The woman who revolutionized the way Americans eat and treat food will turn 90 on August 15. That's hard to believe, but it's even harder to remember the world of food without the influence of the vibrant, vivacious Julia Child. She was our liberator, an army of one who freed us from our provincial, 1950's food mentality and allowed us to learn to cook and eat real French food, right here, right in our own kitchens. Her first foray was Mastering the Art of French Cooking written with Simone Beck and Louisette Bertholle (the first cookbook I ever owned). It appeared in 1961 and was hailed as "a masterpiece" and "the definitive work for nonprofessionals." James Beard said, "I only wish that I had written it myself." Then, just a year later, Julia went on television as The French Chef, and the rest is history delightful, delicious history. A special 40th anniversary edition of Mastering the Art of French Cooking, volume one, (Knopf, $40, 752 pages, ISBN 0375413405) was recently published with a new intro by the birthday girl, and both volumes one and two are available in paperback, as are her six other fabulous cookbooks. Sybil Pratt has been cooking up this column for many years.