GEORGie WINTHROP (304 pp.)Sloan WilsonHarper & Row ($4.95).
The bookstore browser takes a second look and, by Georgie, finds that it is true: the last two letters of the first word of the title of Sloan Wilson's novel are italicized. The more than Oriental subtlety of the author's device will be recognized instantly by cryptographers, Talmudic scholars, unscramblers of step-by-step directions for assembling toy rocket launchers, and other delvers into meaning's inmost leaf. Shading his words as finely as a subdeb writing home from Miss Porter's (the prom "was marvelous but not marvelous"), Wilson makes it clear that his hero is one...