ANALYTICAL
4A
CHEMISTRY
C O N T E N T S , continued NOTES O N A N A L Y T I C A L PROCEDURES
For Your Every Stirring Need
Waco "GEARED POWER" No loss of torque . . . at the speeds you need! Fully enclosed, non-sparking, fan cooled . . . you may expect T E N years' service! INDUSTRIAL LABORATORIES such « DuPont de Nemours, General Electric, Abbott Laboratories . . . hundreds of Universities . . . use the NEW W A C O Power Stirrer! 7292AC10 NEW W A C O POWER STIRRER, for 110 volts, A . C . only. Shafts H inch diameter, one 300 R.P.M. and the other 600 R.P.M. Each, $23.75. Chuck No. 7292AC10 at $1.25
BALANCED PADDLE-STIRRERS
Estimation of Cholesterol and Triterpenols In Unsaponlfiable Fraction of Wool Wax Heinz Duewell
1548
Siloxene as Chemiluminescent Indicator in Chromate Titration for Determination of Lead Frederic Kenny and R. B. Kurtz
1550
Estimating O i l Yield of Lean O i l Shale Κ. Ε. Stanfield
1 552
Quantitative Determination of 1,2-Gfycols in Mixtures E. A . Adelberg
1553
Titration of N-Carboxy-alpha-amino Acid Anhydrides in Nonaqueous Solvents Arieh Berger, Michael Sela, and Ephraim KatchalsJd
1554
Evaporation Error in Volume Fractionation Chromatography Charles Mader^nd George Mader, Jr.
1556
Electrolytic Determination of Copper with Isolated Anode D. G. Foster
1557
Distillation of Micro Quantities of Iodine G . H. Ellis and G. D. Duncan
1558
Reproducibility of Measurements Made on Cary Spectrometer and Its Log-Density Attachment . . . . J. L. Forstner and L. B. Rogers
1560
Use of Tangent Intercept to Determine Average Speed of Sedimentation" W. P. Reid
1562
Determination of Aldonic Acids in Alkaline Media J. V . Karabinos, A . T. Ballun, and R. L. McBeth
1563
Co ul ο metric Titration of p-MethylaminophenoI Sulfate and Hydroquinone by Cerium(IV) N . H . Furman and R. N . Adams
1564
Chromatographic Separation and Identification of Photographic Developers J. H. Panned and J. E. LuValle
1566
Spectrophotometry Determination of Glycerol as Sodium-Cupri-Glycerol Complex Frank Spagnolo
1566
Determination of Small Amounts of Niobium and Tantalum Using Radioisotope Tracer Technique
. . .
1 568
T. F. Boyd and Michael Galan XXVIth International Congress of Industrial Chemistry
1 574
Section of Analytical Chemistry, International Union
1 575
Society of Public Analysts
1 576
Correction
1573
CRYSTALLOGRAPHY D A T A Erythromycin Hydroiodide Hydrate
1571
H . A . Rose CORRESPONDENCE
1572
BOOK REVIEWS
1572
THE ANALYST'S CALENDAR
1576
AIDS FOR THE ANALYST Simple Circuit for Adapting Thermocouple Recorders to Measure Voltage in High-Resistance Circuits . • F. T. Gucker, Jr., and A . H. Peterson Universal Apparatus for Continuous Extraction of Aqueous Solution with Solvents More Dense Than Water D. C. Iffland
* Easily inserted in Flak * Balanced . . never whip
Modified Hershberg-Wolf Extractor
* Stainless Steel
1 577 1577 1578
Erich Heftmann and D. F. Johnson
Our new WACO BalancedPaddle Stirrers are easily inserted in the neck of the flask . . . never whip so your glass set ups are safe!
11 A
INSTRUMENTATION
17 A
R. H. Mu'ller
All made with 300 mm. χ 6 mm. shaft . . . different lengths. For all popular sizes of flasks used in the laboratory. No. 7298AC10. W A C O Balanced Paddle Stirrers. Shaft 6 mm. χ 300 mm. to fit %" or V i s * chuck. In boxes of 3 paddles. Blade 20 χ 50 mm.— S2.S5
20 χ 75 mm.—$2.40 20 χ 100 mm.—$2.55
Laboratory Supplies and Equipment
WlLKENS-ANDERSON CO. 4525 W . Division SI.
THE ANALYST'S C O L U M N
Chicago 5 1 , III.
NEW PRODUCTS
39 A
MANUFACTURERS' LITERATURE
48 A
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