first In precision optics

LEITZ MICROSCOPEHEATING STAGE.

FOR ATURES

UP TO 10000 C.

This Leitz unit permits micro-

analysis in transmitted or reflect-

ed light and achieves tempera-

tures up to 10000 C. It is easily

attached to any microscope with

a rotating stage.

A reputation for integrity and a tradition of service have led thousands of scientific

workers to.bring their optical problems to Leitz. If you have problems in this field,

why not let us help you with them?

See your Leitz dealer and examine these

Leitz instruments soon. Write for infor-

mation.

E. LEITZ, INC., Dept. SC-12468 Fourth Avenue, New York 16, N.Y. I

Please send me the Leitz brochure.

NAME

STREET

CITY ZONE STATE._ _ - _ _ _ _ , ,_.

E. LEITZ,UINC., 468 FOURTH AVENUE, NEW YORK 16, N. V.

Distributors of the world-famous products of Ernst Leltz, Wetztar, Germany

LENSES * CAMERAS * MICROSCOPES * BINOCULARS

l145S

I

an outstanding text for college courses

Romer THE VERTEBRTE BODY

Here is one of the finest texts for a background course in comparative anat-omy. A study of the form and function of the vertebrate body is interwovenwith embryological, paleontological, histological and evolutionary material.

A number of short sections have been rewritten in this Second Edition, andthe section on limb muscles has been shortened. New illustrations have beenadded to the chapter on the skull. Two handy appendices explain vertebrateclassification and scientific terminology.

Features of The Second Edition.

1. A wealth of illustrations help the student see beyond his own observationin the laboratory.

2. Treatment is truly comparative, without overemphasis of the humanstructures.

3. Paleontological background serves as a check on the deductions and as-

sumptions made from the anatomy of living forms.4. Embryology is presented to establish an understanding of homology and

to remind the student of the time element in the stages of development.5. Histological data show the basic materials of what gross structures are

composed and offer an appreciation of the function of glands and tissues.

6. Function of the vertebrate body is included to complete the picture ofanatomy, since organs are constructed in accord with their function.

Here, then, is an ideal text for general college students and especially thoseplanning further study in any specific or related phase of biology.

By ALFRD SHERWOOD ROMER, Alexander Agassiz, Professor of Zoology, Director, Museum ofComparative Zoology, Harvard University. 644 pages, 6%"'x9¾4", 390 illustrations, some in color.$7.00. Second Edition.

W. B. SAUNDERS COMPANYWest Washington Square -Philadelphia

SCIENCE is published weekly by the AAAS 1515 Massachusetts Ave., NW, Washington 5, D.C. Entered at the Lancster, Pa., Post Office as second clamatter under the act of 3 March 1879. Annual scriptions: $.50; foreip pottage, $1; Cdian postae, 5g.

9 DECEMBER 1955 1123~----;orin osae.$1 andinpotae 5f9 DECEMBER 1955 1123

SCI NC , OL 12

:*lexylresorcinolL-Histidine HCI

i * Holocaine HCIg * Indole Acetic Acid

* Isopropyl Arterenol~~~~~~~~~~~~~~~~~~~0DI-LeucineK * MalononitrileK * m-Methoxy Phenyl Acetic Acida * Methyl Amino Aceto Catechol HCI

* 3-Methyl ThiopheneFor the rest of the Winthrop Alphabet

send for our 1955 price list.

% LABORATORIES INCL

(Formerly Winthrop-Stearns Inc.)

SPECIAL CHEMICALS DIVISION1450 Broadway, N. Y. 18

i 9_X~~~~~~~kk

LaMOTTE pH BLOCK COMPARATORThis improved LaMotte Unit

greatly facilitates simple, accurate,Hydrogen Ion Control. It is espe-cially recomniended for the use of

:*0=_ _ iindividual operators on any step ofa process where a definite pHvalue must be maintained. Evenwith highly colored or turbid solu-tions determinations can easily bemade with accuracy.The new plastic block compara-

tor is non-corrodible, moisture-re-sistant, and has more sharply de-fined color fields.

Complete with any one set of LaMlotte Permanent ColorStandards, together with a supply of the correspon(ling indi-cator solution, measuring pipette and marked test tubes.

LaMOTTE WATER SOLUBLE pH INDICATORS(Sulfon-phthalein series) pH 0.2-9.6

These products were originally developed in the LaMfottelaboratories and are of the same sul)erior quallty as the acidformn indicatois hitherto avnilaible for l11I work.They have the distinct advantage of being lnstantly soluble

in distilled water, hence are easy to convert to solution form.Use of alkali, as required in the older technic, is ellminated, andno heating is necessary.The clean quick way to prepare indicator solutions for

accurate pH work.

LaMotte Chemical Products CompanyDept. "H" Towson 4, Md.

K LETTELECTROPHOR ESISI-

C

CUSTOM MADE

TOOL FOR THE ANALYSISOF COMPLEX COLLOID SYSTEMS, AND FORTHE CONTROL OF PRODUCTION OFPURIFIED PROTEINS, ENZYMES, HORMONES

KLETT MANUFACTURING CO.179 EAST 87TH STREETNEW YORK, N. Y.

a

I1124 SCIENCE, VOL. 122

S it b tte i 3iwith Bausch & Lomb

STEREOMICROSCOPESVIVID VIEWS

You see clearly magnified images, vivid in natural 3-

dimensional detail. Your field of critical view is widerthan with any other stereomicroscope. The reason: the

finest optical system ever produced for wide-field work.

EASY TO USE

Satisfy your specific needs... assure your comfort ... withthe right model from today's most complete line. Vibra-tion-free: no image flutter, no eye-straining prism shift.

