Document zbQNvKxGR6m4mBvkDqv8kv0L3

PLAINTIFF'S EXHIBIT AL-1295 Department of Industrial Hygiene HARVARD UNIVERSITY SCHOOL OF PUBLIC HEALTH 55 Shattuc\ Street 'Boston 15, tMassachusetts December 15, 1953 Mr, Thomas Bonney Aluminum Company of America Aluminum Research Laboratories Post Office Box 772 New Kens inton, Pennsylvania Dear Mr. Bonneyt In regard to your letter of December 4, which I regret the delay in answering since I have been out of town, I would like to point out that there is an article by David A. Fraser entitled "Absolute Method of Sampling and Measurement of Solid Air-Borne Particulates" in the November issue of Archives of Industrial Hygiene and Toxicology. In this particular article Fraser mentions his procedure for dissolving molecular filters. This is quite similar to a method we have used in our laboratory which was developed by Dr. Ernest Kalmus at Los Alamos Scientific Laboratory, I am sure if you write to Dr. Kalmus he will give you the details of his method which he is planning to publish in the near future. Fraser's article uses ethyl acetate but Kalmus has used acetone. If I can be of further help in this matter please let me know. Sincerely yours. LS/p1* "Ujl,Htc-S 'Leslie Silverman, Sc.D. Associate Professor of Industrial Hygiene Engineering tb -^taw*** e^t DC. 9,6277 0002