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Archaeological medicinal earths as antibacterial agents: the case of the Basel Lemnian sphragides.

Photos-Jones, E.; Edwards, C.; Häner, F.; Lawton, L.; Keane, C.; Leanord, A.; Perdikatsis, V.


E. Photos-Jones

F. Häner

C. Keane

A. Leanord

V. Perdikatsis


This paper presents the scientific investigation of three Lemnian sphragides (terra sigillata), a famed medicinal clay (earth) of antiquity, dated to the 16th-17th century, and presently in the collection of the Museum for the History of Pharmacy of the University of Basel. The three specimens are examined here against the backdrop of samples of sedimentary clays from the purported locality of its extraction, at Kotsinas, NE Lemnos, Greece. The study demonstrates, for the first time, that the three Lemnian sphragides displayed antibacterial properties against gram positive pathogens (staphelococcus aureus); the modern clays displayed none. Subsequent analysis with DPLC-MS of one of the three sphragides and one sample of clay revealed the presence of organic constituents in the sphragis which were absent from a sample of the modern clay. A fungal secondary metabolite is proposed here as the molecule responsible but other factors may have a role to play. The ongoing investigation for the bioactivity od some medicinal clays might aid in the re-evaluation of Belon's statement included at the start of this paper, namely, that the Lemnian Earth worked only because people in the past wished it to work.


PHOTOS-JONES, E., EDWARDS, C., HANER, F., LAWTON, L., KEAN, C., LEANORD, A. and PERDIKATSIS, V. 2017. Archaeological medicinal earths as antibacterial agents: the case of the Basel Lemnian sphragides. Geological society: special publications. Geology and medicine: historical connections [online], 452, pages 141-153. Available from:

Journal Article Type Article
Acceptance Date Feb 2, 2017
Online Publication Date Feb 2, 2017
Publication Date Jul 31, 2017
Deposit Date Mar 2, 2017
Publicly Available Date Feb 3, 2018
Journal Geology and medicine: historical connections
Print ISSN 0305-8719
Electronic ISSN 2041-4927
Publisher Geological Society
Peer Reviewed Peer Reviewed
Volume 452
Pages 141-153
Keywords Lemnian sphragides; Medicinal clays; Geoarchaeology; Antibacterials
Public URL


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