THE MARTINI by Barnaby Conrad III (Chronicle: $24.95; 132 pp.) "I like to have a Martini/Two at the very most--/After three I'm under the table,/After four I'm under my host." So wrote Dorothy Parker in a nostalgic moment, and there are many nostalgic moments included in this volume. In fact, it may as well come in a leather travel trunk, stamped with LONDON, ALGIERS, TOKYO, ROME. As we have come to understand the effects of some drugs, it seems the martini accentuates certain personality traits in its devotees: wit, lavish gestures and sophisticated conversation with a twist of irony. Apparently you start drinking like the hunchback of Notre Dame and you end up a cross between E. B. White, James Bond, Ernest Hemingway, Marlene Dietrich, David Niven, Ogden Nash, Dorothy Parker and the Prince of Wales. (Even Prozac can't do this for you.) The first martini appears in literature ("The Bar-Tender's Guide" by "Professor" Jerry Thomas) in 1865, apparently inspired by a thirsty gold miner in San Francisco, on his way to the town of Martinez, who stopped in a bar owned by Professor Thomas. While this anecdote may or may not be true (like so many in this wonderful book) all the ingredients are there: Thirst, inspiration and the promise of gold.