Autolysis is believed to start four minutes after death. It means self-digestion and comes from the Greek auto meaning ‘self’ and lysis meaning ‘split’ or ‘separation’. (That’s why ‘electrolysis’ in beauty clinics means ‘the separation of the hair from the body, using electricity’.) It’s self-digestion because the intrinsic enzymes we have in our cells, normally useful for breaking down unwanted molecules, are released after death. They roam unchecked in the body, like rioters aware of a sudden lack of a police presence, who can’t control the path of their own destruction once they’ve begun. One particularly self-destructive organ, the pancreas – responsible for producing the enzymes that help us digest food – simply digests itself. This is ‘abiotic’ decomposition (meaning ‘without life’ – a breakdown caused by chemical processes). It leads to an imbalance in the cells’ structures and an increase in fluids which can cause blisters full of red or brown fluid to bloom on the skin; their eventual bursting causes skin sloughage, or ‘skin-slip’, about a week or so after death. It’s this sloughage that enables us to remove the skin of the decomp’s hand, like a glove, and wear it over our own latex to fingerprint the dead, if necessary. It can make tattoos and bruising, which are naturally positioned in the deeper layers of the skin, much more visible – so we tend to use a damp sponge to wipe off this layer, which comes away like stocking fabric. The blisters, heavy with dark red fluid, burst at the slightest touch or movement of the body anyway, hence the need for the industrial-strength wrapping in the fridge before PM.
Bloat
The very descriptive ‘bloat’ stage of decay is characterised by a swelling of the body and colour changes, both caused by the actions of microbes. This is putrefaction. Where autolysis is abiotic, putrefaction is simply biotic, relying on the activity of microbes in the body: living helpers and not enzymes. These microbes are always present in humans during life but, due to the effects of autolysis and the subsequent breakdown of cells, they are able to invade the usually prohibited parts of the living host, and, to top it off, they are also suddenly awash with nutrient-rich fluids, so they basically go ‘on a bender’. The gastric population does include fungi but the majority is the ‘normal flora’ of the gut such as the genera Lactobacilli and Clostridia (one is the helpfully named Clostridium cadaveris so there’s no doubt as to when it’s this particular bacterium’s time to shine). We’re all far more aware of our friendly bacteria now thanks to Multibionta and Yakult adverts on TV, and it’s worth remembering that the more of this flora you have in your system, the quicker you’ll putrefy when the time comes. That’s one to remember when you are encouraged to take the Actimel challenge!
Although putrefaction occurs just after death, it takes a few days for the signs to become noticeable. The bacteria cause the colour fluctuations in the skin from green to purple to black because haemoglobin, which gives blood its red colour, is changed to sulphaemoglobin, a different substance containing infamously smelly sulphur. Because of their start position in the gut, the first obvious sign of decay is usually a greenish patch in the lower right of the abdomen (above the caecum) which eventually moves across the belly and over the rest of the body. This green patch is such an irrevocable indication of decomposition it’s one of the reasons those Dead Houses and Waiting Mortuaries were created in the 1800s. As Dr Maze pointed out in Quigley’s The Corpse: A History, ‘The only sure sign of death is putrefaction.’ As well as protecting the living from the dead, there was the added benefit of the dead not being buried until this was witnessed, thus ensuring they weren’t buried alive.
Soon, the effect of putrefaction can be very clearly seen across the shoulders and thighs as marbling, caused by the pigment from the colour-changing microbes taking the path of least resistance through the veins – at first, anyway. Eventually, the vessels also disintegrate and the bacteria roam even more freely. Gases build up in the tissues from the actions of all the bacteria, particularly Clostridium perfringens, which also causes the delightful-sounding ‘gas gangrene’ in the living. C. perfringens produces what mortuary-types call ‘tissue gas’; it’s this gas that makes a crackling or popping sound, called crepitation, when the cadaver is handled, as the flesh has become aerated just like a chocolate Aero (although much less palatable). The gas has very few places to go so it builds up in the cells. It sometimes escapes via the intestine as a post-mortem fart or through the mouth as a burp or groan (both indescribably smelly), but for the most part the collapse of the various natural exit tubes means the deceased begins to swell to an unnatural size. Without an escape route the tongue and eyes protrude, the genitals become engorged and the abdomen reaches what can only be described as ‘bovine’ proportions due to the increase in internal pressure.
