Silver tarnish

Dominique Cocuzza <domi [at] squidco__com> writes

>My institution, New York Historical Society, is planning a new
>visible storage facility.  The collection includes 3,000 silver
>hollowware objects, nearly all of which will be on view.  As these
>objects are not lacquered and will be stored on birch veneer
>(medite) plywood, I would like to know other institutions'
>experiences in preventing tarnish.  How do I calculate the rate of
>filtered air exchange?

Instead of filtering the air we would recommend the use of Miracle
Sac. This is a solid granule adsorbent formulated specially to
remove from the air hydrogen sulfide, carbonyl sulfide, and
mercaptans which cause tarnishing. The adsorbent can remove these
contaminants down to below ppb (parts per billion) from closed
display cases, storage and transit cases with the result that once
polished the article will remain in pristine condition provided the
Miracle Sac is in place.

The granules have been used in museums British Museum,
London--Woolfson Gallery, Ashmolean Museum, Oxford, Staaliche Museen
Zu Berlin, Germany, Museum of Fine Arts, Boston, USA in the loose
form. By packing them in an unobtrusive sachet they can be dispersed
around the display cases.

Miracle Sac is available in porous sachets which are benign both in
the unused and spent form.  The spent material is non-hazardous and
can be disposed of in domestic refuse.  The anticipated lifetime per
sachet depends on the volume and degree of atmospheric pollutants
present.  It is recommended one sachet be used for approximately six
months/cubic ft.  The adsorbent chemically bonds the impurities into
its structure to form a new compound.

Further details regarding Miracle Sac can be obtained from

    Icel Developments Ltd.
    15 Fairview Way
    Edgware
    Middlesex HA8 8JE
    44-181-958 7452
    Fax: 44-181-954 2667
    iceldevp [at] btinternet__com

Dr. Colin L. Leci
Technical Director
Icel Developments Ltd.

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                  Conservation DistList Instance 12:61
                Distributed: Wednesday, January 27, 1999
                       Message Id: cdl-12-61-008
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