The introduction of a new sixteenth-century drug: terra Silesiaca.

THE discovery of a new drug, terra Silesiaca, in the sixteenth century and the publicity and experimentation that were a part of marketing it provide an interesting insight into the medical practice and the pharmaceutical trade of that period. Various earths had long been used in medicine as alexipharmics, astringents, and absorbents. In the first century AD, Dioscorides and Pliny the Elder described the medicinal virtues of the valuable earths obtained from Lemnos, Eretria, Samos, Selinous, Chios, Cimolus, and Melos. 1,2 The reputation of certain medicinal earths was further established in the second century by the Greek physician, Galen. In the ninth book of his De simplicium medicamentorum temperamentis ac facultatibus, he wrote of these earths, commenting especially on that found on the island of Lemnos. From personal observations, he gave details of the collecting of this red earth and its manufacture into small sealed or stamped troches. The seal, an image of Diana, authenticated its purity and source. The Lemnian terra sigillata was good for healing ulcers, for diarrhoea, for the bites of snakes, mad dogs, and other animals, for provoking vomiting, and for the plague.3 Medieval Moslem and European physicians continued to recognize the uses of medicinal earths. Avicenna (d. 1037) wrote of the earths of Lemnos, Samos, and Cimolus, among others, and in the same century, Serapion the Younger included terra sigillata in his work on simples.4 The Moslem pharmacologist Ibn al-Baitar (d. 1248) cited authorities on a number of earths including that of Lemnos.5 In the West, Matthaeus Silvaticus (d. c. 1342) listed lutum samium and terra sigillata in his comprehensive catalogue of drugs.6 Late in the fifteenth century, the famous Gart der Gesundheit dwelt at some length on terra sigillata as did the Latin Hortus sanitatis.7 Although the famous Lemnian sealed earth remained the most popular earth in