300 approximations in a60-point problem (roughly eightminutes on a computer) there isa high probability that one of theseis the shortest possible.

Start with a random path...

Break it into three sections...

Reconnect them differently.

What is the shortest path througha number of points, touching eachjust once and ending at the start-ing point? This "traveling sales-man problem" is important inmany areas of modern businessand technology, where "shortestpath" may really mean the leasthook-up wire, travel time, ortransmission power.

It might seem that the problemcould be solved by measuring allpaths and taking the shortest but,even with a computer, this is acolossal task. At a million pathsper second, for instance, it wouldtake several billion years tocompute and compare all pathsin a 25-point problem! Shortcutmethods have been devised, butthey are still too slow when, say,60 points are involved. In practice,approximate solutions (almost-shortest paths) are found largelythrough the educated judgmentsof engineers looking at graphs ormaps . . . or for certain limitedproblems, through special com-puter programs.Now, mathematician Shen Lin

of Bell Telephone Laboratorieshas developed a new way of get-ting good approximate solutionsto problems of up to 145 points.Because his method is fast, it ispossible to find many suchapproximations. It is then easy topick the shortest of these. Often(see left), this is the absoluteminimum. If not, it is at leastshort enough for most engineeringpurposes.

®s) Bell Telephone LaboratoriesResearch and Development Unit of the Bell Sysbte

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It tells how-in the name of science,security, and national prestige-a smallclique of private interests and governmentagencies has been misusing America'sscientific brain-power, ravishing ournatural resources, and siphoning off taxbillions-for the profit of a few, at theperil of vital national needs. $7.95

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296

P. S. Brachman (CommunicableDisease Center) presented data on ex-posure of cynomolgus monkeys tonaturally produced aerosols containingBacillus anthracis. Anthrax infectionwas observed in approximately 25 per-cent-of the exposed monkeys. The path-ological findings of mediastinal edemaand hemorrhagic lymphogenitis andnecrosis were similar to those in mon-keys exposed to experimental aerosolsof B. anthracis and also to those inhumans who developed fatal inhalationanthrax after industrial or accidentallaboratory exposures. With the low dosepresent in chronic exposure to naturalaerosols, the incubation period ap-peared to range from 5 to 17 days.There was no evidence suggesting thedevelopment of a subclinical anthraxinfection.

Epidemiology of airborne staphylo-coccal infection was reviewed by R. E.0. Williams (Wright-Fleming Instituteof Microbiology, England) and A. D.Langmuir (Communicable Disease Cen-ter). Williams suggested that the chiefway staphylococci beconie airborne isby shedding of particles of skin frompermanent or temporary carrier sites.The magnitude and the frequency ofsuch dispersal was discussed, togetherwith factors that may influence it andthe manner in which airborne staphy-lococci travel in hospitals.

Most airborne particles containingstaphylococcus range in size from 8 to18 microns in diameter, and most ofthem contain one to four viable cocci.The bulk of each particle presumablyconsists of the epithelial squame. It isdifficult to obtain conclusive evidenceof the way in which airborne bacteriagain access to the new host or on therelative importance of airborne and"contact" routes of spread. The possi-bilities of direct airborne infection ofwounds in surgical operating rooms,primary acquisition of the nasal car-rier state in newborn infants in hos-pitals, and acquisition of staphylococciin the nose in adult patients in hospi-tals were discussed. The difficulty in de-termining the relation between dose andeffect and the importance of attemptsto do so were stressed. Langmuir dis-cussed in broader terms the epidemiol-ogy and the mechanisms of transmis-sion of airborne infection.

H. M. Yamashiroya (IIT ResearchInstitute) described aerosol vaccinationwith tetanus toxoid. He was able toprotect guinea pigs with tetanus toxoidby using the respiratory route of vac-cination. Primary aerosol immunization

as well as an aerosol booster follow-ing either respiratory or subcutaneousvaccination appear to be effective pro-cedures. H. C. Bartlema (MedicalBiological Laboratory, Netherlands)achieved similar results in mice by us-ing dead cells of Bordetella pertussisas an adjuvant.

Effects of nitrogen dioxide and ozoneon resistance to respiratory infectionwere discussed by R. Ehrlich (IIT Re-search Institute) and D. L. Coffin(U.S. Public Health Service). Thework reported suggests a more sensi-tive indicator of biological effects ofselected air pollutants, as demonstratedby reduction in resistance to infection.A single 2-hour exposure to 3.5 ppmof nitrogen dioxide before or after res-piratory challenge with Klebsiella pne-umoniae significantly increased mortal-ity in mice. Continuous exposure to0.5 ppm for 3 months produced thesame effect. Mortality also increased inmice exposed to less than 0.1 ppm ofozone for 3 hours before challenge withStreptococcus sp. Similar reduced re-sistance was observed after 4 hours ofexposure to photochemical automobilesmog.The conference was cosponsored by

the U. S. Army Biological Laboratoriesand the lIT Research. Institute, underthe chairmanship of E. K Wolfe (U.S.Army Biological Laboratories), MarkLepper (University of Illinois), andRichard Ehrlich (IIT Research Insti-tute). The proceedings of the confer-ence are scheduled for publication inBacteriological Reviews.

RICHARD EHRLICHLife Sciences Research Division,liT Research Institute,Chicago, Illinois 60616

Forthcoming Events

October

28-29. Society for Scientific Study ofReligion, annual mtg., Univ. of Chicago,Chicago, Ill. (S. Z. Klausner, The Society,1200 17th St., NW, Washington, D.C.20036)

30-3. Metallurgical Soc. of AIME, fallmtg., Chicago, Ill (American Inst. ofMining, Metallurgical, and Petroleum En-gineers, 345 E. 47th St., New York, N.Y.10017)31-3. American Soc. for Metals, 48th

annual congr. and natl. metal exposition,Chicago, Ill. (The Society, Metals Park,Ohio 44073)

31-4. American Public Health Assoc.,94th annual mtg., San Francisco, Calif.(The Association, 1790 Broadway, NewYork, N.Y. 10019)

SCIENCE, VOL. 154