SCIENCENEW SERIES FRIDAY, SEPTEMBER 23, 1938 SUBSCRIPTION, $6.00VOL. 88, No. 2282 S 1 =INGLE COPIES,=15

International Centrifuges

International Centrifugeswith their many excellentfeatures offer the best pos-sible solution to the vari-ous problems normallymet with in industrial,educational and hospitallaboratories.

Ruggedness of construc-tion is a characteristicwith all International Cen-trifuges.

A complete catalog of In-

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Entered a s second-class miiatter Jutly 18, 1923, at the Post Office at Larncaster, Pa., under the let of March 3, 1879.

2 SCIENCE-ADVERTISEMENTS2282

AnAmerican-MadeGiemsa Stain,

using American dyesand American solvents

Continued satisfied patronage en-courages us in our efforts in intro-ducing our GIEMSA STAIN madeafter the original method describedby Giemsa in Deutsche med. Wochen-schrift, No. 31, p. 1026, 1905.

We are supplying American scien-tists with an efficient stain marketedat a price that is reasonable by virtueof neither excessive cost of customduty fees nor high priced unfavorableforeign exchange:

Fifty grams for $2.00

Gradwohl Laboratories3514 Lucas Avenue, St. Louis, Missouri

I INDICATORSThe Coleman & Bell Company

manufacture a complete list of in-dicators including all of the com-mon indicators used in analyticaland biological work, the hydrogen-ion indicators recommended bySorensen and Clark & Lubs, and inaddition many rare indicators suit-

X able for special work. These indi-cators are available in both thedry form and in solution, ready touse. Certain indicators are offeredin the form of Test Papers in vialscontaining 100 strips, and in sheets08"xI ".

Catalogue ot Laboratory Reagents upon Request

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RECENT STUDIES INPHARMACOLOGY

Vol. 1:5 EMERSON, G. A.; KLYZA, S.J.; PHATAK, N. M.; LEAKE,C. D. Notes on the Pharmaco-logical Action of Dinitrophenyl-morphine. 25 cents

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Vol. 1:7 EMERSON, G. A.; PHIATAK, N.M. Blood-Sugar Response ofHabituated Rabbits to Incre-ments in Dosage of Morphine,Dihydromorphinone, and Dini-trophenylmorphine. 25 centsShall we send you the

complete list of this series?

UNIVERSITY OF CALIFORNIA PRESSBERKELEY, CALIFORNIA

NATIONAL RESEARCH COUNCILOTTAWA, ONTARIO

Applications are invited to fill a tempo-rary vacancy under the Radio ResearchCommittee, to assist in the Radio Sectionof the National Research Laboratories, tomaintaini staiidards of radio frequency, todevise apparatus and methods for carryinigout precision measurements, and alliedduties.The salary will be $1,75.00 per month and the

appointnient will be for a period of six months,commencing in October.

Applicants must be gradtuates of a university ofrecognized standing with at least M.Sc. degree, orequivalent standard of education, in Physics, En-gineering Physics, Radio or Electrical Engineeriiig.Candidates must be skilled in high frequency teeh-nique. Preference will be given British Subjects.

Applications should be addressed to the Secre-tary, Radio Research Committee, National Re-search Council, Ottawa, and should contain astatement of name, age, nationality, and a briefaccount of education and experience.

SCIENCE-ADVERTISEMENTS VoL. 88, No. 22822

SEPTEMBER 23, 1938 SCIENCE-ADVERTISEMENTS

Above Left-Thomson-Jeffrey Micro-tome for wood se.ctionin~gor general botanical work.

1Below Left-Minot Precision Microtomefor delicate work of thehighest character.

Above Right-Minot Automatic RotaryMicrotome with a patentedortho tilting knife holder.Blelow Right-Implroved Clinical Micro-

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WHEN SECTIONING REQUIREMENTSARE EXACTING CHOOSE A B&L

MICROTOMEB & L Microtomes are designed and constructed to meet the most exacting section-ing requirements, routine or unusual. In the number of models available the needsof every type and size of laboratory have been considered. Types obtainable rangefrom the simple Hand Microtomes to Precision Microtomes for rapid serial section-ing. Each, however, represents the utmost in accuracy, convenience and speed inits class, and is built to give the most satisfactory service over a long period of time.For complete description of all B & L Microtomes and Accessories, send for B & LCatalog D-16. Bausch & Lomb Optical Co., 642 St. Paul Street, Rochester, N. Y.

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SCIENCE-ADVERTISEMENTS VOL. 88, No. 2282

UNUSUAL FLEXIBILITY - - -- - - GREATER ECONOMY

EMPIRE LAB-AIDMICRO-SLIDE CABINET

Provides for the filing of every size micro-slide (both for visible andnon-visible filing) as well as for lantern slides and index cards. Pro-viding a sectional filing system, you may purchase individual unitsas needed. Costs as low as 1 3 of a cent per slide for non-visiblefiling and as low as I cent per slide for visible filing.

