Conserving Egyptian Collections, day 2

Posted on September 5, 2014 by mollygleeson

Update – this post contains outdated language. We no longer use the term “mummy” and instead use “mummified human individuals” to refer to Ancient Egyptian people whose bodies were preserved for the afterlife. To read more about this decision, follow this link.

Day 2 of Understanding Egyptian Collections at the Ashmolean featured 11 speakers (including myself), and the papers covered a wide range of topics.

The front entrance of the Ashmolean Museum

I didn’t take any photos during the talks, so I have less visual content to share for this post. For ease of sharing the information about the presentations, I’m going to list the talks here, with speakers names, titles, and brief remarks (all of the talks over the 2 days deserve way more attention than I give them here and in my previous post – hopefully a publication will result – see more about this below). Several of the talks had co-authors, but I’m only listing the co-authors names if they were present at the meeting.

“Evolving Attitudes: past and present treatment of Egyptian Collections of the Oriental Institute.” Alison Whyte, Associate Conservator, Oriental Institute. Alison shared many old archival photos which have helped conservators understand old restorations, and make decisions about how to revisit the conservation of objects that have been in their collection for a long time. Alison also shared the project of the guest curator Rozenn Bailleul-LeSuer of the special exhibit “Between Heaven and Earth – Birds in Ancient Egypt“. Rozenn’s work included CT-scanning and making a 3D print of an eagle mummy, and 3D replicas of its skeletal remains. She brought a 3D print of the eagle mummy to show us, but unfortunately it got lost on her way to the conference along with the rest of her luggage! Let’s hope that it eventually turns up.

“Mummy case saved by LEGO: a collaborative approach to conservation of an Ancient Egyptian cartonnage.” Sophie Rowe, Conservator, and Julie Dawson, Senior Assistant Keeper, Conservation, Fitzwillliam Museum, University of Cambridge. I was familiar with this project due to the fact that it was prominently featured in the news last year. This project was a collaboration between conservators and engineering student David Knowles, who designed a structure to support a cartonnage coffin upside-down during treatment, and devised a plan to use LEGO structures to provide long-term support for the coffin from the interior. To the right is an image of the LEGO structure (it looks a little different from the LEGOs we’re all familiar with).

“The importance of technical analysis and research for the conservation and display of archaeological garments.” Anne Kwaspen, Conservator of the Archaeological Textile Collection, Katoen Natie. I had never heard of Katoen Natie before – it is a company based in Antwerp that has invested in collecting art, through a program called HeadquARTers. They have a collection of archaeological textiles from the art market and private collectors. Anne discussed the study and conservation of their Egyptian wool and linen tunics, and their approach to display.

“Problems and possibilities for the Petrie Museum’s pottery display.” Susanna Pancaldo, Senior Conservator, UCL Museums and Collections. Susanna spoke about recent upgrades to the pottery room at the Petrie Museum. Their pottery room has approximately 3400 objects on display in 36 cases, and was suffering from issues with light, extremes in relative humidity and temperature, lack of mounts and damaging mounts, lack of space, and outdated/minimal labels. In 2014 they received funding to make improvements, including new lighting, new interpretive information, the addition of an introductory showcase showing Petrie’s sequence dating technique, and to carry out conservation surveys and treatments, among other things.

“Innovations for the display of Dynastic textiles using existing designs at the Metropolitan Museum of Art.” Emilia Cortes, Conservator, Metropolitan Museum of Art. Emilia’s presentation focused on the remounting of Egyptian textiles on exhibit to allow for easier access. She showed how she was able to modify existing mounts for elaborate, intricate objects, including this incredible floral collar from Tutankhamun’s embalming cache. Her retrofits included the innovative use of food-grade silicone for preventing movement of objects on exhibit.

“King Menkaure in Motion: the metamorphosis of a Monolithic royal sculpture from the Old Kingdom.” Susanne Gansicke, Conservator, Museum of Fine Arts, Boston. Susanne described the monumental task of moving their King Menkaure statue from one gallery to another within the Museum of Fine Arts. With 2 years lead time, they were able to do gamma radiography of the sculpture in the gallery to help prepare and make decisions about the move, which involved setting the statue on a lifting frame, with 12 wheels attached, and then moving it with the assistance of 2 lifts. It was a very thoughtful project and an impressive feat!

