I’m glad someone pointed that out. Evidence of arsenic poisoning has been found at ancient sites where copper was smelted.
Sez here, as a sulfide and oxide it has been known and used since antiquity.
https://en.wikipedia.org/wiki/Arsenic#History
As an impurity it has been sneakin’ up and killin’ people for a long long time.
If memory serves, the first sculpture from platinum (or rather the four platinum metals, which are generally found together) was accomplished using arsenic to keep it pliable while it was being hand-shaped. The sculptor just had to avoid the toxic clouds that drifted off the work.
Artists, where would we be without ‘em. 😊