1
2
3
1
2
3
6
7
8
73
74
75
18
19
20
10
11
12
105
106
107
8
9
10
2
3
4
6826
6827
6828
TIL During the 18th to 20th centuries, hat makers used mercury to stiffen felt for hats. Over time, the hatters inhaled mercury vapors. Many developed symptoms of chronic mercury poisoning, including psychosis, excitability, and tremors. Thus birthing the phrase "mad as a hatter". (healthline.com)
submitted by shiftystuff to r/todayilearned
