Cutting onions irritates the lachrymal glands, causing them to excrete tears. Chewing gum while cutting onions prevents tears by forcing you to breathe through your mouth. This disperses the irritant so that a significantly smaller amount reaches the lachrymal glands, preventing them from being irritated enough to release tears.
Scholars think Hernán Cortés brought the seeds in 1519 with the intent of the fruits being used ornamentally in gardens. By the 1700s, aristocrats started eating tomatoes, but they were convinced the fruits were poison because people would die after eating them. In reality, the acidity from the tomatoes brought out lead in their pewter plates, so they’d died of lead poisoning.