Takes up but little space-makes every inch countMaximum of utility-taking but a minimum of wall and floor space.In an area 19" x 19", 24,000 slides (3 x 1) can be visibly filed. Eachdrawer holds 400 3 x 1 slides visibly filed. A section of 3 drawerswill hold 1,200 3 x 1 slides.EMPIRE LAB-All) MICRO-SLIDE UNIT (Patented), consisting ofmetal cabinet with olive green finish, outside measurements 19" x19" x 5%" with 3 drawers and any assortment of necessary $1ninserts. Price complete . . . . . . . . 19

Other prices upon request-Sped<al discounts of 5% in lots of 5 units; 10% in lots of 10 units;

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NEW AD1)ITIONS'Cat. No. 1873-lDrawer for filing of Paraffin Blocks.Cat. No. 187:3-nolder for 3 Slides (see illustration right) $13.550 perthouisand holders only. Each drawer will hold approximately 350

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LAMOTTE MORGANSOIL TESTING

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AMERICAN INSTRUMENT CO.8010-8020 Georgia Ave. Silver Spring, Md.

INTERNATIONALREFRIGERATED CENTRIFUGEComplete witli its own refrigerating unit, asillustrated above, the refrigerated centrifugehas shown definite, practical and tinme savitigadvantages in every field of usefulness in tileIndustrial and Research Laboratories. With itsolid and liquid plhases can be separated atrigidly controlled temperatures from 320 to80°F. Tropical climate or seasonal charngeshave no effect on its operation. It obviatesthe need of using rapid hiigh power filtration.Alcohol, ether or other volatile substances canbe used with safety in this centrifuge.

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SEPTEMBER 23, 1938 SCIENCE-ADVERTISEMENTS

INSTITIJTE FOR MATHEMIATICAL ANDSTATISTICAL RtESEARACH

53 West 42nd Street New York, N. Y.The Institute specializes in the application of mathemati

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A Growing Field-Refrigerated Centrifugation

Many widely different fields of usefulness havebeen opened to scientific laboratories by com-bining refrigeration with the centrifuge.In any process in which filtration is slow andin which it is necessary to avoid bacterialcontamination and the innumlerable changes,fermentative or otherwise, accompanying arise in temperature, the problemn of clarifica-tion and separation is conlpletely solved by aRefrigerated Centrifuge.

I

6 SLE C AD E TSE E T Vo- 88 No 2282

FACULTY MEMBERS AT MEDICAL SCHOOLSrecommend

Personal ownership of aLEITZ

B I N O C U L A R f

MODEL "LMB-S-1o0"by each student

1. Reliablehospitalandlaboratorysupplyfirms at all medical centers are prepared tosupply the Leitz Microscopes to medicalstudents.

2.At all medical schools where studentslare requested to purchase their personalmicroscope through the college, Leitz Mi-croscopes can readily be obtained.3. Entire classes of medical students atmany medical schools will be uniformlyequipped with Leitz Microscopes this fall.4. Medical students can begin their stud-ies by adopting a high standard of accom-plishment, this through the selection of aLeitz Microscope.

5. "On every occasion when a Leitz Microscope is selected,the purchaser considers quality as the important factor inmaking his choice."Microscope Model "LMB-S-10" fully equipped for medicalstudent use with Built-on Mechanical Stage, rack and pinionsubstage with divisible condenser N.A.1.20 (for regularwork and darkfield illumination), attached iris diaphragm,triple dust-proof nosepiece, divisible objective 16mm-32mm(5X-10X), 4mm (45X), and oil immersion 2mm (90X),paired oculars 6X and 1OX.In Polished Wood Cabinet . . . . . . $235.00In Student Carrying Case . . . . . . . 237.00

Write for Pamphlet No. 1251-A

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6 SCIENCF,ADVERTISEMENTS VoL. 88, No. 2282

Harnwell-PRINCIPLES OF ELECTRICITY ANDELECTROMAGNETISM

By GAYLORD P. HARNWELL, University of Pennsylvania. International Series in Physics. 614pages, 6 x 9. $5.00

A thoroughly modern text designed for advanced undergraduate or graduate instruction in electricityand magnetism. The emphasis is upon the experimental and scientific rather than the mathematicalor engineering aspects of the subject. Vector notation is used and a unification is achieved by theconsistent use of absolute practical units and the electromagnetic approach to magnetism.

Groggins-UNIT PROCESSES IN ORGANIC SYNTHESIS.New second edition.

