Natron, Ancient Egyptian Chemical Salt and Preservative

The Chemical Used by Ancient Egyptians to Preserve Their Mummies

Flamingoes at Lake Natron
Marc Veraart

Natron is a chemical salt (Na2CO3), which was used by the ancient Bronze Age societies in the eastern Mediterranean for a wide range of purposes, most importantly as an ingredient in making glass, and as a preservative used in making mummies. 

Natron can be created out of ash from plants that grow in salt marshes (called halophytic plants) or mined from natural deposits. The main source for Egyptian mummy-making was at Wadi Natrun, northwest of Cairo. Another important natural deposit used primarily for glass-making was at Chalastra, in the Macedonian region of Greece. 

800px-Mummy_Ahmose-Nefertari_Smith.JPG
Oh, mummy! Ahmose-Nefertari still looks good today. G. Elliot Smith (1871-1937)/Public Domain/Wikimedia Commons

Mummy Preservation

Beginning as long ago as 3500 BCE, the ancient Egyptians mummified their wealthy dead in various ways. During the New Kingdom (ca. 1550-1099 BCE), the process included the removal and preservation of internal organs. Certain organs such as the lungs and intestines were placed into decorated Canopic jars that symbolized protection by the Gods. The body was then preserved with natron while the heart was typically left untouched and inside of the body. The brain was often physically discarded. 

Natron's salt properties worked to preserve the mummy in three ways:

  • Dried the moisture in the flesh thereby inhibiting the growth of bacteria
  • Degreased the body fats by removing moisture-filled fat cells
  • Served as a microbial disinfectant.

Natron was stripped from the body's skin after 40 days and the cavities were filled with items such as linen, herbs, sand, and sawdust. The skin was coated with resin, then the body was wrapped in resin-coated linen bandages. This entire process took about two and a half months for those that could afford to embalm.

Earliest Use 

Natron is a salt, and salts and brines have been used in all cultures for a number of uses. Natron was used in Egyptian glass-making at least as long ago as the Badarian period of early 4th millennium BCE, and likely in mummy-making about the same time. By 1000 BCE, glass makers throughout the Mediterranean used natron as the flux elements. 

Knossos Palace on Crete was built with large blocks of gypsum, a mineral related to natron; the Romans used NaCl as money or "salarium," which is how English got the word "salary." The Greek writer Herodotus reported natron's use in mummy-making the 6th century BCE. 

Making or Mining Natron

Natron can be made by collecting plants from salt marshes, burning them until they are at the ash stage and then mixing it with soda lime. In addition, natron is found in natural deposits in Africa in places such as Lake Magadi, Kenya, and Lake Natron in Tanzania, and in Greece at Lake Pikrolimni. The mineral is typically found alongside gypsum and calcite, both also important to Mediterranean Bronze Age societies.

Natron Glass - Unguent Bottle - New Kingdom 18th or 19th Dynasty
Natron Glass - Unguent Bottle - New Kingdom 18th or 19th Dynasty. Claire H

Characteristics and Use

Natural natron varies in color with the deposit. It can be pure white, or darker grey or yellow. It has a soapy texture when mixed with water, and was used anciently as a soap and mouthwash, and as a disinfectant for cuts and other wounds. 

Natron was an important component for making ceramics, paints—it is an important element in the recipe for the paint known as Egyptian blue—glassmaking, and metals. Natron was also used to make faience, the high-tech substitute for precious gems in Egyptian society. 

Today, natron is not used as readily in modern-day society, having been replaced with commercial detergent items along with soda ash, which made up for its use as a soap, glass-maker and household items. Natron has decreased dramatically in use since its popularity in the 1800s.

Egyptian Etymology

The name natron comes from the term Nitron, which derives from Egypt as a synonym for sodium bicarbonate. Natron was from the 1680's French word which was derived directly from Arabic's natrun. The latter was from Greek's nitron. It is also known as the chemical sodium which is symbolized as Na.

Sources

Bertman, Stephen. The Genesis of Science: The Story of Greek Imagination. Amherst, New York: Prometheus Books, 2010. Print.

Dotsika, E., et al. "A Natron Source at Pikrolimni Lake in Greece? Geochemical Evidence." Journal of Geochemical Exploration 103.2-3 (2009): 133-43. Print.

Noble, Joseph Veach. "The Technique of Egyptian Faience." American Journal of Archaeology 73.4 (1969): 435–39. Print.

Tite, M.S., et al. "The Composition of the Soda-Rich and Mixed Alkali Plant Ashes Used in the Production of Glass." Journal of Archaeological Science 33 (2006): 1284-92. Print.