FEBRUARY 5, 1943 SCIENCE-ADVERTISEMENTS 9

McGraw-Hill AnnouncesTHE METALLURGY AND METALLURGICAL

ENGINEERING SERIESUnder the Consulting Editorship ofROBERT FRANKLIN MEHL

Head, Department of Metallurgical Engineering, Director Metals Research LaboratoryCarnegie Institute of Technology

The new Metallurgy and Metallurgical -Engineering Series aims to provide for the practising metal-lurgical engineer, the research worker, and the student a series of authoritative books and texts onmodern practice and on the scientific fundamentals in the field of metallurgy.Metallurgy has advanced enormously since the days when Henry Marion Hume's classic,, Metallog-raphy of Steel and Cast Iron, was published under the McGraw-Hill imprint. The great develop-ment and great extension of the field of metallurgy has taxed the engineer and the student, in partbecause of the dearth of standard books in which the fundamentals of practice and of science aretreated in competent fashion. McGraw-Hill offers this new series as an aid to those engaged in thegreat task of adapting metals to the needs of society.

Just PublishedStructure and Properties of Alloys

By R. M. BRICK and ARTHUR PHILLIPS, Yale Univer-sity. 227 pages, 6 x 9, 149 illustrations. $2.50

Seeks to establish the correlation among alloy phase dia-grams, micro-structures, and properties. Especial atten-tion has been directed to the effect of industrial practicesin casting, working, and heat treating alloys on the appli-cation of, or departure from, theoretical principles. Afeature of the book is the inclusion of 136 photomicro-graphs, with full descriptions of their origins, illustratingnormal and abnormal structures of the most standardalloys.

The Principles of MetallographicLaboratory Practice

By GEORGE L. KEHL, Columbia University. Secondedition. 453 pages, 6 x 9, 191 illustrations. $4.00

Deals with the principles of physical metallurgy, especiallyas they underlie effective laboratory practice. The authorcovers apparatus and procedures for preparation of speci-mens, examination, testing, etc., giving detailed instruc-tions for carrying out a number of important manipula-tions, and emphasizing the theory and fundamentalsnecessary to an intelligent application of the variousoperations.

Books in PressMetallurgical Problems

By ALLISON BuTTs, Lehigh University. Approximately500 pages

A revision of the author's A Textbook of Metallurgical

Problems. It presents practical problems designed toaccompany courses in metallurgy, and outlines and givesexamples of the methods used in calculation, with tablessupplying the necessary data. The book has been broughtup to date with respect both to metallurgical practice andto the chemical and physical data as tabulated and usedin the text.

The Physics of MetalsBy FREDERICK SEITZ, Carnegie Institute of Technology.Approximately 300 pages

Gives an entirely non-mathematical treatment of the de-velopments of the physics of metals that have taken placein the past fifteen years. The topics treated include thestructure of metals, factors determining the stability ofalloys, the theory of plasticity of metals, diffusion inmetals, the theory of iron-carbon alloys, the electrontheory of solids and its applications to cohesion, mag-netism, and conductivity.

The Structure of Metals. Crystallo-graphic Principles, Techniques,and Data

By CHARLES S. BARRETT, Carnegie Institute .of Tech-nology. Approximately 500 pages

A text and reference book covering structures, properties,and theories of metals and alloys and the crystallographictechniques of physical metallurgy. It includes extensivereviews of preferred orientations and directional prop-erties, effects of cold work and annealing, plastic defor-mation, dislocation theory, age hardening, transforma-tions, alloy structures, superlattices, electron diffraction,and stress measurement by x-rays.

Send for copies on approval

McGRAW-HILL BOOK COMPANY, INC.330 West 42nd Street, New York, N. Y. Aldwych House, London, W.C.2

SCIENCE-SUPPLEMENT

SCIENCE NEWSScience Service, Washington, D. C.

INFLUENCE OF SUNSPOTS ONWEATHER

VAGUE correlations between sunspots and the weatherprobably exist, but the weather is affeeted so much byother factors that the influence of sunspots is insignifi-cant. This is reported in a lecture at Stanford Univer-sity by Dr. Seth B. Nicholson, of the Mt. Wilson Obser-vatory, after a quarter of a century devoted primarily tosolar research concerning the much-discussed question ofwhether the weather can be predicted from sunspotactivity.

