28 A V O L U M E 19, N O . 1 2

GLASS A B S O R P T I O N CELLS . . . .

Sole manufacturer in the it Un i ted States of fused +

E l e c t r o p h o r e s i s Cells.

Makers of complete Electrophoresis Apparatus

K/ett

OF FINE QUALITY

Fused in an electric furnace with cement that is acid, alkali and solvent resistant.

Optical Flat Walls. Many stock sizes are available. Special sizes made to order.

•KLETT SCIENTIFIC PRODUCTS-KLETT-SUMMERSON PHOTOELECTRIC COLORIMETERS · COLORIMETERS· NEPHELOMETERS · FLUORIMETERS· BIO-COLORIMETERS · COMPARATORS · ELECTROPHORESIS APPARATUS · GLASS STANDARDS · GLASS CELLS ·

KLETT REAGENTS

MANUFACTURING CO., 177 East 87th Street N e w York, Ν . Y.

designed for WELCH STAINLESS STEEL ENDURING SERVICE TRIPLE BEAM TRIP-SCALE

• STAINLESS STEEL BEAMS m DURABLE CONSTRUCTION • READINGS ARE ALWAYS SHARP, BRIGHT AND CLEAR

• IMPERVIOUS TO CORROSIVE FUMES

CAPACITY: 1,610 grams

SENSITIVITY: 0.1 g.

No. 4050

Complete with two extra weights, Each $18.00

W . M . W e l c h S c i e n t i f i c C o m p a n y 1515 Sedgwick St., Dept. A Established 1880 Chicago 10, Illinois, U. S. A.

Cobalite Knife Edges Agate Bearings

Stable and Well Damped The exclusive advantages in the Welch balance will be

appreciated by all laboratory directors. Because of the use of Stainless1 Steel, it is possible to have fine sharp lines, which are easily read. Every tiny screw, rivet or nut, in this balance is of stainless steel.