A mention of flatulence might conjure up images of bratty high school boys or lowbrow comics. But one of the most eloquentand least expectedcommentators on the subject is Benjamin Franklin. The writings in Fart Proudly reveal the rogue who lived peaceably within the philosopher and statesman. Included are The Letter to a Royal Academy On Choosing a Mistress Rules on Making Oneself Disagreeable and other jibes. Franklins irrepressible wit found an outlet in perpetrating hoaxes attacking marri