Windowless Low Temperature Unit for Use in Evacuated Spectrophotometers

Vaseline brand petroleum jelly. Chesebrough-Pond's Inc. New York, N. Y.

Phillips Petroleum Company , Bartlesville, Okla. Powdered polyethylene number, EMN TR-960.

Wig L Bug Amalgamator distributed by Crescent Dental Manufacturing Company, Lyons, Ill.

The 1-in. diameter bore die, about 1 in. high, was a segment cut from a 4.5-in. high mold assembly (Catalog No. 20-2111) distributed by Buehler Ltd., Evanston, Ill.

Use of short die and preheating on hot plate were suggested by S. C. Pattacini of the Perkin-Elmer Corporation, Norwalk, Conn.

Bertie J. E. and Whalley E. , J. Chem. Phys. 46, 1271 (1967).

Reagent grade CaCO₃. Identified as calcite form by x-ray diffraction and infrared spectroscopy.

The β-Ca₂P₂O₇ was prepared by igniting reagent grade CaHPO₄ at 900°C in air for 24 h. The Ca₂P₂O₇ form (β) was identified by x-ray diffraction and infrared spectroscopy.

See Jasperse J. R. Kahan A. Plendl J. N. , and Mitra S. S. , Phys. Rev. 146, 526 (1966) for discussion of wavenumber shifts of LiF, MgO, and RbI with temperature in terms of volume and other anharmonic effects; and Fowler B. O. , Inorg. Chem. 13, 207 (1974) for correlations of wavenumber shifts of apatites with volume differences caused by temperature and cation size.

A round stainless steel pipet box was used with longitudinal seam silver soldered. Ellisco, Inc., Philadelphia, Pa.