Brain Droppings

You know the ''comic as author'' genre has spun out of control when Gallagher is talking about a book of his own. No joke. Still, few funnymen are better suited for the page than George Carlin, the language-obsessed cynic. And he doesn't disappoint. In this rambling book of observations, Brain Droppings, Carlin spills vinegar on everything from cliches (meteoric rise makes no sense, as meteors don't rise) to body piercing (he proposes kids should get their lungs pierced). In fact, at 60, Carlin seems more delightfully adolescent and nihilistic than ever. His motto, he declares in the intro, is ''F--- hope.'' Later, he makes similar points: ''F--- Al Jolson,'' ''F--- sports,'' and ''F--- soccer moms.'' Golly, that's fun reading. A-