ATM Mercury: from the liquid mirror thread

[astillma@nit.AirTouch.COM (Anthony Stillman)]

Ah Mercury, liquid silver.  Mercury is bad stuff, not as a metal, but as a
vapor and a salt.  Luckely, Mercury has a fairly low vapor pressure, which
in addition to being part of the reason it was used in diffusion pumps (
high mocular weight and a low boiling point being the others) it means 
that there is very little Mercury vapor above a open pool at room temperature.
  Warning, this does not mean there is none, only that the average 8 year old
playing with the contents of a broken thermometor is not going to go mad.

As a vapor, mercury is taken in through the lungs, where thankfully it mostly
remains a metal.  Some is converted into salts and a few other componds
which go to work on the central nervous system.  This can lead to tremmors,
ticks, loss of muscle control, weakness, headaches, insanity, skin
discoloration, leagions, unexplained sores that wouldn't heal, death,...
Touching mercury is equaly bad as the oils on our skin convert the metal to
a salt which is then absorbed through the skin which leads to ...

Oddly, injecting mercury into muscle isn't that bad.  There it remains a metal
and is fairly safe.

I almost lost a friend to mercury poising.  He inhaled little more than a
one drop of vaporized mercury.  With out porper care he would be dead now.

Another friend inadvertently injected him self in the leg with about a cc
of mercury.  He was given a choice.  The doctors (ones who actually had
some experience with this) said it wouldn't matter if it was left in and
taking it out would damage his leg and possible make it worse.  He had it
removed.

The treatment for mercury poisoning hasn't changed much from the days of
the mad hatters (mercury was used in the felting process hence people who
made felt hats would be exposed to mercury and eventually go mad.)  Mostly,
it involves sweating, though there are a couple of chemicals which will
help keep mercury a metal in the body.

Bottom line if you can avoid mercury, do.  Of course it is a very useful
substance, and with proper precautions can be handled safely.

When working with mercury:
     Always wear gloves
     Always wear a mask designed to stop mercury
     Keep a certified mercury containment and clean up kit on hand
     Design your work area so that if a container fails there is a
       back up containment system
     Always work in a well vanilated area, a hood is better still.
     Be serious

One other item

1 troy ounce        = 31.103 grams
1 avoirdupois ounce = 28.350 grams

Anthony