Risks Associated with the use of Mercury
Mercury is a poison hazard and thus contact has to be avoided. In the "old days" where Mercury manometers were used extensively special "mercury bays" were utilised to mitigate the hazard. Contact with Mercury can cause brain damage. I suppose you have heard the term "As mad as a hatter", well this was the result of the hatters utilising mercury to put the sheen on top hats. Mind you I have experienced a few mad Instrument Technicians who worked in the Mercury Bays as well!