February 25, 1941
NEWS
EDITION
211
COME to the An nual Drug, Chemi cal, and Allied Trade Section Dinner on March 13, 1941 at the Waldorf-Astoria Hotel.
A. R. POTASIUM IODIDE
CHEMICALS ...WHAT
ARE
SILVER NITRATE
THEY?
SODIUM TUNGSTATE
The initials A.R. following a chemical name denote that it is an Analytical Reagent, a chemical of the purest grade, used primarily in analytical work. Formerly such chemicals were known as C.P. or Chemically Pure. They were usually offered without any statement of the amounts of impurities present so that the term C.P. came to be practically meaningless unless accompanied by such a statement on the label. This gave rise to the general adoption of the term "Reagent" or "Analytical Reagent" as the American Chemical Society designates them. These terms are generally understood to apply only to chemicals suitable for analytical work which have on their label a statement of the limits of impurities present. Each Mallinckrodt Analytical Reagent is scientifically made to predetermined standards of purity and such standards are clearly cited on every label. As far as possible the standards are those published by the Ameri can Chemical Society. T h e laboratories of commerce, education, research, and diagnosis throughout the world employ these and the hundreds of other Mallinckrodt Laboratory Chemicals.
ESCHKA'S MIXTURE ETHER ANHYDROUS
BARIUM CHLORIDE PRIMARY STANDARDS
M A L L I N K R O D T CHEMICAL WORKS 2nd & Mallinckrodt Sts., St. Louis. M o . CHICAGO
7 0 - 7 4 Gold St.. N e w York, Ν. Υ.
PHILADELPHIA
MONTREAL
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