Induction Heating's Most Trusted and Creative Craftsmen Since 1926 H I G H F R E Q U E N C Y INDUCTION HEATING UNITS ⢠B R A Z I N G · S O L D E R I N G f 0 f · H E A T T R E A T I N G ⢠B O M B A R D I N G ⢠M E L T I N G ⢠Z O N E R E F I N I N G ⢠C R Y S T A L G R O W I N G ⢠P L A S M A T O R C H ELECTRONIC TUBE GENERATORS Kilocycle Frequency Units Megacycle Frequency Units Dual Frequency Units and ⢠SPARK GAP CONVERTERS LEPEL ACCESSORY EQUIPMENT Work Tables * Automatic Turntables · Roto Heating and Quenching Units · Water Recirculating Systems · Remote Control Operating Units * Change-Over Switches · Bell Jar Fixtures · Zone Refining, Crystal Growing and Plasma Torch Equipment. FREE A P P L I C A T I O N E N G I N E E R I N G SERVICEâOur engineers w i l l process y o u r w o r k s a m p l e s a n d s u b m i t recommendat ions . WRITE FOR LEPEL C A T A L O G / _ _ _ _ _ / HIGH FREQUENCY ^ E f S e i m LABORATORIES, INC. 55th ST. & 37th AVE, WOODSIDE 77, N. Y.C. CHICAGO OFFICE: 6246 WEST NORTH AVENUE NEW PRODUCTS Serological Dry Bath The SERO BLOCK bath provides fully adjustable, precisely controlled dry heat for test tubes and for serum and blood collecting tubes. I t is ad- justable to any desired temperature from ambient to 60° C , offers precise temperature control within 0.4° C , and heats up quickly. Each model is suited for certain specified tests which include agglutination, RH anti-body, pro- thrombin, Coombs, streptolycin titers and cold agglutination, cross-matching of blood, VDRL, heterophile inactiva- tions, alkaline and acid phosphotase, transaminase, lactic dehydrogenase, and serum lipase. Precision Scientific Co., 3737 West Cortland St., Chicago 47, IU. 414 The "pour pointer" shown is not only accurate to 3° F. or better and repeats to 1° F., but also is completely auto- matic. It operates continuously with- out attention while performing an un- interrupted series of test cycles. The instrument detects the change of the sample from the liquid to the con- gealed state; the sample is not frozen. The thermocouple signal from the in- strument provides direct readout with- out recorder off-set or correlation curves. Precision Scientific Develop- ment Co., 3737 West Cortland St., Chicago 47, III. 415 Zero-suppressor The Fisher zero-suppressor gives any 1-millivolt recorder a 10-millivolt range with no loss in sensitivity. It subtracts a precisely-measured voltage from the input signal. The pen then shows the difference between the total signal and the reading on the suppressor dial. This has 9 equal 1-millivolt steps, so that the range of a 1-millivolt recorder can be extended up to 10 millivolts. Fisher Scientific Co., 300 Fisher Build- ing, Pittsburgh 19, Pa. 416 Circle No. 57 on Readers' Service Card 1 3 8 A · ANALYTICAL CHEMISTRY Coors offers a complete range of casseroles, dishes, capsules and plates for laboratory evaporat ion. These pieces have been created to match the exacting requirements of work- ing chemists who require especially high qual i ty, uni formity and rel iabi l i ty. Standard items include f lat bottomed dishes, such as t h e #160 c a p s u l e s , #182 c a s s e r o l e s , # 4 3 1 and #470 dishes. A wide variety of shallow, curved bottom dishes are also available. These include the #430 regular evaporation d i s h e s , #170 c a p s u l e s , #180, # 1 8 1 , #190 casseroles, and the #440 and #450 dishes. For dry organic precipitates by evaporation and a b s o r p t i o n , t he #760 porous p la te is offered. A complete selection of Coors lab- oratory evaporation equipment is immediate- ly available through your laboratory dealer. INSIST THAT YOUR LABORATORY PORCELAIN WARE CARRY THIS MARK OF DEPENDABILITY COORS U.S.A. COORS PORCELAIN COMPANY, GOLDEN. COLORADO Circle No. 33 on Readers' Service Card : Laboratory Evaporation