Selection of a conservation process for Lindow Man

Abstract

The normal processes of decomposition start soon after death and, under normal circumstances, it may be only a matter of days before a human body loses recognisable form. However, in a few instances human bodies have retained a recognisable appearance for hundreds, or even thousands, of years by preservation due to natural circumstances. Rapid desiccation produced by burial in dry sand produces preservation by reducing the water content of the body below a point where microorganisms will thrive. Alternatively, the presence of large quantities of salts, e.g. the use of natron by the ancient Egyptians, can produce preservation (1). Extreme cold can halt the deterioration of animal flesh is well known from our domestic freezers, but as soon as temperatures return to normal, biodeterioration sets in. However, natural freeze-drying can occur to bodies in cold regions when water vapour from ice in bodies is removed by sublimation into cold air currents resulting in preservation by desiccation. The majority of examples of body preservation in northern Europe occur due to accidental or intentional burial in peat bogs. Skin and hair are often preserved but internal organs less frequently. There are over 120 recorded sites where human remains have been discovered in bogs in Great Britain and Ireland (1). The conditions are often quoted to be anaerobic, acidic and wet, and until recently these conditions were considered to be those necessary for the preservation of skin. However, Painter (2) suggests that bodies are preserved in sphagnum peat bogs because they are tanned by spagnan, a pectin-like polysaccharide from the cell walls of sphagnum mosses. Additionally, sphagnan aids preservation by reacting with the digestive enzymes secreted by putrefactive bacteria and immobilising them on the surface of the peat.