Preserved through time

Stone, metal and pottery are almost indestructible, and are often found at ancient sites. But organic materials such as wood and clothing are subject to biological decay- a process which requires oxygen, moisture, and warmth. If one of these three conditions is removed, the material has a chance of survival.

In exceptional circumstances, Organic remains have been preserved by chemicals. In the salt mines of early Celtic Europe, leather rucksacks and clothing used by miners survived intact- the salt drew any moisture out of the objects. Tannic acid, which occurs naturally in plants help to preserve human bodies in environments such as bogs. It destroys bone but preserves the soft tissues by pushing water out of the skin and cementing its protein fibers together. The ancient Egyptians mummified bodies using Natron, a dehydrating mineral gathered from the beds and shores of lakes.

Pockets of oxygen free soil combined with chemicals were responsible for the survival of a series of wooden writing tablets bearing letter to roman soldiers serving on Hadrian’s Wall; these included one – perhaps from an anxious mother- about a parcel of warm underwear she had sent.

Rivers and lakes inhibit the decay of organic materials because the lack oxygen- which is vital to the micro organisms that cause decay. Europeans of the Iron Age and later regarded watery places as scared and left offerings in them or metal work and even wooden boats. Many European lakes contain the remains of wooden villages once built on their margins. Submerged costal settlements and shipwrecks are damaged by ocean movements and the micro organisms and corrosive salts in sea water, but once settled in silt, the chances of survival are high. The oldest surviving wreck is a Canaanite ship sunk at Kas, off Anatolia, in about 1350BC.