26 LABORATORY EQUIPMENT, PARTICULARLY FOR HANDLING CORROSIVE MATERIALS-NAMELY, ACID RECONDITIONING APPARATUS, AGITATORS, BLEACHING APPARATUS, CONCENTRATING APPARATUS, CONDENSERS, DEHYDRATING APPARATUS, DENITRATING APPARATUS, DISTILLING APPARATUS, EVAPORATORS, FILTERS, KESTNER STILLS, KETTLES, KJELDAHL DIGESTION APPARATUS, AND WET ASHING APPARATUS, AND PARTS THEREOF