I discovered the presence of this gas the hard way during my first ever decomp autopsy, when my boss, Andrew, watched me bend over the deceased, right over the top of the body, so I could see what I was doing. I took my PM40 and confidently made the incision as I normally would, yet when the blade breached the skin of the distended abdomen the green, taut flesh rippled and burst like a balloon from hell and I was rewarded with a face full of the most hideous gas I’d ever smelled in my entire life. I was wearing a face shield but it was no match for this eruption. To give you an idea of how it smelled, let’s first consider the names of these gases: putrescine and cadaverine, created when proteins break down. Then there’s hydrogen sulfide (rotten eggs) and methane (farts). There’s also a compound called Skatole which I think would be more honestly represented if it were pronounced ‘scat-hole’, since ‘skato’ and therefore ‘scat’ are derived from the Greek meaning dung. I turned to Andrew, eyes narrowed behind a visor splattered in yellow and green globules, with a look that said Why didn’t you warn me? To which he laughed and replied, ‘Well, you’ll never forget to stand back in future.’
Lesson well and truly learned, sir, and that’s the reason I’m now reluctant to remove my face visor, despite the discomfort …
Piercing the abdomen at post-mortem offers this putrid gas an escape route, but in the absence of that a body may well continue to swell, forcing fluids out through orifices, becoming larger and larger until it actually bursts – by now perhaps a fortnight or so after death. And, yes, it may seem unbelievable but we do still need to carry out a full autopsy: the organs all need to be removed and inspected, which is not easy when they have totally lost their structural integrity. They go from being fairly distinct shapes of a very soft consistency to literally becoming a pulp. At this point everything is a pulp: organs, fat, liquid oozing from blisters. I’d try to remove the organs and they’d just run through my fingers like molasses.
One of the most interesting aspects of this decomposition stage is how totally unrecognisable it makes the cadaver, obscuring the person’s real size, race, hair colour and facial features, sometimes even gender. In a small city like Liverpool, many deaths would be reported in the local newspaper as obituaries, with accompanying pictures of the deceased while they were alive. When working on a decomp case I’d build up a mental image of the patient only to find out later they looked nothing like I imagined, and it’s this that taught me early on that visible identification of a decomposed decedent by family or friend is frequently not reliable enough.
Active Decay
This is the period of greatest mass loss because excess fluid will have been purged and gases will have left the body by some means (perhaps a wet-behind-the-ears autopsy technician with a sadistic manager swallowed most of it, who knows?).
