Salvaging PUM I’s chest wrappings

This week, I started to work on the treatment of our mummy PUM I‘s linen wrappings. Poor PUM I – not only is his body quite deteriorated and in multiple pieces, but his linen wrappings are also fragmentary and very fragile. Some of linen in the worst condition are the pieces that once covered his chest, which were cut off during the 1972 autopsy.

This rectangular section of textiles was cut away as a single unit during the 1972 autopsy.

This rectangular section of textiles was cut away as a single unit during the 1972 autopsy.

In addition to the mechanical damage caused by the autopsy, the linen has suffered from insect damage and it is significantly stained and embrittled in areas, likely due in part to deterioration of the human remains they were once in contact with.

Removing the wrappings (left) and the chest wrappings after removal (right)

Removing the wrappings (left) and the chest wrappings after removal (right)

While this linen is in poor condition, it can be moved as a single unit, so we removed it for treatment. The goal of the current treatment is to keep the linen layers in this section together; to prevent them from slipping out of alignment and to prevent the linen from continuing to tear and deteriorate even more.

After vacuuming the linen thoroughly, I got to work relaxing distorted areas and realigning tears.

Local humidification of the linen in progress, using damp blotter and Gore-Tex

Local humidification of the linen in progress, using damp blotter and Gore-Tex

To realign tears, I bridged these areas from behind with small pieces of Japanese tissue paper, adhered in place with methylcellulose adhesive. The methylcellulose works well because it sets very quickly with only a small amount of pressure from my finger or a spatula.

One side of the wrappings before (left) and after (right) humidification and tear repair

One side of the wrappings before (left) and after (right) humidification and tear repair

The other side of the chest wrappings before (left) and after (right) tear repair

The other side of the chest wrappings before (left) and after (right) tear repair

This is only the beginning of the treatment on PUM I’s wrappings, but I think they are already looking better!


Giving our falcon a little love

One of my favorite artifacts in the lab is a falcon mummy, which I described in an earlier post. While he is a fascinating object, this poor little guy hasn’t been able to be exhibited, or even handled very much, because some of his linen wrappings are quite deteriorated, brittle, and breaking apart, causing serious structural issues.

Overall shot of our falcon mummy

Recently, I worked to stabilize the linen wrappings on his feet, which were partially detached, and in some areas, barely hanging on by a few threads.

Side view of the falcon’s “feet” showing the fragile, partially detached linen wrappings

Before carrying out any treatment, I did a little bit of research and carried out some testing to determine what materials I might want to use to repair the textile. I knew that a stitched repair would not be possible, as the linen fibers are far too weak and this would likely cause further damage, so I started investigating different adhesives and support materials to use instead. As part of this process, I consulted with Nancy Love, a local conservator in private practice who specializes in textiles. Nancy recently visited me in the Artifact Lab, and among the other materials I was trying, she suggested that I experiment with nylon bobbinett, a heatset nylon net.

I did some experimentation with it, and I really liked how it behaves, both as a support fabric and as an overlay to protect fragile areas-it drapes well and can be toned easily with dyes or paint. After feeling satisfied with the results of some of my tests, I set out to repair the damaged linen over the falcon’s feet.

I started by toning the bobbinett with Golden acrylic paint. Then I backed the fabric that was dangling off the back of the foot with the toned bobbinett lightly coated with 10% methylcellulose in water. I then used the bobbinett support fabric to raise the partially detached fabric up into place, secured temporarily with pins.

After positioning the linen, I covered the entire back of the foot area with another piece of toned nylon bobbinett.

The back of the foot area with an overlay of the toned nylon bobbinett, after treatment

Finally, I tacked down the strip of linen over the top of the feet, which was also partially detached but otherwise fairly stable, using small beads of methylcellulose. Reattaching the linen over this area also hid the edge of the nylon bobbinett overlay.

View of the front of the foot wrappings, after treatment

I’m pleased with the results, and I can now breathe a sigh of relief that we’re not going to lose any more of the linen from this area. My next task will be to address the falcon’s partially detached head/neck area. Hang in there, little guy!