“On not exhibiting a corpse: the Mummy Chamber, Brooklyn Museum.” Lisa Bruno, Head Objects Conservator, Brooklyn Museum of Art. In preparation for the museum’s new “Mummy Chamber“, conservators at the Brooklyn Museum worked on 2 unwrapped mummies, Pa-seba-khai-en-ipet and an anonymous man. The anonymous man, who was methodically unwrapped in the late 1950s, with the procedures documented in the book Wrapped for Eternity, was rewrapped in the conservation lab for display. The decision was made not to display the remains of Pa-seba-khai-en-ipet due to his poor condition, and ultimately, because displaying his remains would mean displaying a corpse, not a mummy.

“Reflecting on Egyptian Pigments: the use of Fibre Optic Reflectance Spectroscopy (FORS) for pigment analysis at the Fitzwilliam Museum.” Jennifer Marchant, Antiquities Conservator, and Abigail Granville, Pigment Analyst, Fitzwilliam Museum, University of Cambridge. Jennifer and Abigail discussed their use of FORS to analyze pigments using a FieldSpec 4 spectroradiometer, which measures in the UV/visible/near IR range. They are building their own reference library, and finding that it is useful as an initial non-invasive examination method, and may be used in the examination of varnishes and binding media as well.

“A case for keeping: the life and afterlife of ritual metal statuary in Ancient Egypt.” Deborah Schorsch, Sherman Fairchild Center for Objects Conservation, Metropolitan Museum of Art. Deborah spoke about examples of Egyptian metal statues in collections around the world that show evidence of reworking for various reasons, often for the purpose of the object serving a new ritual function, or removing details in order to retire objects. One example she spoke about at length was the copper and gold Hierakonpolis falcon in the Egyptian Museum in Cairo. This statue had 4 different phases, with new material being added in each phase of its life.

“Bringing it all together In the Artifact Lab: Conservation, research, display, interpretation.” (Me! I spoke about working on Egyptian material and mummies in a public space, and some of the unique interactions and investigations that we have carried out as a result of the working environment.)

“Ancient Worlds: Open data, mobile web, haptics, digital touch.” Stephen Devine, Digital Communications Officer, and Sam Sportun, Collection Care Manager/Senior Conservator, Manchester Museum. Stephen and Sam introduced us all to Haptic technology and how it is being used at the Manchester Museum to allow visitors to “handle” artifacts. They also spoke at length about the importance of mobile technology and the development of an app to allow visitors to explore and provide feedback about their Ancient Worlds exhibit.

Ashmolean Head of Conservation Mark Norman gave the closing remarks, and expressed their interest in producing a publication from the conference. All of the talks were also filmed, and the conference organizers are planning on making the talks available via iTunesU.

I also should mention that there were several posters at the conference, which were presented on a monitor as a slideshow, and the poster presenters were given ipads to share their “posters” during the breaks. I’m sorry to say that I didn’t have a chance to see several of the posters, so I’m hoping this content will be made available in the future as well!

It was a short, but very worthwhile trip to Oxford. I hope to have the opportunity to return soon.

Christ Church buildings as seen from Tom Quad

Peptide Mass Fingerprinting (PMF)

Posted on May 9, 2014 by mollygleeson

Motivated to learn more about the fur and animal hair found in our Predynastic mummy bundle, I popped up to Boston yesterday for a workshop entitled “Identifying collagen-based materials in cultural objects using peptide mass fingerprinting“.

The workshop was organized by a group at Harvard, including the Peabody Museum of Archaeology and Ethnology in collaboration with the Straus Center for Conservation at the Harvard Art Museums and the Harvard FAS Division of Science. The team received NCPTT funding for a project to develop a new application of an analytical technique called peptide mass fingerprinting (PMF).

PMF uses mass spectrometry to analyze very tiny samples of proteinaceous objects and identify the mammalian source to the species level. It actually can be used to analyze materials made of collagen and keratin, but the group at Harvard is focusing on collagen-based materials. The procedure essentially breaks up the protein into smaller peptides, and the mass of the peptides is measured using a mass spectrometer such as a MALDI-TOF. The peptide masses are compared to known reference samples, which allow for identification. This type of analysis falls under the category of proteomics, or the large-scale study of proteins, and it is sometimes referred to by this name as well.

