V O L U M E 25, NO. 1, J A N U A R Y 1 9 5 3 49 A

INDEX TO ADVERTISERS Ainsworth & Sons, Inc., Win 14 A American Instrument Co. Inc 28 A American Platinum Works 18 A Angel & Co. Inc., H. Reeve 41 A Applied Research Laboratories 24 A Baker & Adamson Products, General Chemical Division, Allied

Chemical & Dye Corp 4th Cover Baker Chemical Co., J. Τ 2nd Cover Bausch & Lomb Optical Co 50 A Beckman Instruments, Inc 26 A Bersworth Chemical Co ISA Blakiston Co. Inc 45 A Blue-M Electric Co 43 A Brookfield Engineering Laboratories, Inc 45 A Buffalo Apparatus Corp 36 A

Central Scientific Co 29 A Chicago Apparatus Co 45 A Coleman Instruments, Inc 25 A Coors Porcelain Co 49 A Corning Glass Works 16 A

Daigger & Co., A 47 A Despatch Oven Co 30 A Distillation Products Industries..'. 13 A

Eastman Kodak Co 13 A Eberbach Corp 30 A Farrand Optical Co. Inc 27 A, 48 A Fisher Scientific Co 22 A Fish-Schurman Corp 47 A

Greiner Co., Emit 5 A

Harshaw Scientific Co 8 A

Jarrell-Ash Co 37 A

Kewaunee Mfg. Co 48 A Kimble Glass Div 11 A Klett Mfg. Co 40 A, 42 A Laboratory Construction Co 44 A Laboratory Equipment Corp 48 A La Pine & Co., Arthur S 10 A Leeds λ Northrup Co 6 A Lindberg Engineering Co. 28 A

Machlett & Son, Ε 15 A Mallinckrodt Chemical Works 31A New York Laboratory Supply Co. Inc 40 A North American Philips Co. Inc 42 A

Owens-Illinois Glass Co 11A

Parr Instrument Co 38 A

Photovolt Corp 45 A, 46 A, 49 A

Rudolph tfc Sons, O. C 17 A

Sargent & Co., Ε. Η 21 A, 44 A Schaar it Co 12 A Schleicher & Schuell Co ' 9 A Scientific Glass Apparatus Co. Inc, 19 A Southern Scientific Co. Inc 36 A Specialized Instruments Corp 39 A Thermal Svndicate, Ltd 4 A Thermo Electric Mfg. Co 44 A Thomas Co., Arthur Η 20 A Todd Scientific Co 7 A Torsion Balance Co 3rd Cover Welch Scientific Co., W. M 32 A Will Corp 36 A

DIRECTORY Laboratory Supply Center 46 A

Cargille, R. P. Wilkens-Anderson Co. Wisconsin Alumni Research Foundation

REINHOLD PUBLISHING CORPORATION Advertising Management for the

American Chemical Society Publications Merald Lue, Advertising Sales Manager, ACS Publications

330 W. 42nd St., New York 36, Ν. Υ. ADVERTISING SALES REPRESENTATIVES

James J. Sullivan, Advertising Sales Manager New York 36-BRyant 9-4430; James J. Sullivan Cleveland 14-NBC Bldg., 815 Superior Ave., N.E., PRospect 1-5583

—Rodney D. Long, Cleveland Manager, Reinhold Publishing Corp. Chicago 2—111 W. Washington St., RAndolph 6-8497; G. E. Coch­

ran, Vice-President, Reinhold Publishing Corp.; District Manager —Frederick C. Dorr

San Francisco 5—McDonald-Thompson, 625 Market St., YUkon 6-0647; Roy M. McDonald

Los Angeles 5—McDonald-Thompson, 3727 West Sixth St., Dunkirk 7-5391; Ε. Τ. Thompson

Seattle 1—McDonald-Thompson, Terminal Sales Bldg., Main 3860; Harry Abney

Dallas 5—McDonald-Thompson, 6617 Snider Plaza, Logan 6283; Richard A. Worthington

Denver 2—McDonald-Thompson, Colorado National Bank Bldg., Keystone 4669; Robert H. Heidersbach

PHOTOVOLT Densitometer for

CHROMATOGRAPHY

A photoelectric precision instrument for the rapid and convenient evaluation of strips and sheets in filter paper chromatography and paper electrophoresis

PHOTOVOLT CORP. 95 Madison Ave. New York 16, Ν. Υ.

Also Colorimeters p H Meters Fluorimeters Electronic Photometers Reflection Meters Multiplier Photometers

Interference Filters

Two new items particularly designed

for the modern laboratory

[Obtainable in a variety of sizes f rom your laboratory supply dealer

COORS PORCELAIN C O M P A N Y GOLDEN. COLORADO

^ C O O R S ^ Γ ALUMINA 1

MORTAR AND PESTLE k Catalog No. 524 ]

L MADE OF M I ^ ^ALUMINUM OXIDE ML

r ι LOOSE PLATE · TABLE TYPE

BUCHNER | STYLE \

LFUNNEL . Catalog No. 498 ^ M