8. Poisonous Eyelash Dyes
Back when Queen Elizabeth I was in power, it was common for the beauty fads to mimic the Lady Regency's own tastes. So since she had red hair, most of the women (and some men) in the high court tried to mimic that same color. They would dye their hair, and would even tint their eyelashes red to get her same look. However, the way they would tint those lashes was dangerous - they often times used poisonous berries (because it gave the deepest dye) or opted for  vermilion - which was a red dye that used mercury. Tragedy would ensue. 

Image found on Pinterest here.