V O L U M E 2 0, N O . 2, F E B R U A R Y 1 9 4 8 39 A

EMSON Made

Seamless Will not harden or crack Strong, yet soft and pliable

RUBBER T U B I N G from pure, natural Latex

φ Non-tacky φ Chemically pure φ Sterilizable without deleterious results

φ Talc free; no talc used in processing • Uniformity of determination in bore and wall thickness φ Non-blooming and non-sulphur evolving guaranteed

EMSON BLACK RUBBER TUBING BORE, Ins. 1/8 1/8 3/16 3/16 3/16 1/4 1/4 1/4 WALL, Ins. 1/32 1/16 1/16 3/32 1/8 1/16 3/32 1/8 PER FOOT .09 .12 .13 .21 .24 .16 .22 .26 BORE, Ins. 5/16 5/16 3/8 3/8 1/2 5/8 3/4 1 WALL, Ins. 1/16 3/32 1/16 3/32 1/8 1/8 1/8 1/8 PER FOOT .18 .25 .20 .30 .50 .66 .70 1.40

EMSON AMBER RUBBER TUBING BORE, Ins. 1/8 1/8 3/16 3/16 3/16 1/4 1/4 1/4 WALL, Ins. 3/64 1/16 3/64 3/32 1/8 1/16 3/32 1/8 PER FOOT .09 .10 .11 .16 .18 .12 .17 .22 BORE, Ins. 1/4 5/16 5/16 3/8 3/8 3/8 1/2 1/2 WALL, Ins. 3/16 3/32 1/8 1/16 3/32 1/8 3/32 1/8 PER FOOT .32 .18 .26 .18 .24 .29 .26 .35 Emeon rubber tubing is available in black or amber. The black tubing is is furnished in twenty-five foot lengths. AH sizes now in stock. Order today furnished in 12 foot lengths Larger sizes either twenty

packe -four :

id 48 feet to the box u; Eeet or forty-eight it

p to the half inch diameter, jet in a box. The amber

or write for free sample.

E. MACHLETT & SON ESTABLISHED 1897

LABORATORY APPARATUS · SUPPLIES · CHEMICALS 220 EAST 23RD STREET · NEW YORK 10, Ν. Υ.

GLASS A B S O R P T I O N CELLS OF FINE QUALITY

-J' '-KUtt

Sole manufacturer in the -k U n i t e d Sta tes of fused Άτ

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

Mékers of complete Electrophoresis Apparatus

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

•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 New York, N. Y.