Term of the ancient Greek literature (in ancient Greek: lemnia ge) referring to a kind of red argillaceous soil with healing properties, which was extracted exclusively in Limnos. According to Theophrastos (4th century BC), Pliny (1st century AD), Galen (2nd-3rd century AD) and other Greek and Latin writers, Terra Lemnia was a medication suitable for the cure of many illnesses, but mainly of lumps, bleeding, inflammations, as well as dog and reptile bites.
The extraction site of Terra Lemnia is identified as the location presently known as Agiochoma, approximately 1 km southwest of the Pournias bay. In ancient times, the area was under the supervision of Hephaistia, the most important city of the island, on the bay's eastern exit. Agiochoma is located at the foot of Mosychlos (presently known as "Despotis"), the mountain where, according to Greek mythology, Hephaistos fell after he was banished from Mount Olympos. The mythological correlations coupled with the volcanic rock characterizing the area constributed in the bestowal to Terra Lemnia of miraculous qualities. Moreover, according to Limnian Philostratos (3rd century AD), it even helped cure the mythical hero Philoctetes. The extraction of terra was conducted under the supervision of the local clergy that sealed the soil, which was put up in a set, in order for its transportation to be controlled and its authenticity to be certified. For that reason, the sealed healing tablets were also known as "Lemnia Sphragis" or "Terra Sigillata".
After a long period during which the practice of extraction and transportation of Terra Lemnia had declined, the healing preparation stirred the general interest following 1479, when Limnos came under Ottoman rule. At that time the ancient extraction ceremony was revived, taking place on the 6th of August (during the Christian feast of the Transfiguration of the Saviour), in the presence of local authorities, both Greek and Ottoman. According to detailed descriptions of western European travellers, like Pierre Belon (1546), André Thévet (1549) and others that followed, terra was always collected with great care and was sealed according to the ancient model, although at that stage they used the Ottoman inscription tin-i mahtum ("sealed clay"). The use and distribution of the healing substance remained the exclusive privilege of the Ottoman ruling class and of the sultan himself. During the Ottoman Period, Terra Lemnia was considered a medication suitable for the cure of the typhoid fever and the plague. The prescription of Greek pharmacologist Dioskorides (1st century AD), according to which Terra Lemnia was an effective antidote for lethal poisons, inspired the use of the precious soil for the construction of clay vessels, which were believed to protect their owner from drinking suspicious liquids.
It was the first standard drug in the history of medicine.
Analyses of both past and nowadays reveal that the Lemnia land consists mainly of silica and alumina clay. It also contains a high percentage of iron oxides (4-6%) that gives the characteristic color-brown. The shade is called "moderate reddish brown" and is appointed as No. 43 of color atlas of the world called Terra Lemnia.