Edited by P. H. GROGGINS, U. S. Department of Agriculture. Chemical Engineering Series.740 pages, 6 x 9. $6.00

As before, this textbook presents in a systematic manner the principles and problems of the more im-portant and well-defined reactions in organic synthesis as they are found in actual practice. Everychapter has been revised and brought into line with curreilt developments.

Maximov-PLANT PHYSIOLOGY. New second edition.By N. A. MAXIMOV, University of Saratov, U.S.S.R. Edited by R. B. HARVEY, University ofMinnesota, and A. E. MURNEEK, University of Missouri. McGraw-Hill Publications in theBotanical Sciences. 505 pages, 6 x 9. $4.50

This well-known book has been completely rearranged, revised, and brought up to date. Much newmaterial has been added. The present text is not merely a translation, but a new book based on atranslation of the fifth Russian edition.

Allen-AN INTRODUCTION TO AMERICAN FORESTRYBY SHIRLEY W. ALLEN, University of Michigan. American Forestry Series. 393 pages,6x9. $3.50

This general text for beginning classes offers a clear, accurate, readable, and well-illustrated treat-ment of forests and how they are made to sustain their services to mankind. Recent developmentsand examples of practice, both public and private, are emphasized, and particular attention is givento forest protection, policy, and administration. The approach is new in its integration of the sci-entific, technological, industrial, and social aspects of the forest.

. Send for copies on approval

McGRAW-HILL BOOK COMPANY, INC.330 West 42nd Street, New York, N. Y.

SEPTEMBER 23, 1938 SCIENCE-ADVERTISEMENTS 7

Aldwych House, London, W.C.2

SEPTEMBER 23, 1938 SCIENCE-ADVERTISEMENTS 9

'a

These distinguished Hoeber Ibooks may be ordered onapproval. The form at theright is provided for your Iconvenience. I-I

- - - - - ORDER FORM - - - -

Paul B. Hoeber, Inc.Medical Book Department, HARPER & BROTHERS49 EAST 33rd STREET, NEW YORK, N. Y.

Please send me: ...............................................

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IMPORTANT HOEBER PUBLICATIONSACarrel & Lindbergh

THE CULTURE OF ORGANSCARREL AND LINDBERGH present to biologists and physicians a new method that renders possible the cultivationin vitro of entire organs and anatomical regions extirpated from animals or human beings. The range of its appli-cation extends from anatomy, embryology, physiology, and especially endocrinology, to biological chemistry, phar-macology and pathology. This clearly expressed and complete account of one of the most important scientificadvances of our day should be in every scientist's bookshelf. Illustrated, $4.50

Downey (EDITOR)

HANDBOOK OF HEMATOLOGYThis monumental four-volume work by thirty-eight of the world's outstanding authorities fills the need for acomprehensive definitive treatise on the blood. Illustrations, so important in this field, have not been spared,fifteen hundred being included with fifty superb color plates. Because of its wide scope, appealing to patholo-gists, anatomists, zoologists, physiologists, histologists and immunologists as well as all medical clinicians, the HAND-BOOK OF HEMATOLOGY should be available in all scientific libraries. A fully descriptive sixteen page booklet will besent free on request to those seriously interested in the work. Four volumes, profusely illustrated, $85.00

McClung (EDITOR)

MICROSCOPICAL TECHNIQUEDesigned for workers in both plant and animal tissue, the second edition of this book is an essential part of everylaboratory's equipment and an ideal text for courses in the subject. Among the new material presented in thenew expanded edition are directions for free hand manipulation of living material, methods for staining boutonsterminaux, an account of the fused quartz method of illuminating living structure, a description of fluorescentmicroscopy and so on. The book has been written by thirty-four distinguished authorities and edited by C. E.McCLUNG, Professor of Zoology, University of Pennsylvania. Waterproof binding, illustrated, $8.00

Parker

METHODS OF TISSUE CULTUREHere is the first comprehensive, authoritative guide to the techniques, procedures and applications of tissue culture.It contains a description of basic procedures developed and used in Carrel's laboratory at the Rockefeller Instituteas well as an extensive review of the literature and examples of how the method may be used to advantage in almostevery field of experimental biology as well as the study of tumors and viruses. The author's qualifications for pre-senting the material are unique, for, aside from his own contributions to the subject, he has spent three years inHarrison's laboratory at Yale, two years with Fischer in Berlin and eight years with Carrel in New York. Besidesits usefulness as a practical manual the logical presentation of the material makes it fill the need for a laboratorytextbook in the subject. With a foreword by ALEXIS CARREL. Illustrated, $5.00

Gesell

BIOGRAPHIES OF CHILD DEVELOPMENTFrom the well-known Yale Clinic of Child Development comes this unique study by ARNOLD GESELL and his asso-

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SEPTEMBER 23, 1938 SCIENCE-AD'VERTISEMENTS 9