The Harvard project is focused on applying this technique to objects made of gut, skin, sinew, and membrane from Alaska, the Northwest Coast, Northern California, and the High Plains. Another goal of the project is to bring this type of analysis, which typically takes place in large industrial or academic labs, to museum labs. You can learn more about the project on their blog.

The workshop included 3 presentations by the project’s primary analytical investigator/scientist Dr. Dan Kirby, project research associate Madeline Corona, and Kress fellow Ellen Promise. Between the 3 of them, they covered how PMF works, what it can tell you, and how it is applied to cultural artifacts, using a project on Alaskan kayaks as a case study.

After Q&A led by Peabody Museum conservator T. Rose Holdcraft, we were led on a tour of the Peabody conservation lab, where we were able to feast our eyes on some of the impressive Native Alaskan objects that they are investigating as part of the project.

A view of the Peabody Museum conservation lab, with several Native Alaskan skin and gut objects on view

A view of the Peabody Museum conservation lab, with several Native Alaskan objects on view

We also toured the impressive Mass Spectrometry and Proteomics Resource Lab, where we had a chance to see the Bruker MALDI TOF/TOF instrument and a demonstration of how samples are prepped for analysis.

The Bruker MALDI-TOF/TOF instrument and Madeline Corona demonstrating sample prep

The sample prep area showing the equipment used, including the MALDI plate (lower right)

Here at Penn, we are excited by this technique – not only for the minute sample size required (the samples used are just barely detectable to the naked eye) but also for its accessibility. We have a lot of animal-based materials in our collection and we are hoping to pursue using PMF to analyze these materials. Actually, we are already working to see if its possible to use this technique to identify the sources of the fur and basketry hair fibers from our Predynastic mummy, thanks to help from Smithsonian MCI fellow Caroline Solazzo, whose work focuses on keratin-based materials. PMF supposedly works on all types of samples, including those that are very old and/or are in poor condition, so we thought we’d put this to the test by starting with samples from our oldest Egyptian mummy (he’s well over 6000 years old). We will let you know how it seems to work.

A side note – a quick trip to Boston wouldn’t be complete without a stop at the Museum of Fine Arts. I spent most of my time there ogling the Ancient Egypt exhibits, admiring the massive, yet delicately decorated and inscribed coffin boards of Djehutynakht’s outer coffin (same time period and style as Ahanakht’s coffin)

The interior of the lid of Governor Djehutynakht’s outer coffin (left) and detail of the false door (right)

and many of the other treasures of this collection, such as this bead net dress made of faience and gold from the 4th Dynasty.

Detail of a 4th Dynasty beadnet dress (ca. 2551-2528 BCE)

Breathtaking, really. I also found this shabti in a miniature coffin very charming.

Shabti of Queen Neferu with miniature coffin, from Deir el-Bahri, tomb of Queen Neferu, 11th Dynasty (ca. 2061-2010 BCE)

And while the MFA does not have conservators working in a gallery, as we are doing here at Penn, they do have some great “behind the scenes” galleries, one with interactives that engage visitors to think about conservation ethics and decision making. One of my favorites was an example using Maya Cylinder vases, examining condition issues and treatment decisions.

Some screen shots of the Maya vase example in the MFA's "behind the scenes" gallery

Some screen shots of the Maya vase example in one of the MFA’s “behind the scenes” galleries

All in all, a great trip. We’ll keep you updated on the whole peptide mass fingerprinting technique and how we might be able to use this for our collection.

Looking inside our falcon mummy

Posted on November 21, 2013 by mollygleeson

Last Friday, 7 of us from our conservation department took a group of objects from the museum to the GE Inspection Technologies Customer Solutions Center in Lewistown, PA for x-radiography and CT scanning.

Our group gathered around the CT scanner, being operated by Becky Rudolph, GE’s North American Radiography Sales Manager for Academia

Now, wait just a second, you might be thinking. Doesn’t Penn have its own x-ray and CT scanning equipment? Why did we have to take these objects all the way to Lewistown for this work? Good questions, and we have a good answer. We just received word that in early 2014, construction will begin on our new conservation labs, which will include a digital x-ray suite. We plan to purchase the x-ray unit from GE, so a visit to their facilities was a chance for us to demo the equipment using some of our own artifacts!

