te Red . a . . , . amy ee ee ee EtBldel et hi le Pa bab nt ata? METHODS Preparation of Plates Preparation of plates was the same as described in WT-616 (UWFL-33):19. Briefly, the wet or moist samples were placed on weighed 1 1/2-inch (1 5/8 inch over-all) stainless steel plates, weighed, 550°C, dried overnight at 97°-99°C, and finally reweighed. cover the plate smoothly, reweighed, ashed overnight at The ash was Slurried with alcohol to dried and affixed with a few drops of 0 5 per cent Formvarin ethylene dichloride. Storage Plates were stored on 2 1/2 x 3 1/4-inch cards perforated with ai 1/2-inch hole into which the plates fitted. The cards bearing the plates were stored in wooden boxes with tall, narrow, slotted compartments, so that 25 cards bearing plates could be in- serted in each tier, totalling 100 plates to the box. of ash to the plate, care in handling, “Firm fixation and occasional inspection of the cards for evidence of spill guarded against loss or contamination of ash. However two decay curves had to be excluded, more curve was discontinued, and one on account of loss or contamination. 4 Counting In addition to the description of counting methods given in WT-616 it may be said that a special 1 1/2-inch-thick lead shield