Mad Hatters, Felt, and Mercury
[caption id="attachment_2497" align="alignright" width="440"] Harry S. Truman Felt Fedora Hat - Image: National Park Service[/caption] Associated with the hat making business, how do felt and mercury produce mad hatters? Felt hats have been produced from small animal pelts since about the 14th century. During the 19th century, fur was removed from the skin using camel urine. Some hatters used their own urine, instead. The active ingredient in urine was nitrogen-rich urea. Why Urine? Those who used their own urine and were being treated for syphillis produced superior felt! This was due to the mercurous chloride (HgCl) they'd taken as medicine. Urine was replaced by orange-colored mercuric nitrate Hg(NO₃)₂. [caption id="attachment_19437" align="alignright" width="240"] Tertiary syphilis. A horrible disease, generally avoidable.[/caption] Mad Hatters The vats of solution and the drying process generated…