,.:. ...:...:.......-.. .... ... .:..:.... .....

Not in a class b!J themselves 3FModel 18 Oven

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Model 19Vacuum

Model 6 Incubator

Moderately priced Thelco ovens andincubators rate highest in threefold thrift.

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Call your dealer today for any immedi

or write for Thelco Catalog #331

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recision Sclentific Compangiate need# 3739 West Cortland Street Chicago 47

I-AI S S

for_BIOLOGICAILrPROCEDURES

"VITAMIN-FREE"CASEIN HYDROLYSATE

An acid hydrolysate of a 10% solution of Vita-min Test Casein GBI. Vitamins are removedby several carbon treatments. When suitablysupplemented, it will support excellent growthof organisms employed in microbiologicalprocedures.

Ready-to-use, laboratory pre-tested GBI "Vita-min Free" Casein Hydrolysate is in convenientsterilized liquid form for USP and otherstandard assays, for B-Complex vitamins,amnino acids and bacterial nutrition studies.

Immediate shipment (acid or enzymatic hy-drolysate) as follows:

GBI "VITAMIN-FREE"CASEIN HYDROLYSATE

100 nil. serum bottle.$1.40 ea.I dloz. bottles $15.00 doz. $1.25 ea.

12 doz. bottles-$14.40 doz. $1.20 ea.

500 ml. serum bottle ........ .. S6.25 ea.

Save time and money with this i lhandy reference book for biologi-cal, microbiological, biochemical and_bacteriological research supplies.

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GENERAL 60 Laboratory ParkBIOCHEMICALS, INC. Chagrin Falls, Ohio

For Thorough Washing= _ of Laboratory Glassware

NONm-TOXICFOR

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Used by Leading Laboratoriesand Hospitals

WRITE FOR COMPLETE INFORMATION

I ILI :. ix..:.. UI.F;U EI.Ifl0

29 OCTOBER 1954

Carworth Farms, Inc.Laboratory animals and laboratory reagents

First in unifornmity

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For further informatlon and price listplease write:

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YOUR ad here reaches over 32,000 foremost scientistsin the leading educational institutions, industriallaboratories, and research foundations in the U. S.and 76 foreign countries - at a very low cost

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For PROOFS on display ads, copy must reach SCIENCE 4weeks before date of issue (Friday of every week).

|||||||||||||||||||||POSITIONS WANTED ||||[||||||||1||11Bacteriologist, Ph.D., 38, family; pathogenic, immunology, sani-tary chemicals; research, development; some teaching, virology,supervisory experience. Box 261, SCIENCE. 10/29

(a) Bacteriologist, Ph.D.; two years, charge of laboratory, stateboard of health; six years, bacteriologist, federal governmentagency; seeks research appointment. (b) Parasitologist, Ph.D.; andM.P.H.; well trained tropical medicine, mycology, virology; tenyears experience parasitology; also qualified administration. Wood-ward Medical Personnel Bureau, 185 North Wabash, Chicago. X

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Yeast Geneticist, Ph.D., 3 2 years post-doctoral research experi-ence, publications, desires position in university, brewery or otherfermentation industries. Married. Box 262, SCIENCE. 11/5

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(a) Physician, preferably internist, to join staff of clinical Investi-gation, large company; East. (b) Pharmacologist, psychiatric re-search program; university medical school, West. (c) Clinicalbacteriologist, Ph.D. or Master's; association group of patholo-gists; large city, medical center, East. (d) Biochemist wellqualified protein chemistry to direct small group in biochemistrysection; opportunity to become head of chemical research depart-ment; activities concerned principally with research directedtoward new products; minimum four years' experience in pharma-ceutical field required; West. (e) Bacteriologist; Ph.D., experi-enced in production and diagnostic reagents; duties principallyproduction; $6-$10,000; Chicago. S10-5 Medical Bureau (BurneiceLarson, Director), Palmolive Building, Chicago. X

Research Chemist and Assistant Chemist. One opening for researchchemist with Ph.D. preferably in biochemistry for tissue culturework with protein-amino acid metabolism in cancer. Three addi-tional openings for assistant chemists with B.S. are available inthe following areas of work.-( 1) tissue culture (2) Warburgstudies (3) organ culture. In reply, please include industrial andacademic experience, pertinent information, and a recent personalphotograph. The Samuel Roberts Noble Foundation, Inc., Labora-tory Research Division, Box 870, Ardmore, Oklahoma. X

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Singl Insertion $19.50 per inch7 times in 1 year 17.50 per inch13 times In 1 year 16.00 per Inch26 times In I year 14.00 per inch52 times in 1 year 12.50 per inch

For PROOFS on diplay ads, copy must reach SCIENCE 4weeks before date of issue (Friday of every week).

|BOOKS AND MAGAZINES IIIill!iIlAIIIIIIRIYour sets and files of scientific journalsare needed by our library and institutional customers. Please sendus lists and description of periodical files you are willing to sellat high market prices. Write Dept. A3S, J. S. CANNER, INC.

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A.4NTED TO PURCHASE . . . Sets and runs, foreign

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E

29 OCTOBER 1954

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QUALITY. AMINO ACIDSand other products you need arelisled in our catalogue. Send for outN E W - S U P P L E M E N T

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(THIS is the EXACT SIZE RECTANGLE LOVINSTRU.,ET.on the Field Finder containingover 50POO lines and lndicia. No 201-050-150They form a simple, non-marking Micr-Slidedevice for the microscopist to re-locate fields of Interest In a FIELD FINDERslide-mourtted specimen. Otheradvantages: Superb precision- LOVINS ENGINEERINGwith lnterchangeability; non-des-tructive; used by substitution.) COMPANY

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Check these important features offeredby the new RECO Model F1200:

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'I-

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& k IntroducLngfrTfTHE AG NO. 73 LABORATORY MICROSCOPE

I,Students Learn Quickly

Even the student who has never used a

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t; actual subject-matter less to operationinstructions!

Single AdjustmentHere's the secret a single coarse-fine

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features include: "Spring-loaded" focusingadj ustment mechanism to protect slidesfrom damage and a 5 aperture discdiaphragm that "clicks" into numerically-identified positions. Lower-positionedcontrol knobs and stage, as well as overalllower instrument height, mean greaterworking comfort.

New LookThe No. 73's streamlined, uncluttered

appearance will please the young student.Even the specially-designed lOX and 43Xobjectives, color-marked for easy identifi-cation, feature a new bullet-shape! Avail-able with mirror or an attached substageilluminator.Price

No. 73S Microscope, with lOX and 43Xobjectives, lOX eyepiece, just $109.00 ea.

In lots of five or more, only 98.10 ea.

American

,0ptica1Instrument Division * Buffalo 15, New York

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