The object I was most eager to image was our falcon mummy. X-ray and CT (computed tomography) scanning technology allow us to “virtually unwrap” this mummy, helping us understand how it was made and what is inside (and as visitors to the lab have heard me say, we can’t assume that there are any falcon remains inside-we can only hope!).

The falcon mummy laying on its storage support on the x-ray plate (within a lead-lined room)

The falcon mummy lying on its storage support on the x-ray plate (within a lead-lined room)

The quickest way to get a peek inside the falcon mummy’s wrappings is by taking an x-ray image. Digital x-ray technology is amazing – with a push of a button, 135 kV (kilovolts, measurement of the voltage), 2.0 mA (millamperes, measurement of the current) and 4 seconds later, we saw this:

Hooray! In this first attempt, we could already see that there are bird remains inside. The bright white material concentrated in the center of the mummy wrappings is the skeletal remains. In radiographic images, materials that are denser appear white because they do not allow x-rays to pass through. Materials that are less dense (such as the textile wrappings surrounding the bird bones) appear darker, because the x-rays are penetrating and passing through these materials. We can see in the image above that there are no skeletal remains in the “head” and the “feet” of the falcon mummy – these areas appear to have been sculpted with fabric. The slightly brighter white area near the feet just reflects an overlap of textile in that area.

While we were excited by this image, it immediately prompted more questions. We can see bird bones, but where is the skull? How much of the bird body is present? Are there any clues as to how the body was prepared for mummification? To answer these questions, we turned to the CT scanner.

CT scanning uses x-rays to produce cross-sectional images of an object, which can then be combined to produce three-dimensional views. CT provides a much more detailed look inside objects, and better distinction between different materials.

The CT unit at GE does not look like a medical CT scanner that many people may be familiar with. To scan the falcon, we had to stand the mummy upright in its box, which we then secured to the rotating stage inside the CT chamber with masking tape.

Right: Lynn Grant and I taped the falcon mummy in his box to the stage inside the CT chamber. Left: another view of the falcon mummy's box secured inside the CT chamber.

Left: Lynn Grant and I taped the falcon mummy in its box to the stage inside the CT chamber Right: another view of the falcon mummy’s box secured inside the CT chamber

The CT scanning took a bit longer than 4 seconds, but again, produced much more detailed images. Here is what one of the cross-sections looks like:

In this image, the bones are visible as the most radio-opaque materials (so they are bright white). We were also excited to see the feathers, clearly visible as little circles reflecting the cross-section of the feather shafts, which are hollow. The various layers of linen wrapping are also very clear – clear enough to count! But other details are not so immediately clear to us, including the presence of the skull, and exactly how the remains were prepared.

Here is a screen shot from the program we are using to view the CT images, showing 3 different cross-sections, and a basic 3D rendering of a section of the falcon mummy. In this 3D rendering, we can clearly see the falcon’s talons, circled in red!

We will need to spend time with the images, and consult other specialists, to better understand what the CT scans have revealed.

UCLA/Getty graduate intern Alexis North and I puzzle over the CT images of the falcon mummy

We will follow up later with more images and interpretations of the falcon mummy CT scans, plus more about the other objects we were able to examine.

A special thank you to Becky Rudolph and Hank Rowe at GE for spending the day with us, and for their expertise!

X-ray excursion

Posted on November 14, 2013 by mollygleeson

If you stopped by the Artifact Lab this week, you might have noticed that our falcon mummy is no longer on display, and this sign in its place:

As indicated on the sign, the falcon has been removed for x-radiography. This mummy has never been x-rayed before, and we’re interested in using this imaging technology to learn how it was made and if there are any falcon remains inside!

Along with the falcon, we’re also going to be x-raying/CT-scanning our (possibly headless) cat mummy, the wooden statue heads, and several other pieces.

We do not have the ability to x-ray and CT-scan objects here in the museum, so we will be taking these selected pieces for a little trip tomorrow. In preparation for their travels, they are securely packed, and ready for this exciting excursion!

The falcon mummy is secured inside its storage support and packed into a larger box for travel.

We will update the blog with our findings soon after we return.

The 2013 Mummy Congress in Rio de Janeiro

Posted on August 21, 2013 by mollygleeson

Today we are featuring another guest-blogger: our pre-program conservation intern Melissa Miller. Melissa just returned from a pretty special mummy-related trip – read on to hear more about it!

From August 6-9^th, I had the opportunity to travel to Rio de Janeiro, Brazil and attend the World Congress on Mummy Studies.

