Ancient Romans, for example, used urine and goat milk to whiten their teeth. This concoction is not as far-fetched as it might first appear. Urine, contains ammonia which is a cleaning agent found...
Hippocrates used a powder made from the skeletons of mice. Pliny the Elder used burnt eggshells, and the ancient Arabs resorted to twigs from the Arak shrub. What were they trying to do? Clean...