Dr. Nicholson conceded, however, that conditions uponthe sun are not exactly the same when there are manyspots as when there are few, and that any change in thesun's radiation will certainly be reflected some way in theweather. Ever since the great astronomer, Sir WilliamHersehel, in 1800 tried to correlate the price of wheatwith the number of sunspots, not only astronomers, butmeteorologists, botanists and bankers, both professionaland amateur, have been trying to find such correlationswithout much success. Invariably they arrive at the sameconclusion as Hersehel-more data are needed in order toprove them. This is true in spite of the fact that boththe quantity and quality of solar data have greatly in-creased since Herschel 's time.With regard to the possibility of making short range

predictions for particular regions from individual sun-spots, Dr. Nicholson was even more emphatic.

'He said:

"Certainly it is foolish to think that an individual sun-spot can in any way produce definite changes in theweather at any particular locality on the earth."

SNOWDON'T grumble if there 's a lot of snow in your neigh-

borhood. Be thankful instead. Snow is one of the im-portant ingredients of victory. Not, perhaps, in thedirect sense that it is in Russia, but our American snowis a great help toward the goal none the less.Snow on the ground now means bread and milk on the

table before next winter's snow begins to fall. For win-ter wheat and other fall-sown grains depend on snow nowfor protection against the cold and drying winds of win-ter, and they will depend on the water from the thaw formost of their growth in spring. If they get a good startin late March and during April, a very little rain in Maywill suffice to make the crop that will be harvested in July.Similarly, snow makes the early hay crop and the springpastures, on which our milk supply depends to a largeextent.Snow is a major source of the water that few of us

ever even think about, except weather men and agricul-tural scientists; what is known as subsoil water. Thisis the moisture well below plow level, on which trees andbushes depend, and the deeper-reaching roots of maturingcrops. Corn roots, for example, go down from three tofive feet; alfalfa roots as much -as twenty. And it is thismoisture reserve that they depend on.

Water that trickles down through partly melted snowduring occasional winter warm spells is an especially goodmeans for replenishing this deeper deposit on which cropsmay draw later on. Such melt-water can not run off verywell; there is nowhere for it to go but down. It is onlywhen the snow cover melts away completely that there iscause for anxiety-the more so since the winter grainsare then left naked to possible fierce sudden freezes orhard dry winds. No Northern farmer feels easy in win-ter if he is able to see the soil in his fields.How much water it takes to make a bumper crop is

vividly brought out in a calculation recently offered byJ. B. Kincer, of the U. S. Weather Bureau. Comparingthe excess of water that fell in the abundant crop yearof 1942 with the scanty fall during the desperate droughtof 1934, he said: "If it were possible to load this excesswater on super-trains of 100 tank cars, each carrying 100tons of water, and transport them over a super-railroadat the rate of two trains a minute around the clock with-out missing a single schedule, it would require more than100 years to complete the shipment."-FRANK THONE.

HEARING AND VISION OF AMERICANFLIERS

CHANGES in plane designs to aid the hearing and visionof American combat fliers were recommended to the In-stitute of Aeronautical Sciences meeting in New York.Professor Walter R. Miles, of Yale University, statedthat "Both seeing and hearing, if accompanied by pro-longed attentive effort, especially under conditions of un-favorable plane design, are capable of contributing to pilotand air crew fatigue and loss of efficiency." Collabora-tors with Professor Miles in preparing the report wereCommander Leon D. Carson, head of the Medical ResearchSection in the Navy's Bureau of Aeronautics, and Pro-fessor Stanley S. Stevens, one of the directors of thePsycho-Acoustic Laboratory at Harvard University.

Plane gunners should be moved much nearer the aim-ing window. The position of the gunner now gives himthe same sort of vision as he would have in a tunnel, sincehis eyes are some distance away from the window. Sec-tions of gun mounting, electrical switches and othergadgets which lattice the aiming window are also a hazardto vision and life. The amount of structure in front ofgunners should be reduced. Clearing away these obstruc-tions to vision and moving the gunner nearer the windowwill " increase his angle of uninterrupted view, makevisual pursuit of his targets easier, and reduce the blind-ing effect from the flashes of his own guns."

In the cockpit, the instrument panels have too large anilluminated area. They are usually illuminated too in-tensely and with a color that disturbs night vision. Indi-rect red light was recommended by Professor Miles andhis associates as best. Discussion of vision from the cock-pit disclosed that transparent enclosures often becomediscolored with exposure to sunlight or become checkeddue to temperature changes and vibration.

10 VOL,. 97, NO. 2510

FERAY5 93SINC-D E TS M NS1

I 19.vv

NEW WILEY BOOKS,INTRODUCTION TO BIOPHYSICS

By OTTO STUHLMAN, JR., Professor of Physics, University of North Carolina.