This biannual conference brings together experts from all over the world to discuss recent and ongoing mummy research projects.

Mummy studies draw in a surprising variety of disciplines. There were experts in physical and cultural anthropology, conservation, paleopathology, paleoparasitology, dentistry, medicine, radiology and more. I listened to presentations on ancient DNA techniques, publishing e-books, parasites in coprolites, archaeological excavations in the Valley of the Kings, genetic analysis of the Iceman, and the list could go on. For 4 days I received a crash course on numerous mummy research projects from all over the world that have been going on for the last 15 years. Thankfully the Congress was videotaped and I will be able to revisit some talks or view some that I was unable to attend due to conflicts with other presentations.

While there, I was also able to present a poster on my ongoing research into the history and development of autopsied mummies, and the preservation of generated materials. For me this was perhaps the most valuable part of my experience at the Mummy Congress. Simply meeting all of these incredible and passionate people and listening to their advice, hearing their encouragement and seeing their willingness to help me continue my research was invaluable. Some have also granted me permission to interview them!

Looking towards the future, I plan to continue my research throughout the academic year and develop my senior thesis. Perhaps by the time the 9^th World Congress rolls around I will be able to present my finished project! Lastly, I would like to say that I am very grateful to all those at the University of Delaware and University of Pennsylvania Museum of Archaeology and Anthropology who made it possible for me to attend the Mummy Congress, and to all those at the Mummy Congress who offered their great advice and support.

Field trip!

Posted on August 3, 2013 by mollygleeson

Sometimes getting started on a conservation treatment requires getting out of the lab for a bit, so this week, my colleague Julie Lawson and I took a field trip down to Baltimore to visit the Johns Hopkins Archaeological Museum and chat mummy treatments with their Curator/Conservator, Sanchita Balachandran. Sanchita and I connected at the American Institute for Conservation (AIC) annual meeting back in June – I had read about a treatment that she carried out on a human mummy at the museum, and when we realized that we both had animal mummies in our labs as well, we decided we’d get together for a brainstorming session to discuss treatment approaches, materials, and storage options for these fragile objects.

Julie Lawson admires artifacts in one of the cases in the Johns Hopkins Archaeological Museum

The Johns Hopkins Archaeological Museum is nestled in the center of the Johns Hopkins Homewood Campus in Baltimore, in a beautifully-renovated building, surrounded by classrooms and light-filled student study spaces. The museum was established in 1882 and since its founding, has been dedicated to inspiring and teaching students at the university.

One of the main features of the museum is the display of archaeological objects from ancient Greece, Rome, Egypt, the Near East, and the ancient Americas, displayed in glass case walls, allowing students, faculty, and visitors to view these pieces and peer into the museum itself.

The museum also displays pieces on loan, including an ancient Egyptian mummy from Goucher College.

This was the mummy that I had read about and was curious to learn more about from Sanchita. The Goucher mummy is an adult female mummy from the Ptolemaic Period (305-30 BCE), and I knew some details of the treatment from Sanchita’s article in the Journal of the American Institute for Conservation (JAIC), but this was a great opportunity for me to see this mummy up-close and to ask Sanchita more about how she approached this treatment and the specific materials and techniques she used. Since we are in the middle of working on the treatment of our mummy PUM I here in the Artifact Lab, this conversation was very timely.

Detail of the Stabiltex encapsulating the feet of the Goucher mummy

The Goucher mummy has a fascinating history that I won’t get into here, but you can learn more about her in the “Object Stories” section of the museum’s website by following this link. One of the things I was curious to discuss more with Sanchita was her use of Stabiltex, a sheer polyester fabric, to protect fragile areas of the mummy’s wrappings, and the design and construction of the support the mummy is currently resting on in the exhibit. As I said, we’re working on encapsulating PUM I’s outer linen wrappings in a similar way, but using a different type of sheer netting fabric. After discussing techniques with Sanchita and seeing how successful her treatment of the Goucher mummy was, I returned to the Artifact Lab feeling good about our approach to PUM I’s treatment!

Sanchita also pulled out several animal mummies that she is currently working on, including these cuties:

Cat (above) and dog (below) mummies

We discussed the challenges of dealing with such fragile linen wrappings and our experiences with and use of different adhesives, as well as techniques for encapsulating fragile areas. Sanchita also showed us their handling and storage mounts, which go a long way in protecting these artifacts.

