Document 85r6G687kXG9Qnkn8xXRoLVeB

4* PLAINTIFF'S EXHIBIT r August 12, 1954 Dr. Robert W. Schiessler Associate Professor of Chemistry College of Chemistry and Physics Pennsylvania State University State College, Pennsylvania Dear Dr. Schiessler: Thank you for the directions for syntheses of PSC 510 and 174, which I have received in Dr. Horton*s absence. I expect to carry out those syntheses in the near future. The directions for PSC 174* which I will use to prepare PSC 559 seem clear and detailed. However, the directions for PSC 510 seem rather sketchy, and I would greatly appreciate more complete details, particularly concerning the dehydration step. Sincerely, RPT:mJg Ruth Pierle Trosset SC-API-2580