CHAP. 33. (13.)—POMPHOLYX.
The substances called pompholyx [Note] and spodos [Note] are also
found in the furnaces of copper-smelting works; the difference
between them being, that pompholyx is disengaged by washing,
while spodos is not washed. Some persons have called the
part which is white and very light "pompholyx," and say that
it is the ashes of copper and cadmia; whereas spodos is darker
and heavier, being a substance scraped from the walls of the
furnace, mixed with extinguished sparks from the metal, and
sometimes with the residue of coals. When vinegar is combined
with it, pompholyx emits a coppery smell, and if it is touched
with the tongue, the taste is most abominable. It is useful as
an ingredient in ophthalmic preparations for all diseases of the
eyes, as also for all the purposes for which spodos is used;
this last only differing from it in its action being less powerful.
It is also used for plasters, when required to be gently
cooling and desiccative. For all these purposes it is more
efficacious when it has been moistened with wine