Written for junior or senior college students who have had one year of college physics, and pref-erably a year of unified mathematics. The book offers eight chapters on the borderline prob-lems of biology and physics.

Approximately 384 pages; 6 by 9; Probable price, $.00

PATHOLOGY IN FOREST PRACTICEBy DOW V. BAXTER, Assistant Professor of Silvics and Forest Pathology, University. ofMichigan.An eminently practical treatment of the subject of forest pathology, designed to provide a workingknowledge of the conditions which cause disease and of the practical measures which can be takento reduce its incidence or its severity.

Approximately 575 pages; 6 by 9; Probable price, $4.75

ELEMENTARY QUALITATIVE ANALYSISBy BRUCE E. HARTSUCH, Associate Professor of Chemistry, Michigan State College.The subject matter of this book is suitable for use in beginning courses in qualitative analysis.The material is written in a readable and understandable style, with detailed, step-by-step solu-tions of illustrative problems. Laboratory directions are included.

Approximately 294 pages; 71 by 101; Probable price, $2.50

FOREST ECONOMICS AND FINANCEBy P. L. BUTTRICK, Consulting Forester; formerly Professor of Forest Management, Univer-sity of Georgia.A general treatment of forest economics, keyed to the capabilities of the average student. Coversthe economic and financial aspects of forestry, including considerable material on forest exploita-tion and industries, and on the economic aspects of protection, recreational and wildlife forestry.

Approximately 492 pages; 6 by 9; Probable price, $4.00

ANALYTIC GEOMETRYBy EDWARD S. SMITH, Professor of Mathematics, University of Cincinnati (absent on leave,with U. S. Army); MEYER SALKOVER, Associate Professor of Mathematics, and HOWARDK. JUSTICE, Professor of Mathematics; both at the University of Cincinnati.A new book by the authors of the well-known "Calculus." Designed to give the student accurateand fully illustrated explanations of the topics commonly taught in analytic geometry and, at thesame time, fit him for further studies in mathematics, science or engineering.

Approximately 337 pages; 6 by 9; Probable price, $.50

THE CHEMISTRY OF POWDER AND EXPLOSIVES, Volume 11By TENNEY L. DAVIS, formerly Professor of Organic Chemistry, Massachusetts Institute ofTechnology.Deals with nitric esters, smokeless powder, dynamite and other high explosives, ammonium nitrateand nitroamines, primary explosives, detonators, and primers. (Vol. I, 1941, covered propertiesof explosives, black gunpowder, pyrotechnics, and aromatic nitro compounds, $2.75.)

Approximately 298 pages; 6 by 9; Probable price, $3.00Combined volume, Probable price, $4.50

JOHN WILEY & SONS, Inc., 440 4th AVE., NEW YORK

V VT VT 77 V VT V 77 V TV VT 7 V V V V 77 TV V TV VT V 77 V V TV

FEBRUARY 5, 1943 SCIENCE-ADVERTISEMENTS 11

SCIENCE-SUPPLEMENT

Dr. Miles pointed out that "Rapid strides in develop-ment of better plastics are being made, and it should bepossible soon to mold transparent cockpit enclosures ofbetter grades of optical plastics in one piece. Surfacehardening of such molded parts is desirable. "The ears of flying personnel take even greater abuse

than their eyes. Noise from air turbulence around theplane is in some ways more disturbing than the noisefrom the propeller itself. The interior of a glider plane,for example, is a very noisy place when traveling at 150miles per hour. Conversation is difficult if not impossi-ble. Several methods were suggested for overcoming thedistracting noises of combat flying. "Judicious use ofsound treatment in the plane, conversion to high-fidelitymicrophones and earphones, and the development of acous-tic devices to shield the mouth and the ears of the per-sonnel," Professor Miles said, "will permit the aviatorto carry on in the best noises which the aeronauticalengineers are now planning to produce."

THE PHYSIOLOGICAL STRAINS OFMODERN FLYING

ENGINEER and biologist must cooperate if human beingsare to be really successful in handling the formidable fly-ing machines which aeronautical invention has given them,was emphasized by Professor D. W. Bronk, of the Uni-versity of Pennsylvania, at a lecture sponsored by thenational science honor society, Sigma Xi. The biologist,and in particular the biophysicist, has as his task thediscovery of the performance limits of the units of thehuman nervous system. The engineer must adapt hismachine to a controlling organism operating within thoselimits.As an example of these performance limits, Dr. Bronk

cited the now familiar "blackout" experienced by divebombers in pulling out of a steep, fast dive. It is knownthat the centrifugal effect of this sudden upswerve drainsthe blood away from the brain, and "blackout" results.

