132 fine powder by hand with a mortar and pestle and approximately 1.5 gram aliquots of this subsarple were suspended in 50 milliliters absolute athanol in a two-ounce polyethylene bottle. Each bottle was shaken and allowed to stand for three minutes, at which time a suspension was pipetted from one inch below the ethanol surface and filtered through a tared 47 mm 0.45 um "i 1ipore filter and filter holder® using a vacuur filtration apparatus. Directly under the ilillipore filter was placed an absorbent pad (supplied with filters). By careful addition of the suspension a relatively uniform layer of material was deposited over the inner circular area (9.435 cm”) of the filter funnel. The filters were vacuum dried with dry air for two minutes, after which the initial absorbant filter pad was replaced with a dry one, and further dried for 5 minutes, or until a cood flow of dried air is established through ths filter. The filter was then removed and placed on a tared 2" stainless steel counting planchette. A third absorbant pad is placed over the filtered sample and the assembty is placed under a weight in a vacuum dessicator to keep the Millipcre filter flat during drying. After drying at least 18 hours, the planchette and filters were weighed® and covered with zinc sulfide screens’ which were neld tightly acainst the dried sample with saran wrap. ‘vil lipore Corporation, Bedford, Ilassachusetts 01730. oil lipore Corporation, number XXID 047 20. >The cellulose acetate filters lost a relatively constant 3.378 mg due to the 3-10 milliliters of ethanol filtered. This may be avoided by using other available Millipore filter materials. “Type AST-3, avaiiable from Wm. 3. Johnson & Assoc., Inc., Mountain Lakes, N.d.