The mass of the cadaver also decreases, meaning much of the body’s flesh is consumed, because of the insatiable scavenging action of many creatures, among them my old friend, the maggot. As revolting as they may seem, flies and their larvae – maggots – are created perfectly for the job they need to do and many experts call them ‘the unseen undertakers of the world’. Those oviparous flies which lay their eggs on the dead, and which I referred to earlier as the sort you’d expect to find in the UK,
are mainly bluebottles from the Calliphora genus, which have a very reliable scavenging schedule. They lay eggs on orifices or wounds only, because the very young larvae need to eat decaying flesh but can’t break the skin to feed. These flies arrive on the scene within twenty-four hours – as though they have a flash-mob Facebook group and receive notifications – depositing eggs which then hatch the next day. Another type of fly has a slight advantage in that it’s viviparous and doesn’t lay eggs but tiny maggots, which can start consuming flesh immediately. These are descriptively named Sarcophagidae or ‘flesh flies’.*
Hundreds of these tiny larvae feed and feed, increasing in size through three different stages, or ‘instars’, at the rate of one every twenty-four hours. By the time they’ve reached their largest size, or third instar, they are a writhing mass of plump white ‘rice’. Their feeding frenzy produces so much energy it can warm the cadaver by up to 50ºC, and the maggots in the centre which overheat gradually migrate to the outside of the pulsing mass to cool down and allow others to access the middle in white rippling waves. They dive headfirst into their nutrient-rich banquet, so dedicated to feeding they’ve developed hooks on their heads to keep them attached to the slippery surface, moist from the enzymes they secrete to dissolve the flesh in order to slurp it. The two little dots at the other end, which look like they could be tiny black eyes, are actually spiracles, used to breathe out of their backsides. They are perfect little feeding machines which don’t need to stop and come up for air, which is why they can consume 60 per cent of a human body in one week. When they are finally sated, they slink away slowly for a lie-down, much like we do after a huge meal; but the difference is they pupate, as when caterpillars become chrysalises, whereas we just put the TV on and fall into a carb-coma.
When working on decomp cases those wriggling maggots ended up everywhere: in my hair, inside my steel-toed boots, caught in the folds of my clothes and, of course, in my bra. And I couldn’t simply brush them up and put them in a bin because they’d still pupate and the pupae are very resilient, like hard little nuts. There was only one way to deal with them: using the vacuum attachment of our head saw, I’d hoover them all up into a clean bag; then I’d put it on the PM room floor and jump up and down on it. It was very therapeutic, like pressing bubble wrap: I’d hear each one pop under my heavy boots until, a bit like popcorn in the microwave, the sound became less and less frequent so I knew I’d popped most of them. Then I’d throw the whole thing in an incineration bag with a tight cable tie and put it in the incinerator waste.
Maggot Girl turned on her own people.
Advanced Decay
This fourth stage of decay is loosely begun when the last of the satisfied maggots has rolled off the corpse and slithered off into a dark crevice to wait for its pupa to form. This can be up to fifty metres away, a huge distance for a creature which is only a centimetre long (that equates to a distance of about five kilometres for humans). During this phase the mass of the cadaver will have decreased considerably, which is why we are not knee deep in corpses; but the fluids created by the actions of autolysis and putrefaction will be evident in the surrounding floor, whether it’s wood, carpet or soil.
The maggot is now quite resilient, having somehow avoided ‘trial by hoover and boot’, encased in a hard material inside which it will remain for ten to twenty days – and let’s face it, after that ordeal it deserves a long rest. Any escapees will eventually emerge as cocky flies but without much time to show off: they’ll start buzzing around the PM room then hit the strategically placed ‘Insectocutors’ and die in tiny sparks of glory, making the blue light flash on and off as if it were at a disco.
Maggots’ association with the dead is well established but increasingly the general public has become aware of their use on the living. Maggot therapy is a form of treatment used for debriding necrotic tissue from wounds – basically removing dead tissue and leaving the healthy tissue alone. Even though the practice has been known of since antiquity it was more popular pre-antibiotics – around the 1930s – but has become so again since the medical world realised some microbes were becoming resistant to antibiotics, for example MRSA (Methicillin-resistant Staphylococcus aureus). On battlefields it was noticed that maggots would colonise the wounds of some soldiers and in those instances the injuries were less likely to be fatal; ostensibly, the maggots were eating away the infection and cleaning the wounds better than any other method known to physicians at the time, ensuring in the process that the wounded soldiers were spared from the blood poisoning which our anorexic dentist had succumbed to. Their use for this type of debridement is much lauded today and they are seen as beneficial, if a little gruesome.
