NEW CHEMICALS
Laser Compounds Liquid lasers obtained by dissolving rare earths give penetrating coherent lights. Sodium terbium borate emits a coherent green light at very low energy input. Semi-Elements, Inc., Saxonburg Blvd., Saxonburg, Pa. 501 Laser Host Matrices Scandium, yttrium, praseodymium and gadolinium borate single crystal rods, as well as aluminum, cerium, lanthanum, neodymium, calcium, bar ium, and strontium borate matrices are now available. The range of optically transparent rare earth fluoride crystals has been extended to include scandium and yt trium, so that fluoride crystals are now available for all elements of Periodic Groups IIA and IIIA. These crystals can be supplied doped or undoped "as grown," optically fin ished to specifications in rod form up to 3 " diameter and 10" long. SemiElements, Inc., Saxonburg Blvd., Saxonburg, Pa. 502 Carbon-13 Labeled Compounds. A new listing is available which gives the chemical specifications, packaging, isotopic purity, and pricing schedules for 26 carbon-13 compounds. Included are three acid salts, eight alcohols, six hydrocarbons, two ketones, one amino acid, four inorganic salts, and several miscellaneous C 1 3 compounds. The stable labeled compounds described are used extensively in research programs involving intermediary metabolism, particularly in multiple labeling experi ments. Volk Radiochemical Co., 8360 Elmwood Ave., Skokie, 111. 503 Semi-Conductor Crystal Source Selectively doped indium antimonide for infrared and other electromagnetic detectors is available in single crystals. These crystals are vertically grown and have very low dislocation densities. They typically have electron carrier concentrations of 1014 atoms/cc. un doped and can be doped to carrier con centrations of 10 15 to 10 18 atoms/cc. Ν or Ρ type. Block Associates, Inc., 385 Putnam Ave., Cambridge 39, Mass. 504
AO Spencer ΙΟ-second Photomicrography When you use the A O Spencer Photomicrographic Camera equipped with the Polaroid® Land Camera back, permanent photographs are ready for your files in just 10 seconds. A coupled visual and photographic system lets you shoot what you see . . . quickly and effortlessly. And with the Polaroid back possible errors in exposure, illumination or focus can be corrected immediately. In addition to the Polaroid Land camera back, you have a choice of 4 other readily interchangeable camera backs; 4" χ 5" fixed back; 4" χ 5" Grafiok back; 35mm back and Bantam back (roll film). You choose the camera back and film best suited to your specific requirements. Here, the No. 682G Camera is being used with the AO Spencer Series 4 Microstar . . . an ideal combination. The built-in base illuminator provides convenient Koehler-type illumination. You select specimen area and do all preliminary focusing through binocular portion of trinocular body . . . focus critically with the telescopic eyepiece. The sturdy vertical pillar, the easily adjustable camera support, the camera back and the Microstar all combine to provide a compact unit. Perfect alignment and rigidity is assured . . . successful photomicrography becomes a "snap". Try it and see for yourself. Your AO Representative will be happy to arrange a demonstration for you.
American
Optical
COMPANY INSTRUMENT DIVISION. BUFTAIO IS. N I W TOOK
Dept. J-48 G Please send me Brochure SB 682 describing t h e e n t i r e l i n e of AO S p e n c e r P h o t o m i c r o graphic Cameras. C Please send me Brochure SB124 describing the new Microstar line. Name-
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Circle No. 17 on Readers' Service Card
VOL. 34, NO. 1 1 , OCTOBER 1962
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