More pieces of PUM I

We are continuing to work on our mummy PUM I (more interesting details on him here) and last week, our new intern, Melissa Miller, and I removed a plastic bag that had been placed in his chest cavity, presumably after his autopsy in 1972.

The plastic bag inside PUM I’s chest, before removal

In this plastic bag, we are finding large pieces of linen from his inner and outer wrappings-some of these pieces also bear impressions of the beaded shroud that once lay over his body.

The plastic bag after removal, filled with textile fragments

It is evident that these pieces of fabric were cut away (and some probably fell off) and removed during the autopsy, and they were placed in this bag and then inside the chest to fill this area out a bit after the procedure.

In this process, we also decided to remove the upper portion of the wrappings over PUM I’s chest – they were completely cut off during the autopsy and then replaced, to make him look whole again. Once we determined we could safely lift them away from the rest of the body, we decided to go for it!

The detached wrappings from PUM I’s chest area, after removal

Removing this large segment of wrappings will allow us to better examine their condition, and also to examine the condition of the textile wrappings on the other side of the body, which are now partially visible. There are lots of other interesting, and unexpected things that we’re finding, and other great shots to share – we will continue to provide updates!


Polarized Light Microscopy

Our Conservation Department recently purchased a Zeiss polarized light microscope-”the best microscope on campus” according to the specialist who set it up for us, and who is knowledgeable about the other scopes in use at Penn. Having the nicest equipment around isn’t familiar territory for conservation labs, so we’re enjoying having this status, but more importantly, having such a nice piece of equipment to use.

Our new microscope installed in the Artifact Lab

Polarized light microscopy (PLM) is used for examination of specimens in many types of laboratories, including biology and geology labs. In conservation, we use PLM for identification of minute fragments from objects-anything from pigment particles to wood fragments to textile fibers. We also use this technique to examine corrosion products, salts, and other materials found on artifacts-all of this work helps us better understand what the objects are made of, their condition, and ultimately provides important information for making conservation treatment decisions.

For example, our Conservation Fellow Tessa de Alarcon, who is conducting a year-long condition survey of Penn Museum artifacts from Kourion, Cyprus, has been using PLM to examine salts present in ceramic vessels from this collection. Tessa is desalinating the ceramics to remove the salts, which likely accumulated in the ceramics in the burial environment and will cause damage if not removed. To confirm which salts are present, she removed samples of the salts and examined them under the microscope. Here is an image of one of the salt samples, which shows that there are 2 different types of salts present-nitrates and sulfates.

Magnified image of 2 types of salts present on a ceramic vessel from Kourion (400X magnification).

You can read more about Tessa’s work with the Kourion collection (and view a cool video clip!) here on the Penn Museum blog.

In the Artifact Lab, one of the first ways that I’ve used our new microscope is to examine fibers from a thread that detached from the fabric wrappings of the falcon mummy I described in a previous blogpost. Fortunately for me (but unfortunately for the poor falcon mummy!) there are lots of detached threads that were available to sample for examination under the microscope. Here is a magnified image of one of these threads:

A small detached thread from the falcon mummy’s wrappings (40X magnification). I noted that the thread has an “S” twist and the fibers are shiny.

Using our binocular microscope, I put a drop of water on the thread and teased out several individual fibers from the thread on a glass slide, and then covered the fibers with a cover slip.

This image shows all of the tiny fibers from the larger thread-it is important to examine these fibers individually in order to identify what type of textile the falcon mummy is wrapped in (40X magnification).

Once the slide was prepared, I mounted it on the polarized light microscope and examined it at 50, 100 and 200X magnification.

Fiber from falcon mummy textile wrappings (200X magnification)

Under such powerful magnification, it is possible to see features such as a very small lumen (central cavity) and nodes along the length of the fiber. These features are characteristic of flax fibers, and comparing my sample with known references (including in this great Fiber Reference Image Library), it was immediately clear that this is what it is. Flax is used to make linen, and since the majority of ancient Egyptian textiles are linen, I already had a good idea that this is what was used to make the falcon mummy-but this proves it!

You can see from this work that PLM is a very useful technique, but it also is important to have an idea about what the possibilities are for what your sample-background research and close examination before microscopy is essential.