... ancient Babylonians ( in modern - day Iraq ) recorded the use of " chew sticks ” — twigs with frayed ends to clean their teeth ... Romans bought other people's urine to clean stains from their teeth . ( The uric acid in urine actually ... Open this book anywhere, any time, any place for bite-size morsels of essential (and not-so-essential) knowledge. We have two mottos here at Portable Press: "Get smart" and "Have fun." As the publishers of the wildly popular Uncle John's Bathroom Reader series, we have twenty years' experience in translating our mottos into bestselling books, but we also know that not every reader is a bathroom reader. That's why we've created this definitive collection of bite-sized bits of knowledge that covers a wide variety of topics ranging from the seemingly ordinary to the obscure. We'll take you on a fun and fascinating trip through the essentials (and nonessentials) of history, science, geography, the arts, pop culture, language, mathematics, and more. So you can become a genius instantly! Up your