At last, a book about aging that doesn't have a bunch of autumn leaves on the jacket. Betty Friedan's The Fountain of Age is the latest in a line of lucrative ''oldster'' books, which include such titles as Gail Sheehy's Silent Passage and Tracy Kidder's Old Friends. Will the now-graying generation that made Friedan's The Feminine Mystique (1963) such a huge best-seller do the same for this book? It looks likely-The Fountain of Age is at No. 10 in its third week on the list. Weeks on Fiction List
1 The Bridges Of Madison County 60 Robert James Waller, Warner, $16.95 2 Lasher Anne Rice, Knopf, $25 3 3 Without Remorse Tom Clancy, Putnam, $24.95 8 4 Sacred Clowns Tony Hillerman, HarperCollins, $23 3 5 The Golden Mean Nick Bantock, Chronicle, $17.95 5 6 Nightmares & Dreamscapes Stephen King, Viking, $27.50 1 7 The Client John Grisham, Doubleday, $23.50 31 8 Strip Tease Carl Hiaasen, Knopf, $21 7 9 Like Water For Chocolate Laura Esquivel, Doubleday, $17.50 27 10 Vanished Danielle Steel, Delacorte, $23.95 10
Nonfiction
1 Seinlanguage Jerry Seinfeld, Bantam, $19.95 6 2 Embraced By The Light Betty J. Eadie, Gold Leaf Press, $14.95 21 3 Men Are From Mars,Women Are From Venus John Gray, HarperCollins, $20 29 4 Eat More, Weigh Less Dean Ornish, M.D., HarperCollins, $22.50 16 5 Ageless Body, Timeless Mind Deepak Chopra, M.D., Harmony, $22 12 6 Women Who Run With the Wolves Clarissa Pinkola Estes, Ballantine, $20 59 7 The Hidden Life Of Dogs Elizabeth Marshall Thomas, Houghton Mifflin, $18.95 7 8 Wouldn't Take Nothing For My Journey Now Maya Angelou, Random House, $17 2 9 Stop The Insanity! Susan Powter, Simon & Schuster, $22 2 10 The Fountain of Age Betty Friedan, Simon & Schuster, $25 3
Mass-Market Paperbacks
1 The Joy Luck Club Amy Tan, Ivy, $5.99 52 2 The Tale of the Body Thief Anne Rice, Ballantine, $6.99 5 3 The Way Things Ought To Be Rush Limbaugh, Pocket Books, $6.99 5 4 The Pelican Brief John Grisham, Dell, $6.99 35 5 Dragon Tears Dean Koontz, Berkley, $6.99 6 6 Mitigating Circumstances Nancy Taylor Rosenberg, Signet, $5.99 3 7 The Secret History Donna Tartt, Ivy, $6.99 4 8 A Time To Kill John Grisham, Dell, $6.99 68 9 Congo Michael Crichton, Ballantine, $5.99 19 10 Sphere Michael Crichton, Ballantine, $5.99 15
