Sorry about the confusion, but time's not on my side.

Many years ago when I first started working for the US NPS, I read a volume,
probably aimed at folk art collectors about the early problems of production
and the results then unexpected. The term in the book was about the origin of
"mad as a hatter" which resulted from the treatment of hats with chemicals.
The author related another practice that resulted in poisoning in a few cases
leading to an early appreciation of the danger of mercury fumes and vapors
(which badly affected many natives in the Americas as it was used to amalgam
gold then burnt off, a Spanish mining technique still used today if my
"historical geology" memory serves me). The particular object he referred to
was a glass sphere, mirrored on the outside, from mercury, or maybe mercury
and tin as shown in Diederot for plate mirrors, which were hung near the
chimney and held salt, the purpose to keep the salt dry and "witches away."
The author related that the practice had been in use until about the end of
W.W.II in Western England, that is Great Britain. For the life of me, I can't
remember the title of the book but I seem to think it was about Pennsylvanian
Arts and Crafts. My memory doesn't recall a picture of these so I can't
relate if they looked like Japanese glass fishing floats or a hanging
planter. I imagine one, on a large cooking hearth, might want the salt that
close by, or if salting fish, a warm fire to dry by.

The author's point was definitely in the production and not in the use, the
worker not the consumer in the formula.

George J. Myers, Jr.