James Waldby on Thu, 5 Mar 2020 07:54:24 -0000
(UTC) typed in rec.crafts.metalworking the following:

Same here ... however, copy/paste into Google Translate gives ok
results: "5. Maintenance \ Because of the unhindered air access,
the mercury level in the lower vessel oxidizes over time. If the
oxidation has progressed so far that the tip of the scale can no
longer be reliably adjusted to the lower mercury level, the
mercury in the vessel should be removed from the barometer and
cleaned. \ CAUTION! \ The mercury may only be cleaned by
qualified specialist personnel."

A couple of other places talk about sending it in for repair; eg
at the end of section 3, "If it is not possible to remove any air
bubbles that are in front of the air trap or if air has entered
the vacuum chamber, the device must be sent in for repair."

Interestingly, the last paragraph about mercury barometers in
https://en.wikipedia.org/wiki/Barometer#Mercury_barometers
says, "On June 5, 2007, a European Union directive was enacted
to restrict the sale of mercury, thus effectively ending the
production of new mercury barometers in Europe."

Aha! Bwahahahaha.

This is the metal working group, yes?

So of course, check out Cinnabar.

All you have to do is crush the ore and roast it.

"The process of extraction of the mercury is relatively simple. An
oxygen furnace can be used to heat up the ore cinnabar and condenses
the fumes of mercury released from the process."

Better than buying the stuff in a store, and "you made it
yourself!"
--
pyotr filipivich
"With Age comes Wisdom. Although far too often, Age travels alone."