1900 The Analyst  
THE ANALYST. 137 APPARATUS. R. Scholl. (Chem. Zeit., 1900, xxiv., 15.)-This consists of a rubber cap or plate with a central hole or short flexible sleeve to admit the pestle-stem, and a flange to fit air-tight round the upper edge of the mortar. The flange is made of considerable width, so that the cover is raised somewhat above the top of the mortar, thus leaving more space for the movements of the pestle. The cover is equally useful in grinding hygroscopic materials, or such as are brittle
more » ... ch as are brittle or possess an unpleasant odour.
doi:10.1039/an9002500137 fatcat:6zmds5yq7vbsxivxgsn36q26qu