Natron

Have you checked out our FAQs page? We hear lots of interesting questions in the Artifact Lab every day, and we’re posting some of the more frequently asked ones on there, and providing answers when possible.

We recently added more information about natron to our FAQs-What is natron and what was it used for? Natron is a natural mineral consisting of a mixture of sodium carbonate decahydrate with sodium bicarbonate, sodium chloride, and sodium sulfate-essentially, a salt. Natron was an important part of the mummification process. It was used by embalmers to pack the body, which would help preserve the body by drying it out.

We are interested in observing the presence of natron on objects in the Artifact Lab. One of our mummies, for instance, has a very fine, white, crystalline substance in areas on its wrappings, particularly on the inside of the wrappings. Here is what it looks like:

An example of the white crystalline substance observed on the surface of the textile wrappings on one of our mummies.

And this is what it looks like under the binocular microscope:

That same crystalline substance magnified 7.5X

We also see this on some of the human remains in the lab. Is this natron? We’re hoping to investigate this further.

Read more about natron in the FAQs section of this site.

Happy Anniversary, Penn Museum!

Conservator Julia Lawson speaks to visitors through one of the Artifact Lab’s open windows

Yesterday was the Penn Museum’s 125th Anniversary! To celebrate the event, the museum held a free Open House, and the galleries were open from 10am to 10pm. In the Artifact Lab, we kept our 2 windows open all day, and conservators Julia Lawson and Nina Owczarek were busy all day speaking with visitors and answering questions. If you made it in yesterday, thanks for coming out to support the museum! If you didn’t, remember that we have open window periods every day that the museum is open, which are:

Tuesday-Friday 11:15am and 2:00pm and Saturday-Sunday 1:00pm and 3:30pm

Looking forward to seeing you in the Artifact Lab!

The mystery of the mummified heads

Another frequently asked question In the Artifact Lab is, “what’s the story with those mummified heads, and where are their bodies?”.

A disembodied, but completely wrapped mummified head in the Artifact Lab

Well, it is a bit of a mystery, and we don’t know why these heads are detached from their bodies, exactly.

We have 5 heads in the lab right now, all without any other remains. While two came in as gifts to the museum, the other three were collected by excavation, and all have been in the collection since the beginning of the 20th century. One, the head above, is still completely wrapped. The others are mostly, if not completely, missing their bandages but still have impressions of their linen wrappings and other residues from the mummification process remaining on the preserved skin, hair, and bones.

One of the unwrapped heads, showing evidence of the mummification process. In the Graeco-Roman Period, gold leaf was used to decorate parts of the body, as seen on this man’s head.

Close examination of these heads can provide some clues as to how they became detached. The head in the first image above, for instance, is still wrapped and there is a clean cut through the wrappings-this could not have happened by mistake or through deterioration-it had to have been cut off. Cut marks are also visible on another head-on both the bone and the preserved skin.

The wrapped head, showing the cross-section of the cut linen bandages around the neck. Human remains are preserved inside.

Why were these heads cut off? That’s also unclear, but it is very possible that the heads were severed as a result of looting. Bodiless heads have been excavated from tombs that clearly have been robbed and looting has been cited as the cause of these disturbed remains. Investigations in our archives may also reveal other clues-if we find anything we will provide an update!

While we may never be able to find out who these people were, there are things to discover from their remains-the heads can be CT-scanned in order to understand more about the mummification process (as seen in this study done at the MFA in Boston), determining sex if unclear, and possibly help in figuring out cause of death. DNA analysis may also be possible. Again, we will provide updates as we learn more. To read more about previous CT-scanning done at our museum on other Egyptian mummies, follow this link.

 

Ask the conservator!

Since the Artifact Lab opened on September 30, we (meaning my fellow Penn Museum conservators and myself) have spoken to hundreds of people who have visited the exhibit during our open hours (Tues-Fri @ 11:15am and 2:00pm, Sat-Sun @ 1:00pm and 3:30pm). Being the full-time conservator in the Artifact Lab, I get to talk to lots of our visitors, and I have to say that it has been one of the most fun parts of my job.

Chatting with visitors during a Q&A time in the Artifact Lab

I particularly love it when people ask me questions. Many of these questions are about Egypt-and because I am not an Egyptologist, I have spent a bit of time looking things up, asking our curators, and often saying “I don’t know, but I’ll see what I can find out.” We try to post answers to some of the frequently asked questions here on our blog, and we encourage you to ask questions via this blog well, by leaving them at the end of any of our posts, or in the comments box at the end of the FAQs page.

But many questions are about conservation, and this is an area that I can talk a LOT more about. One conservation-related question that I have heard a lot lately is “what are you going to use to repair that object, and will you use the same materials as the original?”. This is a great question, and gives me the opportunity to talk a bit about conservation decision-making and ethics.

There is a lot to consider when making decisions about how to repair objects and what materials to use. No two objects are exactly alike, so what works for one object may not work for another that is very similar.

One of the first things to consider is the nature of the object-what is it made out of and what is its condition (and why does it need conservation treatment)? We are always looking to choose treatment materials that are compatible with the original materials of the object and that will provide the strength, cohesion, etc. that the object needs.

That being said, we also use materials and methods for treatment that make our work easily distinguishable from the original object. For example, many conservation treatments involve filling losses in objects with new materials and coloring the fills to blend with the surrounding original materials. When carrying out this work, many conservators use an approach known as the rule of “6 Feet, 6 Inches”-meaning that when an object is viewed at 6 feet the repair is not visible but at 6 inches it is easy to distinguish from the original. We also document all of our treatments thoroughly in written reports and photographs, so that in the future it will be clear what has been done.

Another factor when choosing treatment materials is their long-term aging properties-we don’t want to use anything that discolors or becomes brittle over time (such as Duco cement) or will be very difficult, if not impossible, to remove later (like Elmer’s glue!!).

There is a LOT more to say on this topic, and as we put up new posts about ongoing projects we we will try to include information about the decision-making process. In the meantime-Ask the Conservator! Let us know if you have a question-either come visit us during our open window times or leave us a question here!