Long working distance. Smooth, easy focus. Available in

magnifications from 6.6 X to 150 X.

LONG USEFUL LIFE

Ready whenever you need it, year after year, in the lab orin the field. No double images. . . top-bottom-and-side sup-

ports lock prism in shockproof alignment-for life!

Razor-sharp, crystal-clear images, because patented seal

keeps prisms and nosepieces dustproof-for life! A

FREE! EXCLUSIVE 3-0MICRO-VISION BOOK _

See actual stereo views!

Fit exact model to spe-cific study needs withunique Selector-Chart!Write today for ManualD-15. Bausch & LombOptical Co., 64280 St.Paul St., Rochester 2, N.Y.

America's only complete optical source... from glass to finished product

SCIENCE, VOL. 1221126

Kodak reports to laboratories on:looking through the microscope with movie fllm and camera ... materials forautoradiography ... keeping tabs on tocopherol

CinephotomicrographyThat motion pictures madethrough the microscope mighthave much value both as aninvestigative technique and asan aid to scientific communica-tion and instruction doubtlessoccurred to thoughtful men inearliest nickelodeon days, ifnot before. Certainly the arthas been widely and effectivelypracticed and improved sincethen, but how many laborersm the various vineyards havehad too many other importantand more difficult matters mer-iting their attention to givethought to what cinephotomi-crography could do for them?

Therefore, with no loftiermotive than moving a littlemerchandise, it may be that bypublishing a new revision ofthe booklet, "Motion PicturesThrough the Microscope," weshall accomplish the greatergood of a seed dropped in theright place at the right time.The booklet speaks of how

to use a motion-picture camerato alter the apparent rate ofevents on a microscope stage,making them many thousand-fold faster or four times slower,as desired; of the details of

aligning camera with microscope;of illumination, exposure, colorrendition, the defeat of vibration,and a hundred other petty pointsthat distinguish exasperation fromproud achievement.A copy of "Motion Pictures Through

the Microscope" (Kodak Pamphlet N-2)is obtainable without charge from East-man Kodak Company, Sales Service Di-vision, Rochester 4, N. Y.

Cinephotomicrograph by E. J. Farris.

Artist's choiceAutoradiography is the art of ar-ranging for a radioactive substanceto take its own picture. In calling itart, we choose our word with care,for everyone who practices it hashis own problems and his own so-

lutions, which he knows are betterthan anyone else's solutions.Some prefer to bind their sub-

jects in contact with photographicplates. For them we supply KodakAutoradiographic Plates, Type A orType No-Screen. The former arechosen for fineness of grain, thelatter for high sensitivity. Both haveemulsions about 25,u thick that lo-cate #- or -y-emitters.Some want plates with emulsions

up to 200,u thick, in which paths ofindividual ,B- or a-particles are longenough to be plotted back to theirorigins. For them we supply KodakNuclear Track Plates in five differ-ent sensitivities and six differentemulsion thicknesses.Some prefer to peel the sensitive

emulsion off its base and lay itdown on the subject. For them wemake Kodak Autoradiographic Strip-ping Film, Type NTB, that comeslike this

and winds up like this,

the impermeable layer serving toprotect the emulsion and the speci-men from each other.Some who strive for best resolu-

tion of blackened areas (rather thanof individual particle tracks) want athin emulsion and are more inter-ested in how close to the specimenthey can get it than in how wellthey can separate the two. For themwe have Kodak AutoradiographicPermeable Base Stripping Film,where the emulsion is only 5,u thickand mechanically supported by 5,uof plain gelatin that provides sup-port between the peeling and themounting steps, goes on the out-side after mounting to protect the

emulsion during exposure, and ispermeable to the solutions duringprocessing.

Others find this breadth of choicetoo narrow. Only with liquid emul-sion, these brave souls plead, canthey get the radiosensitive layer ex-actly where they want it and asthick or as thin as they want it. Butwe, who have worked with liquidemulsion for 75 years, know whatdelicate, perishable, and variablestuff it is and that its handling is nowhit less important than its com-position and compounding.

Believe us, it is neater all the wayaround to solve your autoradiographicproblems with one ofthe above-italicizedplates or films, obtained from a Kodakdealer. Nevertheless, those who haveconcluded that only liquid emulsion willdo may state their cases by letter toEastman Kodak Company, SpecialProducts Sales Division, Rochester 4,N. Y., and await developments. Yes, andwe even go sofar as to offerfree reprintsofthe recent Nucleonics article, "Alpha-Particle Autoradiography with LiquidEmulsion."

996 on EOne of the services we talk about inthe bold type at the bottom of thispage is the compilation of annotatedbibliographies of vitamin E, a taskwe assume by virtue of our positionas supplier of that vitamin to thepharmaceutical and feed industries.The new Volume III, covering only'52, '53, and most of '54, abstracts996 scientific communications. It isutterly dispassionate, advancing noproposition other than that vitaminE occupies the attention of a greatmany chemical, physiological, andclinical investigators the worldaround.

The more the merrier. Dr. Norris D.Embree, Director of Research, Distilla-tion Products Industries (Division ofEastman Kodak Company), Rochester3, N. Y., is always prepared to considerrequestsfrom professionally qualified in-vestigators for experimental quantitiesof d-alpha-tocopherol or its derivatives.Ifall that is wanted is a copy of VolumeIII, his secretary will see to it.

This is one of a series of reports on the many productsand services with which the Eastman Kodak Company andits divisions are... serving laboratories everywhere

9 DECEMBER 1955 1147