y popular. The haters had to brush a mercury-containing solution onto animal fur as part of the hat-making process. The hatters inevitably breathed in the mercury, a problem made worse by the poorly ventilated workshops in which they worked. They developed tremors and twitching (“hatter’s shakes”) as well as slurred speech, irritability, shyness depression, confusion, memory loss and other personality changes - all symptoms of mercury poisoning.