At the May meeting of the Essex Egyptology Group Robert Loynes talked to us about his work on Ancient Egyptian mummies. He's a retired orthopaedic surgeon who has subsequently achieved a PhD in Egyptology (from Manchester) using modern medical technology to investigate ancient mummies.
Loynes began by telling us about what is known about Ancient Egyptian mummification techniques. Despite the Egyptians love of writing things down the contemporary sources actually don't tell us anything - what we know is pieced together from later writings and examination of the actual mummies. The first mention of mummification techniques comes from Herodotus around 450 BCE, and it is next discussed by Diodorus Siculus in the 1st Century BCE.
The Egyptians believed that for eternal life one needed the following: one's whole body, one's name, one's Ka and one's Ba. But the reality is that bodies decay and fall apart, so some sort of preservation is necessary followed by rituals that return it to life. In prehistoric times bodies were buried in pits in the sand, and the contact with the dry sand accidentally mummified them. But as society got more sophisticated then higher statues individuals got more elaborate burials in tombs - which isolated them from the sand, and prevented natural mummification. As Loynes pointed out, the layout of tombs with an offering chapel in relatively close proximity to the burial chamber would leave people in no doubt as to what was going on down there! And so they developed a process to artificially dry out & preserve the body.
To make a mummy the Egyptian way the first thing that needs to be done is to remove the soft & squishy bits that wouldn't dry easily - the organs from the torso and the brain. In actual fact the brain would've been fine if it was left in the body, but the Egyptians didn't know this so as it looked squishy they took it out. The rest of the internal organs were preserved in canopic jars and buried with the mummy. Next the body was cleansed with perfumed water & oils, before being dried in natron. Natron is a sort of naturally occurring salt with other sodium compounds as well as NaCl. The embalmers packed it inside the body as well as covering the body with natron. This increased the contact between body & salt thus drying it quicker, and also filled up the space left behind when the organs were removed. Drying the body took 30-40 days, and then almost as long was spent bandaging it and performing rituals. During the bandaging process amulets were placed in the wrappings to protect & aid the deceased in the afterlife. The rituals included the Opening of the Mouth ceremony which reactivated all the senses of the deceased. After this the mummy was covered in resins for protection - the Egyptians believed this worked via magic, but we now know that the resins they used have antibacterial properties.
Loynes next gave us a history of medical imaging in the context of what can be used to see inside mummies. The development of modern techniques has been very helpful for people working on mummies (whether Egyptian or not), as it means you don't have to destroy the subject (by unwrapping it and/or dissecting it) to find out what's inside. X-rays were discovered in 1895 and as we all know they shine through the soft tissue & reveal the solid bits (bones etc) on the inside. Modern X-ray images are much more detailed than the first images, but they still have the problem that you see all the internal structures on top of each other with no indication of relative depths in the body. The CAT scan process was invented in 1975, and it solves this problem. CAT scans use multiple X-ray images from different angles around the specimen, and these images are then merged on a computer to generate an image of a virtual slice through the specimen. The machine then moves along and captures data for another slice, and so on. Then the software stitches together all these slices into a 3-dimensional model of the whole thing. As computers have got faster, and the software has got more sophisticated, the virtual slices have got much thinner and so show much more detail in the final model. Modern software lets you manipulate the model, so now you can dissect a mummy in a non-destructive way.
Having introduced the subject to us Loynes moved on to telling us about things he has seen when examining CAT scans of Egyptian mummies. One thing he has investigated is the routes the embalmers used to remove the brain - it's not always removed the same way. Some mummies show evidence that the thin bit of bone at the top of the nose (the nose septum) has been broken and the brain extracted this way - this matches what Herodotus wrote. Another potential route is for the brain to come out via the base of the skull, to do this the neck must be disturbed which shows up clearly in the CAT scans. Some mummies, however, show evidence of neither of these routes - their nasal septum is intact, and the neck is undisturbed. In these cases Loynes has looked for other possible routes: sometimes in children the embalmers have taken the brain out through the base of the skull which is much thinner than in adults. Other mummies show signs that the brain was removed via the eyes.
The eyes themselves are treated differently in different time periods. Before Dynasty 22 half or more of mummies have nothing done to the eyes. After Dynasty 22 the mummies eyes are generally packed to mimic the shape of living eyes (dessicated eyes are too flat), and between Dynasty 22 & 28 eyes plates are also used which provide the right visual appearance.
