Preservation of the Tollund Man
To preserve means to prevent (organic bodies) from decaying and many items from prehistoric times are so fragile that they have to be preserved before you can touch them.
When the Tollundmanden was discovered in 1950, the Danish scientists had never before been faced with the task of preserving a bog body. In the 19th Century German scientists had made an attempt. They had attempted to preserve it by smoking it the same way as you smoke meat because they knew that smoke prevents organic things from decomposing. The result was successful but the smoking also caused the bog body to dry out and shrink.
All living organisms are made of cells. In order to preserve a bog body the scientists had to find some kind of substance to replace the bog water which was currently filling out the hollow spaces in the cells. If the bog water drained without being replaced by something else, the same thing would happen as what happens to flowers if you take them out of a vase and let them dry out - they lose their colour and shrink.
The two museum conservators who did the excavation of the Tollund Man at the National Museum of Denmark, were also the ones who were going to try to attempt to preserve his head. They wanted to try to replace the bog water in the cells with wax. But since they knew that the melted wax wasn't going to mix with bog water, they had to take a detour: first they put the head in alcohol which replaced the bog water, then they put it in toluol, which is a liquid of dissolution, and finally they replaced the toluol with liquid paraffin.
Now the cells contained liquid which could be mixed with wax. They chose bees' wax which melts and is of low viscosity at 83 degrees celcius and at the same time is non-perishable. This is illustrated by the fact that archaelogists have discovered a candle made of bees' wax from the viking age which had been preserved for more than 1,000 years in the ground.
Thus, the melted bees' wax insinuated itself in to the cells and replaced the paraffin. After six months of preservation the scientists were able to remove the Tollund Man's head from the container just before Christmas of 1951. It was cooled off and the wax left on the outside of the skin was washed off. It was clear that the attempt had been successful in preserving the head perfectly: all the features of the face had been preserved whereas the head in general had shrunk approximately 12%.
Unfortunately the body was not preserved but dried out, leaving hardly more than the bones. However, it does mean that the unpreserved bones and soft parts will give the scientists the opportunity to make new examinations of the Tollund Man in the future .
Later on Silkeborg Museum decided to recreate the body, so it now appears as it did when it was first discovered.