INDEX TO ADVERTISERS Ace Glass, Inc American Instrument Co Bausch and Lonib Optical Co Beckman Instruments, Inc Bethlehem Apparatus Co., Inc Burrell Corp
32 26 4th cover 5:25 17 24
Central Scientific Co Coleman Instruments, Inc Consolidated Engineering Corp Coors Porcelain Co Corning Glass Works
Thomas Co., Arthur H
19 39 7:28
DIRECTORY Laboratory Supply Center
44
Clark Microanalytieal Laboratory Johns-Manville Corp. LaMotte Chemical Products Co. Research Specialties Co. Wisconsin Alumni Research Foundation
2nd cover 37 31
Greiner Co., Emil
34
Warren Electronics, Inc Welch Scientific Co., W. M
14
Fisher Scientific Co Fish-Schurman Corp General Radio Co
38
TJ. S. Stoneware Co Varian Associates
43 4:22 9:17 42 36
Eastman Kodak Co
12:30
Tracerlab, Inc
6
Harshaw Scientific Co
REINHOLD PUBLISHING CORPORATION Advertising Management for the American Chemical Society Publications, Merald Lue, Advertising Sales Manager, ACS Publications 430 Park Avenue, New York 22, Ν. Υ. SALES REPRESENTATIVES David B. Hoopes Advertising Sales Manager New York 22-MUrrayhill 8-8600; David B. Hoopes; District Man agers—Charles Richards Stoddard, Jr.; Thomas N. J. Koerwer Cleveland 14-NBC Bldg., 815 Superior Ave., N.E., PRospect 1-5583; Rodney D. Long, Cleveland Manager, Reinhold Publishing Corp. Chicago 2 - 1 1 1 W. Washington St., RAndolph 6-8497; District Manager—Fritz Lee; District Manager, Southern States (Ala., Ga., Fla., Κν., Miss., Term.) H. Scott Leonard San Francisco 5—McDonald-Thompson, 625 Market St., YTJkon 6-0647; Roy M. McDonald Los Angeles 5-McDonald-Thompson, 3727 West Sixth St., Dunkirk 7-5391; Ε. Τ. Thompson Seattle 4—McDonald-Thompson, National Bldg., 1008 Western Ave., ELliott 3767; Harry Abney Houston 6—McDonald-Thompson, 3217 Montrose Blvd., LYnchburg 6711; Frank N. Vickrey Denver 2—McDonald-Thompson, Colorado National Bank Bldg., KEystone 4-4669; Robert H. Heidersbach Dallas 6-McDonald-Thompson, 5526 Dyer St., FOrest 8-5510; Ed J. Whetzel
41
International Equipment Co
27
Kimble Glass Div., Owens-Illinois Glass Co Klett Mfg. Co Laboratory Construction Co Laboratory Equipment Corp Lindberg Engineering Co Lithium Corp. of America, Inc Loomis Engineering & Mfg. Co Machlett & Son, Ε McKenna Laboratory Mettler Instrument Corp., The Motorola Communications & Electronics, Inc
3rd cover 35:42 40 37 35 46 18 33 42 37 40
Nalge Co., The National Carbon Div., Union Carbide and Carbon Corp New York Laboratory Supply Co., Inc
7 11 45
Parr Instrument Co Perkin-Elmer Corp Photovolt Corp
45 8 10 13 38
THE L A B O R A T O R Y SUPPLY CENTE CLARK MICROANALYTICAL LABORATORY Routine Analyses in one week CH, N, S, Halogen, Fluorine, Oxygen, Alkoxyl, Allcfmide, Acetyl, Terminal Methyl, etc., by specialists in organic microchemical analysis. Howard 5. Clark, Director P. O . Box 17 Urbane, III. Send
for
Brochure.
155
MICROPIPETTES Highest accuracy Most complete selection
RESEARCH SPECIALTIES CO 1148 Walnut Street
Celite 521 Celite* 5 21 is specially p r o c e s s e d to remove acid soluble c o m p o n e n t s . N e g l i g i b l e i r o n content eliminates d a r k e n i n g w h e n filtering tannin c o m p o u n d s . T h u s , Celite 521 is par t i c u l a r l y w e l l a d a p t e d t o f i l t r a t i o n of whiskey. Also highly effective in dilute sul furic acid filtration for p e r o x i d e manufac ture, and in p r o d u c t i o n of tannic acid. For samples and complete details about Celite 5 2 1 , write Johns-Manville, Box 6 0 , NewYorkl6,N.Y.InCanada,565 B < V L a k e s h o r e Rd., E., P o r t Credit, O n t . Ϊ Ι Λ I *Reg-. U. S. P a t .
44A
' W «U«NI' M f msiAHH
Berkeley 7, Celiforni;
QUANTITATIVE MINERAL } ANALYSES INCLUDING
• FOUNDATION
S O D I U M A N D FLUORINE •
Proximate analyses ·
and amino acid assays *
Vitamin
Screening
of compounds for insecticidal, fungi-
ZINCON (2-Carboxy-2'-hydroxy-5'-sulfoformazylbenzene) A new reagent for the colorimetric determi nation of Zinc and Copper by Drs. Richard M . Rush and John H. Yoe Pratt Trace Analysis Laboratory, University of Virginia Ref. Analytical Chemistry Vol. 26, 1345-1347, August 1954
pages
A new colorimetric method for Zinc and Copper utilizing the c o m p o u n d 2 - Carboxy - 2 ' - h y d r o x y - 5 ' - sulfoformazylbenzene (Zincon). B o t h ele m e n t s form a blue complex with this reagent. T h e zinc complex is stable over t h e p H range 8.5-9.5 while t h e copper compound is stable in t h e p H range 5.0-9.5. This difference in ef fect of p H permits the determination of zinc and copper in t h e presence of each other. Both complexes follow Beer's law over t h e concentration range 0.1 to 2.4 p p m . of the element. Prices:
1 gram package 5 gram package
S 2.50 11.75
cidal, and bactericidal properties PROJECT RESEARCH AND CONSULTATION
w r i t e r WISCONSIN ALUMNI « K S i . RESEARCH FOUNDATION P.O. BOX 2059-C ·
MADISON 1, WIS.
Reprint of original article available. Manufactured by LaMOTTE CHEMICAL PRODUCTS CO. Dept. A.C. Towson, Baltimore 4, Md.
Off.
ANALYTICAL
CHEMISTRY
