CONTRIBUTED ARTICLES Determination o f Higher Aliphatic Aldehydes in Presence of Ketones and Fatty Acids
1676
Estimation o f Moisture and W a t e r o f Crystallization by Azeotropic Distillation
1 694
Simcha Harel a n d A l o n Talmi
L. D. Metcalfe a n d A . A . Schmitz
Densities and Refractive Indices for Glycol-Water Solutions. . .Triethylene Glycol, Dipropylene Glycol, and Hexylene Glycol
Fluorometric Determination of Chlortetracycline 1 678
. .
1 697
D. H. Feldman, H. S. Kelsey, a n d J . C. Cavagnol
Tsu-Tao Chiao and A . R. Thompson Squalane:
Chloric Acid Method for Determining Protein-Bound Iodine by Use of lodine-131
1681
K. J . Sax and F. H. Stress
1700
Reaction Kinetics in Differential Thermal Analysis . .
A Standard .
.
.
1702
H. E. Kissinger
J. F. G o o d w i n , R. B. H a h n , a n d A . J . Boyle
Automatic Recording Buret Titrimetric Determination of Sulfamic Acid
. . . .
1 684
1706
Saul Gordon a n d Clement Campbell
C. L. Whitman
Titration of Nitroaromatic Amines as Acids
1685
Modified Zirconium-Eriochrome Cyanine R Determina tion of Fluoride L. L. Thatcher
1 709
Microdetermination of Hippuric Acid in Urine . . .
1712
J. S. Fritz, A . J . M o y e , a n d M . J . Richard
High Frequency Titration of Lead
1 688
H. C. Elliott, Jr.
D. T. Sawyer a n d P. S. Farrington
Spot Tests Based on Nencki Synthesis of Rhodanine Voltammetry at Controlled Current.. .Automatic Recording at Solid Electrodes
(Rhodanic Acid)
.
.
.
Fritz Feigl a n d Vicente Gentil
1715
1 690 Correction
R. N . A d a m s and J . O. Voorhies
1716
RECIPROCATING SHAKER-BATHS
P O L A R AD]
Precise T e m p e r a t u r e Control Under Varying Conditions Of Agitation A n d Aeration
ROTATING CYLINDER VISCOMETER
Model
RW655
with
capacity
of
16—500
Erienmeyer
flasks is illus
trated. Series RW150
for measuring initial viscosity without extrapolation in studies of polymers, proteins and macromolecules
in smaller
available
models.
FEATURES: •
Operates at shear stress well below molecular deformation level
•
Electrostatic restoring torque, providing essentially a frictionless suspension which eliminates the usual problems associated with torsion wires.
•
Allows precise studies of Newtonian and non-Newtonian liquids.
•
Designed for quick disassembly of cylinder and float to change liquids.
•
Shear rates down to 0.2 sec-1 easily obtainable by use of simple gear changer and calibrated gear chart.
Scientific Instruments
Division
POLARAD ELECTRONICS
CORPORATION
• T e m p e r a t u r e r a n g e ambient t o 1 0 0 ° C ; accuracy within ± ' Λ ° C . (Coils f o r cooling w a t e r optional) • Speed r a n g e — 7 5 t o 2 0 0 cycles per minute, continuously v a r i a b l e • Adjustible stroke, Vi ", 1 " , 1 Vl ". • Interchangeable platforms hold Erlenmeyer flasks, tests tube or can b e a d a p t e d f o r other types o f glassware. U N C O N D I T I O N A L ONE YEAR Write
NEW
f o r Bulletin
BRUNSWICK SCIENTIFIC C O .
P R E C I S I O N
f.
Ο.
GUARANTEE
RW65-A
Β Ο Χ 6 0 6
Î A B O R A l O R Y
·
NEW
A P P A R A T U S
HUNSWICK,
43-20 34th Street, Long Island City 1, Ν. Υ. · EXeter 2-4500 Circle No. 6 A-1 on Readers' Service Card, page 83 A
6 A
·
ANALYTICAL CHEMISTRY
Circle No. 6 A-2 on Readers' Service Card, page 83 A
N.
J.