But there is something maggots may be less well known for and that is the infestation of living creatures, including humans – a phenomenon known as myiasis. During our external examinations, as well as checking for bruises, tattoos and other artefacts both ante- and post-mortem, it’s imperative that we raise the deceased onto their side and inspect the back. Imagine forgetting to do this, puzzling over how on earth a person died, then flipping them over to discover a huge shotgun wound between the shoulder blades! The full examination, carried out in the same front-and-back sequence each time, ensures this doesn’t happen. What I was never prepared for were those unfortunate, neglected souls who had suffered from myiasis. It can occur in vulnerable humans who have been mistreated, for example children still in the same filthy nappy they’ve had on for weeks because of negligent parents, or old people left in one position to defecate on their bed and form bedsores, which subsequently become infected by their excrement, which is why it’s frequently found on the posterior surface. It’s an unnatural infestation, a consequence of man’s heinous inhumanity to man, and something which once seen can never be forgotten.
So I feel justified in my enthusiasm for the natural ecosystem of a decaying corpse and the creatures that contribute to a sacred cycle of life. To me it’s better than pondering those other actions which are most inhuman and unnatural.
Dry Remains
Finally, we come to a relatively more manageable stage of decomposition, which is classed as ‘dry remains’ because only bones, cartilage and toughened skin are left. This category can include the familiar sights of bog bodies in museums and Egyptian mummification. The Egyptians may have called it ‘embalming’ but unlike modern embalming it was really just a way to dry out and preserve the remains, with each step having a profound religious significance for them. During the process, most organs were removed from the body via an incision in the left side and placed into canopic jars. The flesh was washed with water from the Nile and covered in salt for forty days, and dehydrating materials such as linen and sawdust were used to give shape and mop up moisture. Specific oils were added to the proceedings for their meaning and their properties.* The exact process was never replicated until 2011 when Channel 4 made the documentary Mummifying Alan. In this programme, body donor Alan Billis had consented to be the recipient of this procedure after his death, and the team involved a forensic pathologist I’ve worked with closely many times, Professor Peter Vanezis.
But mummification can happen naturally in environments that are very warm and dry. I encountered several naturally mummified cases, frequently from homes which had the heating left on and no access for flies to the cadaver. In the past, one of the most common scenarios was the mummification of babies who, perhaps after being stillborn, were hidden inside the walls of houses by terrified young mothers. We have one such example in the collection at the Pathology Museum, and similar babies are sadly discovered in the fireplaces of old houses quite frequently. Mummification can also happen in cold, dry climates which is why we sometimes find bog bodies – deceased people who’ve been naturally preserved in peat bogs or similar – thousands of years later, preserved down to their eyelashes.
* * *
As a student of decomposition and decay I am familiar with all these stages, yet somewhere a decision seems to have bee
n made about which of these states are suitable for general viewing. When you think about it, the last stage – dry remains – is a much more common sight than bloat or advanced decay. We may see dry remains in museums, on TV documentaries and even in newspaper articles about the latest archaeological find, but we never see maggot-infested corpses strewn around with the same abandon. In fact, the only time this happens is during horror movies, when they are used as a device to scare the bejesus out of us in one way or another. But why is one stage more acceptable for general consumption than the other? Is it because, as Christine Quigley says, ‘the skeleton denuded of its facial features has less impact than the preserved head of a mummy, which in turn has less impact than the face of an intact corpse’?
The images of the decomposing deceased, whether via museums or media, are one-dimensional without the accompanying smells, most of which I described above. When discussing the cloying scent of decay the jury is out as to whether it really does cling to your hair and clothes as is so often mentioned in crime books and on TV. I was told by one pathologist that it’s not the case. In fact, the delicate odour molecules simply cling to the hairs and folds inside your nasal passages making it seem as though you’re smelling it on you all day, but it’s from the inside, not the outside.
Perhaps that is true, but often as an APT, once I’d done autopsies and even showered and changed my scrubs, I’d head home in my own clothes and still get a pretty wide berth on the bus.
Five
Penetration: ‘Rose Cottage’
The Chick and the Dead Page 9