The recently published "Fusion Methods in Chemical
Microscopy",
by Walter C. McCrone (Interscience Publishers, Inc., 1957), contains detailed techniques for the use of the McCrone Micro Cold Stage.
/ W l - M c C R O N E MICRO COLD STAGE For micro fusion studies over M I C R O COLD STAGE (Micro Melting Point A p p a r a tus), Thomas-McCrone Thermometer Reading M o d e l .
With built-in heating unit to provide close temper ature control within a working range of —100° C to +70°C when using dried, cooled nitrogen gas. Based on the design described by Walter C. McCrone and S. M. O'Bradovic in Analytical Chemistry, Vol. 28, No. 6 (June, 1956) p. 1038. Supplements the Kofler Micro Hot Stage as a low tsmperature micro melting point apparatus. Also suitable for determination of characteristics of the polymorphic trans formations. Made of phenolic plastic and furnished with two nickel plated, adjustable feet for attachment to the stage of a microscope in place of stage clips. Can be used on a micro scope with polarized light or phase accessories. The bevelled cut-out in the top of the stage takes a standard lOx objeci ive. Construction has been simplified for convenient insertion of sample and to permit reproducible placement of iritercha ageable low temperature thermometers. Heating is by means of a Pyrex brand E-C Radiant Glass plate. Voltage on the heating unit should not exceed 80 volts and a Variable Transformer, with mechanical stop to limit output voltage within the range 0 to 80 volts, is included with the Stage. The manipulator rod for seeding, moving the glass test plate and similar operations, is inserted into the working chamber through a ball joint. Thermometers are inserted from the side and protected by means of a transparent plastic guard tube. In use, a stream of inert gas, precooled to a temperature below the expected melting point, is passed over the sample and escapes from the stage through a small annular sipace around the objective. Practically all moisture is removed from the gas stream in a simple Cooling Device which is offered as an accessory. Condensation of moisture and pos sible icing of the objective is minimized by this positive flow of moisture free gas. The gas stream in the chamber is heated by the E-C radiant slide.
the range
—100°C to
+70°C
6892-6. Micro Cold Stage (Micro Melting Point Apparatus), ThomasMcCrone Thermometer Reading Model, as above described, with plastic manipulator rod with Stainless steel needle; two thermometers, range — 70°C to + 7 0 ° C and — 100°C to + 3 0 ° C , respectively, in 1° divisions; transparent plastic thermometer guard; extra E-C Radiant Glass heating unit for replacement; 'Λ gross glass test plates; '/z oz. Red Label micro cover glasses. No. 1, 12 mm square; Powerstat voltage transformer; and 6-ft. cord and plug. For use on 11 5 volts, 60 cycles, a.c. only 179.25 6893-F. Cooling Device, for precooling the gas stream. Consisting of Dewar Flask, 4300 ml capacity, for use with dry ice and acetone, two-piece plastic cover, copper cooling coil with pressure coupling for attachment to Cold Stage, 8 inches of Silicone rubber tubing, V£-inch bore χ 'Λ-inch wall; and Thermometer, range —95°C to + 3 0 ° in 1° divisions 53.75 6893-N. "Fusion Methods in Chemical Microscopy", by Walter C. McCrone, f/nfersc/ence Publishers, Inc., 1957). Contains approximately 328 pages, 158 illustrations and 23 tables, and includes techniques for both the Thomas-McCrone Cold Stage and the Kofler Hot Stage. . .6.75
Complete assembly, showing Micro Cold Stage in position on microscope stage and connected with Transformer, Cooling Device for gas stream, and supply of gas
ARTHUR H. THOMAS COMPANY
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VINE ST. AT 3 R D · PHILADELPHIA, PA. Far further information, circle numbers 54 A-1, 94A-2, 54 A-3 on Readers' Service Card, page 77 A 54 A
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ANALYTICAL CHEMISTRY