After a break for tea & cake Loynes returned to the evidence he's seen in mummies of how they were mummified - now moving from the head to the torso. Herodotus described two routes to the removal of the internal organs - via an incision on the left flank or via the perineum. Loynes has seen evidence of both of these on CAT scans of mummies, and showed us examples. It's also clear that the Ancient Egyptians tended to repack the body cavity after removal of the organs. This is something that might be done for two different classes of reason: practical or ritual. Loynes has surveyed the types & quantities of materials used to see if there's evidence supporting either conclusion but the answer is not clear cut & obvious. On the one hand the materials used are cheap, which suggests that the packing filled a practical purpose. But on the other hand frequently only small quantities were used, certainly not enough to fill the cavity, which suggests that it served a ritual purpose.
CAT scans also let you see what's been added to a mummy while it was being prepared. The most well known of these types of objects are amulets, and Loynes showed us examples of these. Other things are more unusual - in one mummy Loynes discovered there was an ibis inside the wrappings as well as a person! He speculated that this might indicate the person was involved in the worship of Thoth or was a scribe. There are also sometimes more practical (as opposed to ritual) objects - for instance he has seen mummies that have been strengthened (or put back together) with planks and rods, some inside the body, some outside the body.
Loynes also talked a bit about the signs of disease, injury & causes of death that you can detect using CAT scans of mummies. There's actually not much evidence of disease, as the soft tissues of the body are either removed or dessicated during the mummification process - so you really only see evidence of things that affect the bones. One Roman period mummy that he's looked at appears to've been beaten to death. The body is that of an old man, and he's suffered several fractures in the face, the skull, the arms, the spine & the pelvis. Loynes also showed an example of one of the soft tissues diseases that he did detect - gall stones show up clearly on the scan. That mummy also had a spinal fracture and heel fractures which are consistent with landing from a great height on the feet.
Another thing that Loynes has investigated is how the mummies he's examined shed light on the development of mummification techniques from the 18th Dynasty onwards. The first example he showed us was of the mummy of Nebri "Head of Stables" - a title that makes him one of the high elite, as horses were new to Egyptian culture in the New Kingdom. Nebri lived during Tutmosis III's reign, and all that remains of him is his head and his four canopic jars all of which are now in the Turin Egyptian Museum. The CAT scan of his head that Loynes examined was also used to produce a virtual skull that was then used to create a facial reconstruction of Nebri. In terms of technique his mummification was very sophisticated, but there wasn't much of the brain removed. Packing (including the eyes) was a key feature.
The Third Intermediate Period (22nd to 25th Dynasty) example that Loynes showed us had more packing of the mummy and the body cavity was completely filled. The brain removal was also done in a subtly different way - the hole through the nasal septum was at a different angle (less vertical than in the 18th Dynasty). In the Ptolemaic period the hole in the nasal septum to remove the brain is once again at a more vertical angle. In the example he showed us there was resin inside the body cavity, and it had visibly soaked into the spine. The internal organs had been removed via the perineal route, and the higher organs (lungs, heart) were still present in the body.
The Roman period mummies that he's examined have something strange happening with the ribs - it's impossible to dislocate one's ribs in life, but that's what has happened in these mummies. He's looked at the wrapping styles of around 30 Roman era mummies, and one distinctive group is the "red shroud mummies". The red colour comes from red lead, from Spain. This group includes the older man who was beaten to death that he showed us earlier in the talk, and the man who had an ibis bird inside his mummy.
One trend is that from the Old Kingdom period to the Roman period there is less & less emphasis on the tomb. And so by the Roman era the mummification techniques have become more about the final external appearance of the body. I think this correlates with something Manon Y. Schutz said last month (my write up is here) when she talked about a 2nd Century CE coffin bed which appeared to function symbolically as a temple within the tomb (rather than the tomb itself playing that sort of role).
Loynes has examined 90 mummies so far, and is hoping to look at lots more so that he can draw more robust conclusions. Even tho 90 seems a reasonable sample size once they've been separated by time period, geographic location or other factors each group ends up quite small which makes teasing out what is a unique feature of a particular mummy or what is a common feature of the group more difficult.
During the questions at the end someone asked about the hearts of the mummies he's examined. For theological/ritual purposes the heart is supposed to be replaced in the body so that the weighing of the heart can take place in the afterlife. But Loynes says that in practice the heart is normally no longer there, and replaced with a heart scarab.
In the questions he also showed us one of the other ways modern technology can be used to investigate mummies. He had a 3D printed model of an incision plate from the inside of a mummy which had been made using the data from a CAT scan, which I think is a really cool way that modern technology is letting us "unwrap" mummies without destroying them.