Basic reason for this momentary unconsciousness isoxygen starvation on the part of the brain cells. Braincells are at all times very greedy for oxygen; they neverhave more than a few seconds' supply on hand. So any-thing that cuts off fresh supplies, even for a little while,cr6ates a physiological crisis-threatens a shutdown forlack of an essential material.

Professor Bronk described some of the exceedingly deli-cate instruments used in modern physiological researchto obtain data on the needs and capacities of nerve andbrain cells. The chronic state of incipient oxygen starva-tion of the brain cells was discovered by means of amicroscopic metallic electrode than can be inserted intovarious regions of the nervous system with relatively littledamage. Differences in the minute electrical currenttransmitted tell tales of fluctuations in amount of oxygenpresent, and hence of the relative state of efficiency ofthe cell at the moment.Nerve cells can be isolated, yet kept alive, and thus

studied as single units. Thus isolated, their structurecan be analyzed by new electrical, optical and electron-microscopic methods. The electron microscope gives new

vistas into the molecular architecture of the cell. Theelectrical states tell of its internal responses to fluctua-tions in the supply of essential elements such as calciumand phosphorus, and other environmental influences.

ITEMSDIESEL engine power may soon be increased by super-

chargers similar to those now used on plane engines.Problems involved in thus increasing our power supplywas discussed at the Detroit meeting of the Society ofAutomotive Engineers. A Swedish supercharger nowbeing applied to American engines was explained in apaper prepared by Alf Lysolm, of Aktiebologet Ljung-strom, Augturbin, Sweden, and Ronald B. Smith and W.A. Wilson, of the Elliott Company, Jeanette, Pa. Sucha device now being manufactured weighs only 80 poundsand handles 400 to 500 cubic feet of air per minute.Other sizes adequate to serve the largest diesel enginescan be built, the report stated.

To protect passengers in stratosphere planes, the cabinmust be sealed airtight. Progress and difficulties encoun-tered in solving this complicated problem were reportedat the annual meeting of the Society of Automotive Engi-neers by R. L. Ellinger, of Transcontinental and WesternAir, Inc., Kansas City, Mo. The cabin must be filledwith air at proper temperature and pressure, the speakerpointed out, regardless of outside conditions and themajor problem of stopping leaks. Seals of many typesand designs are needed at points where controls pass outof the cabin. Actual planes must be used as flying testlaboratories, as simulated conditions in test chambers werenot successful.

CENTRAL and South Americans will soon be practicingsplinting, bandaging and artificial respiration on eachother, as we did last winter and spring, it appears from anannouncement made by Chairman Norman H. Davis, ofthe American Red Cross in Washington. The gray paper-covered American Red Cross first aid text-book, nowfamiliar to millions of North Americans, has been trans-lated into Spanish and Portuguese and will soon be avail-able for distribution to all Central and South Americancountries. The translations will be made by the MexicanRed Cross and the Brazilian Red Cross with the permis-sion of the American Red Cross. Previously, its distribu-tion had been limited to Mexico and Venezuela.

IF you are taking fresh yeast as a means of gettingextra vitamins into your system, boil it before you eat it.The human body apparently can extract two or threetimes as much thiamin or vitamin B1 from boiled yeastas from fresh, according to a report by Dr. Helen Parsons,of the University of Wisconsin, at the Detroit meeting ofthe American Dietetic Association. Boiling the yeast,though troublesome and likely to make it less palatable,increases the amount of two other B vitamins (riboflavinand vitamin G) the body can get from the yeast. Pro-nouncements on boiled vs. fresh yeast were based on ex-periments with ten students and with laboratory animals.

VOL. 97, No. 251012

FERAY5 93SINC-D ETS M NS1

Synopsis of ClinicalSYPHILISThe broad scope of thehave created a need fo:Volume. Necessarily, o

By JAMES KIRBY HOWLES, B.S., but Hlowles' book givesM.D., M.M.S., Professor of Derma- entire subject in brief.tology and Syphilology, and Direc-tor of the Department, Louisiana For the sake of clarityState University School of Medicine. convenience, an outline

560 pages, 121 illustrations, material. The text is2 color plates,

PRICE, about $5.00 recommendations for thiYou'll find it ideal for totary reading.

