Mercury amalgam mirror

Recently I accepted an 18th century Venetian mirror for treatment
and I find that I have now become very interested in the subject of
mercury amalgam. I realized that the mirror was deteriorated when I
accepted the piece but at the time my plan was to clean the colored
glass decorations, repairing those that were broken and leave the
mirror pieces alone except for a light surface cleaning in situ.

Today, as I removed one of the colored glass pieces to wash it, I
noticed tiny balls of free mercury laying on the surface of the
adjacent mirror. I collected them into a sample jar and together
they make up a ball the size of the top of a glass headed straight
pin.  As I examined the mirror frame more closely, I found what
amounts to an equal amount of mercury in various nail holes in the
wood where I had removed other pieces of the decorative glass. I
have only removed approximately 1/4 of the decorative glass pieces
so I have no idea how much more I am likely to find, however, some
of these holes were as much as 4" from any of the mirror pieces.

I now have a number of questions.  First, how dangerous is this
amount of mercury to me and potentially to my client, especially if
the client has young children?  I presume that it will not be
possible for me to remove all of the free mercury from the mirror. I
have ordered a mercury spill kit from Lab Safety Supply which
appears to have a metal based powder that amalgamates the free
mercury. It has also been suggested to me that I sprinkle elemental
sulphur on the mercury to convert the metallic mercury into mercuric
sulfide. What else should I be doing? Has anyone else had this
problem and if so, how have you handled it?

A previous post to the OSG-List suggested using Hxtal to
consolidate the backing.  Has anyone tried this and if so, did it
work? Does it bind the mercury? The mirrors are not plain flat
panes. Each of the pieces I'm dealing with has a design  in it.

What alternatives can I suggest to my client? Can the mirrors be
resilvered safely?  Ethically, should they be? Is safety a bigger
consideration than originality?

I would really appreciate information and suggestions from those of
you who have had experience with this problem.

Linda Strauss

                                  ***
                  Conservation DistList Instance 11:18
                  Distributed: Friday, August 22, 1997
                       Message Id: cdl-11-18-009
                                  ***