used
by plasterers. We know it to be dense for Pliny writes that it was
adulterated with boiled and compressed Cimolia earth. In De Ortu et Causis Subterraneorum I have explained how it was formed since shells are found in it.6
It is not sea foam for the salt would render it useless to plasterers.
It is an earth formed from an unctuous rock such as limestone that has
been altered. One can see this type of earth at Alfeld, Saxony, where
it is sometimes found containing shells. This earth also occurs in
Cyrenaica, Egypt, and on the island of Crete. Since it has never been
used in medicine nothing is known regarding its taste for a painter
does not use taste in classifying earths.
Lemnia earth takes its name from the island of Lemnos.7 There it is collected into mounds and burnt near a town named for Hephaestus.8 This earth has many names, "Red Lemnia Earth" on account of its color, Lemnium sigillum or stamped Lemnia earth, sigillum caprae since
it is sometimes stamped with the sign of Diana, a she-goat, in the same
way as it is stamped today with Turkish letters. It is a red, unctuous,
soft, dense, astringent earth which is sold in the markets today. Galen
describes it as unctuous and when writing about lotions says that "a
priest dries the unctuous mud until it has the consistency of wax." We
know it is dense for Galen writes that it is the same weight as Samian aster. Dios-corides
also describes it as being dense. Galen writes that it is slightly
astringent and is red in color but differs from the red Samian earth in
that it does not soil the hands. There are three varieties. One is
sacred, according to Galen, and is not handled by anyone except the
priests; another is the red earth used by artisans; the third is a
fuller's earth. Since Lemnium sigillum is unctuous it is slightly glutinous and gummy; being dense it is heavy; being soft and dry it crushes easily as does Samian aster. Drunk with water and vinegar it stops bleeding and mixed with the juice of the plantain9 it cures colic. It has greater medicinal potency than Samian aster and for that reason when placed on an inflamed skin, especially a tender skin, it is irritating.
Eretria earth, according to Pliny, takes its name from the city where it is found, Eretria,10 on the island of Euboea. This city is near Chalcis, the
•
Book III, page 41, line 21. "A pure or simple earth is formed along
channels in the following manner. Rain, which the outer portion of the
earth absorbs, first permeates and passes through the earth itself and
is mixed with it. Then it is collected from all sides into veins and
stringers. There sometimes this water, sometimes water of another
origin tears away the earths from them. Much is worn away if the veins
and stringers are in earth, little if in rock. But it does wear away
even the rocks themselves, more by continual movement, especially the
softer ones. Members of the latter genus are calcareous from which are
produced chalks, clays, marls, Paretonium, and other unctuous earths,
or arenaceous from which are produced barren earths."
7 This earth is also known as Lemnian bole, asphragide, etc.
8 The God of fire and metal working.
9 A common weed of the genus Plantago.
10 Modern Aletria.