Natural Science in Archaeology

10.7 Other Geologic Raw Materials 243
Mercury was distilled off as a final step. This process is mentioned in Pliny (N.H.
33, 32.99–100) and was a common practice in the Middle Ages (Singer et al. I
1954). Mercury was found in silver and lead mines and was used in the process of
gilding copper and gold leaf. Mercury was also used in ancient pharmacopea. The
physician Paracelsus (1493–1541) noted that syphilis could be treated successfully
by ingestion of mercury compounds.
The discovery that liquid mercury metal was used in ancient Mayan ceremonies
at Lamanai, Belize, led to a study of possible sources. Other Mayan sites
had also produced evidence of the use of mercury (Pendergast 1982). There are
a number of cinnabar (HgS) deposits in Mexico and a few of native mercury.
Pendergast discussed the geography of the deposits and the likelihood that use of
mercury by the Maya reflected a painstaking process that spanned a long period
of time. Haury (1976) suggests that the Hohokam peoples of Arizona, USA,
used cinnabar as a body paint, securing the material from deposits in southwest
Arizona.
10.7.5 Saltpeter, Niter
Niter (KNO 3 ) or potassium nitrate, often called saltpeter, occurs as an efflorescence
in caverns and on soils in arid regions. Extensive deposits are found in many of the
world’s arid regions including parts of Spain, Italy, Iran, India, Russia, Egypt, and
the Arabian Peninsula. The name “niter” might derive from the ancient Egyptian
city of Nitria which is located near niter deposits. In ancient times, niter also was
extracted from the ashes of vegetable matter.
Although referred to in the Bible, biblical “niter” is actually natron, an entirely
different substance (Wright and Chadbourne 1970). Classical and early translations
frequently use the word niter for natron, which was used in glass making and mummification.
For example, Tacitus discusses the use of niter in making glass by fusing
niter with sand from Palestine and Syria, but this substance is not identified with
potassium nitrate. After they had traveled in Egypt (ca. 1550), Peter Ballon and
Prosper Alpinus introduced the word “niter” into Europe in order to distinguish
soda and potash (natron) from saltpeter (niter). The word “natron” was introduced
into mineralogy by Linnaeus in 1736 and applied to soda only (Singer et al. II
1954). Lucas (1989) notes that no evidence can be found that niter was either known
or used in ancient Egypt.
Niter is an important element in the manufacture of explosives. The Chinese
were the first to recognize and purify potassium nitrate, from which they
developed gunpowder. The earliest record of its use as an explosive is found in
a formula for the use of sulfur, saltpeter, charcoal, and pitch with other vegetable
ingredients as recorded in the Wu Ching Tsung Yao, written in 1044 CE
(Singer et al. II 1954). At present, the way in which the method of making gunpowder
passed from China to Europe is unknown. However, it is possible that
Arab travelers and merchants were the first to identify gunpowder in their travels