Martin and Kite's 2002 article warns museum professionals about the danger of handling these items due to carroting.  
A man receiving a syphilis treatment who made these things for a living supposedly came up with a way to use lower quality ingredients when he pissed into an acid mixture. Thomas Jefferson called a 1732 Act of Parliament restricting the sale and export of these things as "an instance of despotism to which no parallel can be produced in the most arbitrary ages of British history".  Martin and Kite's 2002 article warns museum professionals about the danger of handling these items due to carroting.  Designer Lilly Dache wrote a memoir titled Talking Through My [These Things]. Use of these things declined after JFK's inauguration. A world capital of making these items lends its name to the infamous (*) "Danbury Shakes".  The felt of these things often contained mercury, causing the people who made them, called milliners, to go as mad as a Lewis Carroll character.  For 10 points, a fedora is what type of object?
A man receiving a syphilis treatment who made these things for a living supposedly came up with a way to use lower quality ingredients when he pissed into an acid mixture.
hats or [felt hats; or top hats; note: mercury was often used to treat syphilis, hence the connection with the first clue