IMMUNOLOGYAmong the important revisions for the second edition of thispopular text are the addition of two new chapters-on thereticuloendothelial system and serum reaction-and the re-vision of the chapters dealing with serology of syphilis.

Throughout, standard technics are- presented, analyzed anddiscussed. References are extended to accommodate thestudent who desires to read more extensively, and definitionsare given freely.

Consider Sherwood's text for classroom or reference use.

subject of syphilis, and its incidencer such a book-as this new Synopsisextensive detail has been omitted-you a comprehensive picture of the

and conservation of space, and yourhas been followed in presenting thewell illustrated and practical in itserapy.

ext use or as a source of supplemen-

by NOBEL PIERCE SHERWOOD,Ph.D., M.D., F.A.C.P., Professor ofBacteriology, University of Kansas.Second Edition.

639 pages, 27 illustrations,7 color plates. PRICE, $6.50

.- --_ -

The C. V. Mosby Company SCI. 2/433525 Pine Blvd.St. Louis, Mo. -

Gentlemen: Send me the following book(s): ............................;

[1 Attached is my check. fl Charge my account.

Dr. ..........................................................................

Address ......................................................................

Ready Next Month

orderToday!

FEBwRUY 5, 1943 SCIENCE-ADVERTISEMENTS 13

14 SCIENCE-AD VERTL~~~~~~~~~~~~~~~~~~~~~~~~~~EMENTS VOL. 97, No. 251~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

'Ihe TECMiNISCOPEA Miultiple Microscope

U. L P!di No. 2,133,321

THE TECHNICON CO.New York

14 SCIENCE-AD -IISEALENTS VoL. 97, No. 2510

-n~5 93SINC- D E TS M N S1

BECKMAN PHOTOELECTRIC

QUARTZ SPECTROPHOTOMETERA self-contained, precision instrument with quartz prism, operating on an electronic circuit,

for the rapid measurement of percentage transmission and densityA B C D E

/ I\ 4, I

Beekman Photoelectric Quartz G H J KSpectrophotometer

A, Wavelength Scale; B, Built-in Electronic Indicating Meter; C, Slits with precision adjustment; D, LightSource; B, Compartment for two Phototubes; F, Holder for four 10 mm Absorption Cells; G, Filter Slide;

H, Compartment for Absorption Cells, J, Phototube Selector; and K, Switch for checking dark current.

QUARTZ SPECTROPHOTOMETER, Beckman Photoelectric. A self-con-tained unit with which a wide variety of researeh and control work can be conductedwith convenience, speed and precision. See Cary and Beckman, "A Quartz Photoelec-tric Spectrophotometer," Journal of the Optical Society of America, Vol. 31, No. 11(November, 1941), p. 682.lMonochromator. Autocollimating type, with 300 Electronic Indicating Meter. A built-in poten-

quartz prism of selected crystal which provides tiometer and electronic amplifier makes possiblehigh dispersion in the ultra-violet. Wavelength direct readings in percentage transmission andscale approx. 100 cm long, graduated from 200 mmu density. The switch position marked ".1" pro-to 2000 mmu, readable to 0.1 mmu in the ultra- vides a ten-fold expansion of the transmission scaleviolet and to 1.0 mmu in the red, with a scale ac- for more accurate readings on solutions below 10%curacy of 1 mmu. transmission.

Optical parts rigidly mounted in a massive heat- Light Source. A 6-volt, tungsten lamp servestreated iron block within a dust-proof steel case. for the range 320 to 1000 mmu. For the, ultra-

Slits Simultaneously and continuously adjust- violet range below 320 mmu, a small hydrogen dis-able from 0.01 to 2.0 mm by a precision mechanism. charge tube with power supply.Full scale reading with nominal band width less Sample Holders Cells and holders are availablethan 2 mmu over all but the extreme ends of the for 10, 20,.50 and 100 mm liquid lengths; also Ac-spectrum. cessories for Measuring Diffuse Reflectance.9101. Quartz Spectrophotometer, Beckman Photoelectric, Model D, Range 820 to 1000 mi crons. Consist-

ing of monochromatot with quartz prism and two slits, built-in electronic meter, 6-volt tungstenlamp in detachable housing, one each Caesium-Oxide and Blue-Sensitive phototubes, and holderwith selected set of four Corex glass absorption cells for 10 mm liquid length. With dry cellsfor operating the meter but without 6-volt storage battery as required for operating the tungstenlamp and electronic tube filaments 764.00

9101-B. Ditto, Model DUV, Range 220 to 1000 millimicrons, identical with above but with ultraviolet-sensitivephototube in place of the blue-sensitive tube and with the addition of accessories for far ultra-violet consisting of one pair of Fused Silica Absorption Cells for 10 mm liquid length, HydrogenDischarge Tube, housing for same, and a power supply unit, 110 volts, 50/60 cycles, for maintain-ing the discharge at constant intensity 1052.00

More detailed infowrmation-sent upon request

ARTHUR H. THOMAS COMPANYRETAIL-WHOLESALE-EXPORT

LABORATORY APPARATUS AND REAGENTSWEST WASHINGTON SQUARE PHI LADELPHIA, U. S. A.

