DRIERITE "THE VERSATILE DESICCANT"

For Drying SOLIDS-LIQUIDS-GASES

REGULAR DRIERITE A low cost, all-purpose drying agent, DRIERITE is neutral in reaction, chemically stable, constant in vol­ume, inert except toward water, in­soluble in organic liquids and re­frigerants, non-disintegrating, non-wetting, non-poisonous, non-cor­rosive, repeatedly regenerative, and non-channeling.

INDICATING DRIERITE While possessing all of the properties of regular DRIERITE, INDICAT­ING DRIERITE makes a clearly visible change from blue when dry to pink when exhausted.

Order directly from your Labora­tory Supply Dealer.

Write to us for our new 100-page book

W.A.HAMMOND DRIERITE COMPANY 120 Dayton Avenue, Xenia, Ohio

Circle No. 58 on Readers' Service Card

MANUFACTURERS' LITERATURE

Microscopes. A 12-page booklet de­scribes the various models of Brink-mann microscopes, manufactured in West Germany. Included are instru­ments for college, research, and path­ology laboratories. Brinkmann Instru­ments, Inc., 115 Cutter Mill Rd., Great Neck, Ν. Υ. 625

Hydrogenator. A single sheet de­scribes and gives the operating prin­ciples of the Brown Hydrogenator, an automatic unit which permits hydro­génation of unsaturated organic com­pounds at atmospheric pressures and temperatures. Delmar Scientific Lab­oratories, Inc., 317 Madison St., May-wood, 111. 626

Dechema Materials Tables. A pamphlet, "Dechema-Werkstoff-Ta-belle, Inhalt und Ausfuhrung," con­tains the method of compilation, pub­lication, conditions of subscription, and specimen pages of the Dechema Ma­terials Tables. The latter is a com­pilation dealing with the resistance of structural materials to 33 aggressive media, from sodium aluminate to sodium pyrosulphite. DECHEMA, 6 Frankfurt am Main 7, Postfach 7746, Germany. 627

Power Modules. A 34-page catalog describes, gives specifications, and prices a.c. and d.c. solid-state power modules. Technipower, Inc., 18 Marshall St., South Norwalk, Conn.

628

Company Periodicals Requests for copies of the following publications, catalogs, etc., should be sent directly to the address shown. Business or professional letterheads are requested.

The Laboratory. Vol. 31, No. 1. This issue contains an index to Vol. 30 of "The Laboratory." Also included are articles on the following subjects: history of writing inks, laboratory re­frigerator, mixing and grinding in the lab, oxygen sensor, a high-voltage elec­tron microscope (JEM-150), laboratory stills, Teflon ware, a sampler, and lab­oratory burners. Fisher Scientific Co., 711 Forbes Ave., Pittsburgh 19, Pa.

The Analyzer. The January issue in­cludes articles on the following sub­jects: analysis of sodium in water in the p.p.b. range, a purgeable air com­parison pycnometer, process control by GC, and the use of continuous process analysis in the production of liquefied petroleum gases. Beckman Instru­ments, Inc., Scientific and Process In­struments Div., Fullerton, Calif.

TRITIUM Labelling Services

Al though Nuc lear -Chicago has the most extensive line of tritium-labelled compounds commercially available (139 at last count), it is impossible to meet every demand of the individual tracer worker. In recognition of these special needs, we offer three types of tr i t ium labelling services for investigators who can supply the compound to be label led.

TR-1: Labelling by Catalytic Exchange in Aqueous Media

Suitable only for organic compounds stable in aqueous solutions at tempera­tures up to 120°C in the presence of a platinum catalyst.

The material (not over 1 g) and the platinum catalyst (about 200 mg) are stirred with tritiated water or 70% acetic acid (3 ml) containing not less than 100 curies for 16-20 hours under reflux. The tritiated solvent and labile trit ium are removed by treatment with water.

After removal of the catalyst, the prod­uct is supplied as a freeze-dried solid, as a liquid, or dissolved in a suitable solvent, however desired. In general, purity and specific activity are higher than from a Wilzbach irradiation, and complete purification is easier.

Standard labelling charge: $390

Purification and analysis (minimum ad­ditional charge): $560

TR-2: Irradiation with Tritium Gas— (Wilzbach method)

TR-3: Hydrogénation of Unsaturated Compounds with Tritium Gas— (reduction labelling)

(ASK FOR our Technical Data sheet describing all three services in detail. We will be glad to consult with you to arrive at the most appropriate pro­cedure for any given compound.)

„ NUC:G-3-225

n nuclear-Chicago C O R P O R A T I O N

351 Howard Avenue, Des Plaines, I l l inois Te lephone: 312 827-4456

Circle No. 87 on Readers' Service Card

VOL. 35, NO. 6, MAY 1 963 · 1 4 9 A