P A R R Safety Shield For S o d i u m P e r o x i d e
NEW PRODUCTS
Bombs
Constructed of 3 / 1 6 " steel plate, 12" wide χ 10" deep χ 15" high with a 3 / 4 " safety glass win dow.
T h i s new enclosure provides steel plate protection against accidental explosions when firing any P a r r sodium peroxide bomb. It is recommended especially for flame ignition procedures in which t h e bomb must be heated to a high temperature to force a reaction to completion. It should also be used when ever there is reason to suspect that a sample might react violently during t h e combustion process. Ask for Specification
2150
PARR INSTRUMENT C O M P A N Y 211 Fifty-Third St., Moline. Illinois Circle No. 82 on Readers' Service Card
table model centrifuges to meet your analytical needs From the most complete line of table model centrifuges . . . four Clay-Adams models de signed for industrial and chemical laboratories . . . all are shock-mounted precision instruments engineered and manufactured to assure years of superior performance.
c-ADAMS ANALYTICAL: For micro and semimicro separations . . . accommodates six tubes (5 or 3 ml.) . . , also adaptable for 2 and 0.5 ml. tubes . . . angle-head efficiency . . . compact, portable, requires minimum table space . . . provides fixed 3,400 RPM speed.
a-AOAMS SAFEGUARD CENTRIFUGE-ANGLE AND d-ADAMS MICRO-CHEMISTRY: F o r m i c r o - a n STANDARD HEADS: A multi-purpose, basic alytic separations of organic and inorganic instrument for labs with heavy work loads precipitates . . . eight-place angle head ac . . . accommodates any one of four standard commodates 1, 0.5, and 0.25 ml. glass or or four angle heads . . . useful for all com plastic tubes . . . provides high fixed speed mon separations and special analytic pro (13,500 RPM-15,500 RCF) . . . high R C F cedures . . . holds tubes of 15 ml. or less and assures separation of particles of similar up to 50 ml. . . . dial rheostat control pro specific gravities . . . complete, automatic vides variable RPM and R C F range. stop in 60 seconds. b-ADAMS SAFETY HEAD: For all commonly performed precipitate separations . . . adaptable for micro and semi-micro anal yses . . . six-tube capacity (15 ml. or less) . . . angle head provides fast, efficient centrifugation . . . variable R P M and R C F . . . compact, light and portable.
Available from your dealer
Clay-Adams
Circle No. 45 on Readers' Service Card
130A
ANALYTICAL CHEMISTRY
New York 1 0 , Ν. Υ.
men chamber with convenient speci men-shifting mechanism, an objective lens, a projector lens, and a fluorescent viewing screen observed through 3 large windows at t h e base of t h e column, and built-in vacuum and photography sys tems. Fisher Scientific Co., 522 Fisher Bldg., Pittsburgh 19, P a . 430
A single testing pump provides an op timum sampling rate and precise vol ume control in measuring concentra tions of a variety of toxic gases and vapors. This device—available in two mod els—is designed to replace separate colorimetric type detectors formerly required for hydrocyanic acid gas, aromatic hydrocarbons, sulfur dioxide, hydrogen sulfide, chlorine, mercury vapor, nitrogen dioxide, and halogenated hydrocarbons; and spot test type detectors for lead in air, arsine, chromic acid mist, boranes, hydrogen fluoride, and unsymmetrical-dimethyl hydrazine. In addition, the new pump will sample for acetylene, carbon di oxide, ethylene, hydrazine, and pro pylene. Accessories are available for chang ing from one test to another. Univer sal Tester. Mine Safety Appliances Co., 201 N. Braddock Ave., Pittsburgh 8, Pa. 431
Glass Vacuum System A portable glass high vacuum system which delivers vacuums down t o 1 0 e m m . of Hg has a flexible design t o allow for t h e addition of reaction sec tions. Included in t h e system a r e : mechanical and mercury diffusion pumps, mercury float valves, gages for residual low pressure, a system for sep arating and measuring the properties of test substances, and means for intro ducing, storing, and removing materials from t h e system. Seals a n d stopcocks are grease-free so t h a t materials come in contact only with mercury a n d glass. Melting point, v a p o r density, vapor pressure, dissociation pressures, and re-
