Product Capsules Colorimeters. 64-page manual, "Cole man Tools for Science," available. Includes information on filter instru ment with wide choice of sample sizes: 9 curvette sizes and types; sample volumes from 10 ml. to .007 ml. Color imeter offers 4 ways to measure : optical density and % transmittance from either galvanometer or potentiometer scales. Coleman Instruments, Inc., Maywood, 111. 56A Crucibles, Platinum. Complete infor mation available on new polygon-shaped platinum crucible cited as retaining its shape indefinitely and being available with or- without reinforced rim, in all standard sizes. The flat sides of the polygon extend only part way down; the balance is circular. Bottom is flat. Baker & Co., Inc., 113 Astor St., Newark 5, N. J. 12A Densitometers. Bulletin available on densitometer for partition chromatog raphy and paper electrophoresis. Photovolt Corp., 95 Madison Ave., X. Y. 16, Ν. Υ. 39Α-2 Dipolemeter. Data sheet available on instrument for dipole-moment measure ments of liquids and gases. The capaci tance of the test cell and sample can be determined to an accuracy of ± 2 X 10~5 for liquids, and ± 1 Χ ΙΟ"6 for gases. Arka Imports, 754 Ladera St., Pasadena, Calif. 57A-1 Electrophoresis-DifTusion
FOR YOUR
MERCURY •
PUREST
•
B E S T in P a c k a g i n g
•
PROMPT
INSTRUMENTS
Quality Delivery
O u r I N S T R U M E N T M E R C U R Y is PURE to better than one part per ten million (Certificate of Analysis with every o r d e r ) . Our TRIPLE DISTILLED Q U A L I T Y MERCURY meets A.C.S, N.F., and A.D.A. specifications. Both are PACKAGED in handy "squeeze" bottle with dispensing tip. SHIPPED from stock in 1, 6, 16 and 65-lb. polyethylene bottles. Write for Bulletin I. M. and current prices on new Mercury. MERCURY CLEANING SERVICE
Send for Form 1155 giving details of our Cleaning Service. We make it a simple matter to have your contami nated mercury cleaned and returned to you as either Instrument or Triple Dis tilled Quality.
BA
BETHLEHEM Apparatus Company, Inc. HELLERTOWN, PENNSYLVANIA
For further information, circle number 59 A-1 on Readers' Service Card, page 71 A
Units.
Circle 59A-1 for complete information on instruments cited as having multiple optical systems arranged for rapid and efficient use, an optimum of automatic controls, and a single-unit construction. Also available is complete information on company's ultracentrifuges (circle 59A-2). Spinco Div. Beckman Instru ments, Inc., Belmont 7, Calif. 59A-1,2 Evaporating
Dishes,
Porcelain.
Catalog available. Includes informa tion on evaporating dishes suitable for a \'ariety of laboratory uses. Large range of sizes available, some with black glaze interior. Coors Porcelain Co., Golden, Colo. 47A-1 Evaporators. Folder providing detailed information available on unit that dis tills 100 ml. of aqueous solution at 55° C. in 10 to 15 minutes under the reduced pressure of an ordinary water aspirator. Suitable for batch or con tinuous operation, "Rotovap" is com pletely automatic and provides safe, rapid and efficient evaporation of either dilute or concentrated solutions, com pany states. E. Machlett & Son, 220 E. 23rd St., N. Y. 10, Ν. Υ. 24Α-1
OHAUS
ffoJ^ûJeigh
She m o s t m o d e r n p a c k a g e of w e i g h t sets ever offered
WEIGHT SETS
Every l a b can now have their weights in a shrink-proof, reinforced plastic, hinge-covered case. M o d e r n , functional design affords sure, easy grasping. AVAILABLE IN BUREAU OF STANDARDS CLASSES C - Q - P
V O L U M E 2 8, NO. 9 , S E P T E M B E R 1 9 5 6
for complete information tarife for FREE bulletin
OHAUS SCALE
CORPORATION
lOSO COMMERCE AVE. UNION, NEW JERSEY
For further information, circle number 59 A-2 on Readers' Service Card, page 71 A
59 A