Sanchita lifts an ibis mummy from its storage box using a handling tray

After discussing mummies at length, Sanchita took us back into their storage area, where we had the opportunity to see additional Egyptian artifacts, including several painted wood artifacts with a variety of condition problems. As readers to this blog may know, we have our own fair share of challenging painted wooden artifacts, including Tawahibre’s coffin, so I was eager to see how Sanchita was approaching the treatment of these pieces as well.

Sanchita and Julie in storage

All in all, it was a fun and productive day! These types of professional exchanges are incredibly valuable, and I’m not only inspired to tackle some treatments and try new things back in the lab, but to make more time in the future to visit other colleagues and collections. A huge thanks to Sanchita for hosting us and for sharing so much about her work at Johns Hopkins.

Conservators-in-training

Posted on July 23, 2013 by mollygleeson

….

For over 10 years, our museum has organized an “Anthropologists in the Making” Summer Camp, and today we hosted 66 of these summer campers in the Artifact Lab for an afternoon of conservation training.

This year the camp is being held over 8 weeks, with different themes each week, including Can you Dig it?, all about archaeology, and Visions and Dreams, which explores the significance of dreams and the roles of shamans and mystics (this one is coming up in August).

The camp theme this week is Mummies Unwrapped so of course we had to give the campers a taste zxxcconservation, in addition to what they are learning about mummies and ancient Egypt.

We organized 3 different activities for the 7-13 year olds (they were split into 2 groups according to age) to test their hand and observation skills. All 3 activities were created to mimic some of the work that we’ve been doing in the Artifact Lab, including:

– an excavation station, which challenged the campers to pick out the remains of a beaded shroud from a bin of debris (similar to recovering PUM I’s beads)

– a cleaning station, where campers tried different cleaning tests to remove dirt from a painted ceramic tile (like the cleaning that we’ve been doing on our painted coffin of Tawahibre)

– a materials ID station, where the campers had the opportunity to examine “mystery” materials under magnification and then had to identify what they were looking at (an example of one of the material ID challenges we’ve encountered in the lab can be found here)

A camper compares reference materials to the magnified image of the “mystery” material on the monitor

For each activity, we had the kids fill out worksheets to record their observations, to give them a sense of the documentation involved in our work. Before moving on to the next station, each camper needed to get their supervising conservator to sign off on their worksheet. On their way out the door, all campers received certificates declaring them “Junior Conservators for-the-day”.

We had lots of fun, not only preparing for the camp

Arts and crafts day in the Artifact Lab (left) and the painted tiles before “dirtying” them for the campers (right)

but also working with the kids at each of the stations. We were impressed with their observations and how quickly they picked up on each activity (rolling swabs can be hard at first!). Special thanks to our Education Department and to all of the summer campers for increasing our department more than tenfold for the afternoon!

Investigation of a mummy bead “coating”

Posted on July 3, 2013 by mollygleeson

While we continue to work on the conservation of PUM I‘s remains, we also have been taking this opportunity to carry out some analysis on the residues and substances preserved on his wrappings and on the beads that once made up his beaded burial shroud.

Since the last time we wrote about these beads, we have recovered even more in the conservation process; we now have a total of 35 beads – all either tubular or circular in shape. As we wrote about in a previous post, all of the beads are covered with concretions, mostly a brown, waxy material. Here is an image of one of the beads before cleaning, and after partial exploratory cleaning, revealing the beautiful blue color of the bead:

A tubular bead before (left) and after (right) exploratory cleaning to remove the residue on the surface ( 10X magnification)

This material does not appear to be dirt or accumulated debris from the mummy. But, it can be removed rather easily from the beads, especially with the help of some mineral spirits, which suggested to me that it is some sort of wax.

Based on this information, I was suspecting that either this material was related to a substance applied to the beads to help the beaded shroud stay in place at the time of burial (but we have yet to locating any research supporting this theory – it was more common to sew or tie these beaded shrouds in place) or that it is related to a substance applied to the shroud at the time of discovery, to assist with the removal of the shroud.

