Hatters, who used large amounts of felt, were often exposed to mercury vapours over long periods of time, leading to the expression "Mad as a hatter".
Hence the expression, "Mad as a hatter". Hatters, who used large amounts of felt, were often exposed to mercury vapours over long periods of time.
Hatters, who used large amounts of felt, were often exposed to mercury vapours over long periods of time. Hence the expression, "Mad as a hatter".
Hatters, who used large amounts of felt, were often exposed to mercury vapours over long periods of time. Hence the expression, "Mad as a hatter".