Cable Address, BALANCE, Philadelphia-

1

111

TEBwAuy 5, 1943 SCIENCE-ADVERT-ISEMENTS 15

16SINEAVRIEET O.9,N.21

7he /Wi4ace FOR SCIENCE

Akn OutstandingVALUEAt $72.80

(Immediately available)

No. 61010Y MICROSCOPE, MON-OCULAR, SPENCER, is a standard sizeinstrument with standard optics, de-signed to meet the requirements of lab-oratory work in classes studying biology.The fine adjustment is the popularSpencer micrometer screw-type which,for precision and durability, is unsur-passed. The coarse adjustment is moti-vated by the diagonal rack and pinionoperating in oil grooved bearing surfaces.Two achromatic objectives of 10 and 44Xinitial magnification are provided which,

61010Y with the loX Huyghenian eyepiece, give100 and 440X magnification. The lOX

objective is separable. When the lower part is removed, the upper part withthe lOX eyepiece gives 40X magnification. The body tube is of fixed standardlength and is fitted with the unique Spencer dust-proof revolving nosepiecehaving dual-cone bearings. The diaphragm placed just beneath the stage is ofthe revolving type, the best for student use because of its sturdiness. Thestandard size concave mirror is mounted in a fork attached to an adjustable mir-ror bar. The instrument has an attractive black stain finish with chromiumplated parts ...... Price $72.80(Laboratories may purchase these under Limitation Order L144, as amended)

SCIENTIFIC INSTRUMENTS & LABORATORY APPARATUSCHICAGO BOSTON

1700 Irving Park Road, J , 79 Amherst St.,Lakeview Station Cambridge A Station

--a

16 SCIENCE-ADVERTISEMENTS VOL. 97, NO. 2510

SCIENCE-ADVERTISEMENTS 17

OUTSIDE the main gate at CorningGlass Works stands this big new Rollof Honor. On it are row after row ofnames-over 1,000 to date-from thesales force, office, laboratory, andplant personnel now serving in ourArmed Forces.Among these are names of field

representatives of the Laboratory andPharmaceutical Division. They calledon you, in the past, to render a helpfulservice, to keep you advised of thenewest developments in Corning Re-search. And they welcomed your sug-gestions or criticisms so that we

could continue to make our ware everbetter.

While they are serving as Corning'sfighting representatives at the front,we who remain are carrying on. Al.though fewer in number, our field menwill call on you as often as conditionspermit. News of Corning develop-ments in "Pyrex" brand, "Vycor"brand and "Corning" brand Labora-tory Glassware will be brought to youby mail, by printed literature and bycontinuous advertising in trade publi-cations.You, in turn, directly and through

yourlaboratory supply dealer,can helpus to help you, by your commentsand criticisms. Our "sights" have notbeen lowered. There will be no let-upin our efforts to supply you with con-stantlyimproved laboratory glassware.

P Y R E XIRANDLAB -ORATORY WARE"PYREX" oal "VYCOR" are reeid trdes-marks cod i;dacaf mmobvscure byCORNING GLASS WORKS * CORNING, NEW YORK

FEBRUARY 5. 1943

18 C E C - DV R I E E T VOL 97o.21

4.16.

.4l V'.q** 1

-4111

$

As a leader in the development of themodern Microtome, Spencer is interest-ed in furthering the effectiveness of itsuse. Extensive research has resulted ina new booklet by Oscar W. Richards,Ph. D., Research Biologist of the Spen-cer Lens Company. *We believe that thisinformation will be helpful to all usersof Microtomes.

*A COpY will be maileduapon receipt of 25 cetsin coi or stmp:s.

Spencer LENS COMPANYBUFFALO, NEW YORK

SCIENTIFIC INSTRUMENT DIVISION OFAMERICAN OPTICAL COMPANY

18- SCIENCE-AD RTISEMENTS VoL. 97, No. 2510

1A.