In conservation, when it comes to investigating unknown, likely organic substances, there are several analytical techniques that can be helpful. One of these techniques is Fourier-transform infrared (FTIR) spectroscopy. FTIR works by exposing a sample to infrared radiation, which causes the sample to selectively absorb radiation, depending on the molecules present. The individual peaks in the resulting absorption spectrum can be analyzed or the spectrum can be compared to reference spectra to help characterize or identify a material.

We provided a small sample of our “bead coating” to Gretchen Hall, a consulting scholar in the Biomolecular Archaeology lab here at the museum. She ran the sample for us and provided the resulting spectrum and interpretation. Here is the spectrum produced by our sample:

This spectrum shows that the sample is mostly organic as evidenced by the dominant peaks in the 2900 cm-1 region which are characteristic of C-H bond stretches. In addition, there were many peaks in the “fingerprint” 1800-1000 cm-1 region where various organic molecules absorb. The absorption around 1730 cm-1 (due to C-O double bond stretches) suggests organic acids are present, possibly from resins or beeswax. Both of these families of compounds would also have bands around 1470 (a O-H bending absorption) which are seen in our sample. Importantly, the sample also shows a strong band around 720-730 cm-1 (due to the C-H in long hydrocarbon chains) which is only present in beeswax.

For comparison, here is our bead coating sample spectrum displayed just below the spectrum for a standard beeswax:

Based on this analysis, our “bead coating” sample likely contains some beeswax, which is consistent with our observations of the solubility and consistency of the material as well. It is known that beeswax was used in ancient Egypt – as an adhesive, a sealant, a binding medium, and in the mummification process. Bees were considered by the Egyptians to be precious insects with magical and economic prestige, and these values would have extended to their wax (Ikram and Dodson 1998).

For a more definite identification of our sample, the next step would be to analyze the material using gas chromatography–mass spectrometry (GC-MS).

Special thanks to the Biomolecular Archaeology Lab and Dr. Gretchen Hall for running this sample and providing the analysis.

New objects in the Artifact Lab

Posted on June 18, 2013 by mollygleeson

Starting today, there are new artifacts on view in the exhibit space here in the Artifact Lab. Those of you who have been keeping up with this blog will recognize these pieces, including:

Our falcon mummy:

and Nefrina’s cartonnage funerary mask:

All of these artifacts are displayed with labels explaining their conservation “story”.

In addition, we have a binder available in the exhibit space that includes the conservation treatment reports and images for each of these artifacts. These reports contain detailed descriptions of the materials and the condition of these artifacts, and of the techniques and materials used to conserve them.

Of course, we also have information about these pieces here on our blog, and later this week we will post more information about the process of conserving Nefrina’s mask.

Update from Abydos

Posted on June 12, 2013 by mollygleeson

A few weeks ago I wrote about Penn Museum Curator Joe Wegner and his team who are currently excavating in Abydos at the mortuary complex of Pharaoh Senwosret III. Recently the team has been battling exceedingly high temperatures and consistent loss of power (so no internet and water) but despite all of this, graduate student Kevin Cahail has been kind enough to continue sending me photos and information about their latest discoveries.

Many visitors to the Artifact Lab ask if mummies are still being discovered in Egypt. The answer is yes, and now I can point to the recent discovery of a mummy just outside of one of the tombs that was recently excavated.

View of the burial chamber from tomb CS.5

The shot above was taken after excavation of a tomb (named CS.5) – this is actually the same tomb that contained the curious bricks with the dots in them that I included images of in my last post. Excavation of this tomb revealed that the burial had been long-since removed, but soon after excavation, a skull, and then the rest of a body, was found in the sand nearby. It appears that she(?) was at some point thrown out of her tomb by robbers.

Removing and transporting unexpected or unwieldy archaeological finds often requires a bit of resourcefulness. In order to move this mummy into a box for transport back to the dig house, Kevin recovered an old laundry detergent sack, which they then slid under the mummy, and used as a sling to lift the mummy into a box.

Reconstruction of the skull of this mummy is now underway.

In addition to the field work, the team also spends time in the lab, which sometimes includes minor conservation work. This shabti figure was found in two pieces:

Kevin used Acryloid B-72, an acrylic adhesive commonly used in conservation for repairing ceramics (among many other things) to re-adhere the fragments:

Kevin holding the recently repaired shabti figure

As you can see, Joe, Kevin, and the rest of the team have been busy, and they only have about another week left in the field. As I hear more from them during their last days in Abydos, I will follow up with further information.