What Is So Special About Mercury?

Mercury is a metal.  But what makes it special is that it is liquid at normal temperatures, but it is not wet!  It is impossibel to pick up mercury, or sweep it up without it breaking into globules.  It is for this reason that mercury is sometimes referred to as quicksilver.
Mercury is poisonous if inhaled, if it gets into the bloodstream or is absorbed through the skin (mercury poisoning).  However, if mercury is eaten, it is unlikely to have any ill effects, because the gut does not absorb it, so it would simply pass through the bowels.
If heated mercury becomes a very toxic vapour, so for this reason if some is spilt on the ground, it should never be vacuumed up.
The main domestic uses for mercury are within thermometer and barometers.  However, with digital technology advancing, the use of mercury within these is declining and it may soon become obselete.