The Laboratory. Vol. 30, No. 1 con tains articles on chemical warfare, measurement of average particle size, metallographic apparatus, temperature control, and chromatographic column packings. Fisher Scientific Co., 713 Forbes Ave., Pittsburgh 19, Pa. Norelco Reporter. Vol. IX, No. 1 (1962) features articles on sample preparation for x-ray diffraction powder camera, illustrative applications of the stereomicrography technique, and a new compact neutron source. Philips Electronic Instruments, 750 S. Fulton Ave., Mount Vernon, Ν. Υ. CA Bulletin. This June issue contains information on standard solution con centrates, magnetic stirrers, balances, and laboratory frame assemblies. Chi cago Apparatus Co., 1735 N. Ashland Ave., Chicago 22, 111. Laboratory Spotlight. Some 50 items including pH meters, balances, auto matic titrators, photomicroscopes, centrifuges, and torsion balances are in cluded in this issue. No. 23. Harshaw Scientific, Division of The Harshaw Chemical Co., 1945 E. 97th St., Cleve land 6, Ohio. Scientific Apparatus. Vol. 1, No. 1 of a new publication, "Scientific Appara tus," is now available. The 16-page issue illustrates and describes impor tant new developments, new items from manufacturers for whom they are dis tributors, and general utility items for chemical and biological laboratories. Arthur H. Thomas Co., Inc., Vine St. at Third, P. O. Box 779, Philadelphia 5, Pa. J-A Newsletter. Performance char acteristics and typical applications of all three spectroscopic instruments are among the items in the No. 12 issue of the J-A Newsletter. Other items in clude descriptions of two models of 5-meter stigmatic flame grating spectro graphs, new spectrograph standards, x-ray monochromator, and electron af finity chromatography. No. 12 JarrellAsh Co., 26 Farwell St., Newtonville 60, Mass. The Perkin-Elmer Instrument News.
The 12-page issue of the quarterly pub lication features articles on the use of the far-infrared region in solid state electronic transitions, a new technique to polish halide cell windows, and studies of structural assignments from optical rotatory dispersion spectra. Vol. 13, No. 2. The Perkin-Elmer Corp., Norwalk, Conn.
THE CARE AND FEEDING OF V E R Y C L E A N V A C U U M S ( A n o b j e c t l e s s o n in w h a t t o d o w i t h stray organic molecules) Oil is fine on the bearings of a car. Or after baby's bath. Oil is not fine on the walls of your vacuum system. If you're not using a Varian Vaclon® all-electronic pump, you've probably got oil in your system. In thin-film evaporation or semi conductor work, this can be trouble some. Oily systems produce grubby vacuums. Grubby vacuums produce thin films that don't come up to par, or semiconductors that behave in mysterious ways. If at all. Now, ion-getter pumps are dandy for avoiding oil contamination. They remove gases by reconstituting them into stable solids. There aren't any stray organic molecules wandering around in your vacuum system. Hard to say that for oil-diffusion pumps. Varian Vaclon pumps can pump down to the 5 χ 10-'° mm Hg range. They're extra-reliable; fail-safe design
VACUUM PRODUCTS DIVISION
means no messy clean-up jobs in the event of vacuum or power failure. We can provide all sorts of excel lent vacuum hardware. High thru-put pumps. Miniature pumps with speeds of 0.2 litres/second. Monster pumps with speeds of 10,000 litres/second. Catalog-item systems, for a bewilder ing variety of applications. We've been told we sound smugly confident when we talk about Vaclon pumps. That, we'll admit. We're so confident that we guarantee to re place your Vaclon pump if it doesn't perform exactly the way we say it will. Or your money back. We ask only that you design your vacuum system after heeding the thoughtful advice of our wise old vacuum scientists. We could tell you more, but we've done it better (and with formulae) in a brochure. Write for your copy.
V A R I A N PALO
ALTO
associates Λ,
CALIFORNIA
Circle No. 109 on Readers' Service Card VOL. 34, NO. 8, JULY 1962
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