The toothpick is not just among the simplest of manufactured things, Petroski explains, but one of the oldest: Grooves on fossilized teeth suggest that early hominids might have regularly applied small sticks or even blades of grass to the spaces between their teeth. With his usual flair for combining technical expertise and cultural acumen, Petroski (The Pencil) presents nearly every toothpick in the historical record. No incident seems too small to escape his notice, from the Qur'an's endorsement of using toothpicks before praying to Sherwood Anderson's death by a still-skewered martini olive. The narrative eventually closes in on Charles Forster, the entrepreneur who introduced the mass manufacture of toothpicks to Maine and created an American industry; the battle over the Forster estate led to a mildly melodramatic family squabble. Petroski occasionally offers a first-person perspective, describing the unpleasant feel of a bamboo pick or confessing that sometimes he'll resort to a mechanical pencil. Although some readers may feel he pushes the limits of the history of ordinary objects genre, there's still enough intriguing detail, even in the minute evolutions of toothpick etiquette, to keep readers engaged. Paperback. 443 pgs.