... and depression. Scientific American (ISSN 003 6-8 733), published monthly by Scientific American, Inc., 415 Madison Avenue, New York, N.Y. 1001 7-1 111. Copyright © 1993 by Scientific American, Inc. ... Scientific American, Box 3187, Harlan, Iowa 51537. Reprints available: write Reprint Department, Scientific American, Inc., 415 Madison Avenue, New York, N.Y. 1001 7-1 111, or fax : ( 212) 35 5-0 408.Copyright ... Financial OÛcer, R. Vincent Bar-ger; Vice Presidents: Jonathan Piel, John J.Moeling, Jr.8 SCIENTIFIC AMERICAN May 1993 PRINTED IN U.S.A.Copyright 1993 Scientific American, Inc.Mathematics in...