[MUSIC] So what do we do if the body that we found has been there for several days, and it's already cooled down to ambient temperature, and the Livor Mortis and the Rigor Mortis have both passed? Well, probably what we would have to do at this stage is to look at the state of putrefaction of the body, and once again, this needs an experienced person to make a judgment and give his opinion. So what is putrefaction and how does it happen? Well, when you're dead, of course, you're dead, but all the microorganisms that live inside you, they're not dead, and they keep on going and they will start to eat you. Essentially they will take your tissues and they will break them down chemically and use them as nutrition. But as a by-product, they will produce all sorts of chemicals, including gases and volatile chemicals, and it's these chemicals produced by putrefaction that give an abandoned dead body its particular smell. And if you've ever walked past a ditch where there's a dead dog, you know what I mean. So, an experienced examiner can look at the body and make a judgment. Of course, he does have to take into effect all sorts of environmental factors, particularly temperature. If it's a very hot place, rather than a very cold place, then of course, there's going to be a big difference in the rates. You also get effects due to drug use, because if someone has been a heavy drug user, the presence of all those drugs in their body can affect the rate of which the microorganisms do their stuff. And again, this relies on experience. So, one of the problems is there's not many hard scientific studies on the rate of decomposition of human bodies. So, some studies are ongoing. One of them is, as you see, at the University of Tennessee, Knoxville, where they have a so-called "Body Farm", which is an area of open ground which they fenced off, and they will place donated bodies in particular situations - clothed or unclothed, partially buried, etc. - and then they can scientifically observe the process of putrefaction, and maybe this will make estimates more scientifically reliable. Well, during putrefaction, this is roughly what happens. After a few days, the body will start to discolour and also it will start to swell. The reason for the swelling is the gases produced by the putrefaction process are inflating the body slowly, like a balloon. As the days go past, the staining spreads and the veins of the body start to become discoloured as the materials in your blood decompose. Further days pass, the abdomen swells even more as more gas is developed by the putrefaction process. The skin starts to blister, and eventually the abdomen will become very tight and swollen because of all the gas inside. The tissues also break down, so the tissues lose their structural integrity, and they start to soften. And that means that the organs and cavities inside the body, which have been filled with these putrefaction gases, then burst, a little bit like balloons. In addition, the fingernails will no longer be attached to the fingers and they will fall off. So in a typical case, maybe in four weeks, the soft tissues will be starting to liquefy, and one of the consequences of this is that the face is no longer recognizable. So if the body is found at this stage, somebody just looking at it can't tell who it is, and it will have to be identified by other means. So, a body exposed to the elements will ultimately turn into a skeleton. How long this takes is very dependent on environmental factors, so some people in some places might say it takes several years. Here in hot, tropical Singapore, it can take as little as two weeks for that to occur. Now, not all bodies putrefy. If the environmental conditions are right, particularly if the conditions are extremely dry, then the body will become mummified and the tissues will actually be preserved. So mummification does happen by accident because the body happens to be in those circumstances. But of course, the most famous kinds of mummification is where it has been done deliberately. So these four gentlemen in the slide here were all mummified. There's Pharaoh Ramses the Second of Egypt. This is Lenin, the founder of Communist Russia, who was mummified and preserved by having a secret chemical injected into him after his death, and his body is still there in Moscow. If the Russians did it, then of course the Chinese did it. So there's Chairman Mao. And the last of these four gentlemen actually specifically wished to be mummified, and he said so. And he is Jeremy Bentham, the English philosopher who was also the founder of University College London, and if you go to University College London, you can go and see him there, he's still there. [BLANK-AUDIO]
