...The plaques was then warmed to evaporate the mercury. So where
did the mercury go?
It is evaporated. Upon hitting cooler air, it most likely
precipitates again, I’d guess as very finely divided particles, that
then settle out. If you heat the mercury mixed metal in a closed
container and feed the fumes to a condenser, you can condense it back
out and reclaim it. In medieval times, if they did this, it was
probably not real efficient. So a fair amount of the mercury fume can
be presumed to have ended up in the workmens lungs. Where it most
certainly is toxic.
And isn't a silver filing in one's tooth done in the same
Not quite. The mercury filling is never heated, What you end up
with is a silver amalgam, which for all intents and purposes, can be
thought of as an alloy of silver and mercury, with the main difference
being that it does not have the regular ordered crystaline structure
of an ordinary alloy that’s been melted and allowed to solidify.
Everyone worries about whether silver in fillings is toxic, but so
far, all research has suggested that the mercury in that amalgam form
seems stable and is not causing toxicity problems. Still, many
prudent dentists and patients are not taking chances with silver
filling anymore, just in case.
Is metallic mercury in vapour form as toxic as ionic mercury or
Toxic, yes. But nowhere NEAR as toxic as some of the other forms,
such as methyl mercury as you mention. Thats the compount that a few
years ago, made the news when on brief, minor exposure to a lab tech’s
hand, covered with a latex glove, still absorbed enough through the
glove (which turns out to enhance absorbtion) and skin, from just that
one drip, to kill the poor lady. Took many months, but still killed
her. A HIGHLY potent neurotoxin, as I recall. Metallic mercury, if I
recall right, tends to accumulate in fat deposits, where it’s not
eliminated. It too causes neurotoxic effects, but so far as I know,
it takes a lot more of it, and more time.