The Tooth Test – Rub the pearls lightly along the biting edge of your upper front teeth. If they feel slightly rough, sandy or gritty, it’s likely they are cultured or natural pearls because of the layers of nacre that have formed over time. If they feel smooth or glassy, they are probably imitations.
Antoine Lavoisier (lah-vwah-ZHAY), 1743-1794, introduced quantitative measurement into the study of chemistry with his discovery of the law of conservation of mass. He discovered the role of oxygen in combustion and established the principles for naming chemicals. He wrote the first modern chemistry textbook in 1789.
It is a myth that it is dangerous to wake up a sleepwalker because it may cause them a heart attack, shock, brain damage, or something else. It is not a myth that it is dangerous to wake up a sleepwalker because of the possible injury the sleepwalker may inflict upon themselves or the person waking them up.