Masquerade balls were extended into costumed public festivities in Italy during the 16th century Renaissance (Italian, maschera). They were generally elaborate dances held for members of the upper classes, and were particularly popular in Venice. They have been associated with the tradition of the Venetian Carnival.
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.