Most museums, mine included, have far more artifacts than they can display all at once. So, the artifacts which are not in display are kept in the museum’s collection room. Here they are stored in fairly stable environment conditions, which help to preserve them. However, even under ideal conditions there can still be issues which arise. This is why I routinely monitor the artifacts there. So, when I recently discovered some whitish spots all over a large leather medical trunk, I was not at all pleased!
|This leather trunk, or pannier, was used to transport medicines and medical supplies in the Civil War. You can see the areas of white haze on the exterior.|
|Things looked even worse when I checked the interior. It looked a lot like mold!|
I took the pannier from the collection room to my conservation work room, partly in preparation for removing the mold, but also to protect the rest of the artifacts in the collection room from the mold. Knowing that mold spores are airborne and had probably already spread through the collection room was not a pleasant thought for me though! However, after doing some research I discovered that it was not mold after all, but was actually “fatty spew” or “fatty bloom.”
Fatty spew occurs when the fats and oils in the leather migrate to the surface. Spew can be caused by issues during the tanning process of the leather, or from the application of leather products which contain oil or grease, or from environmental conditions, especially a drop in the temperature. So, next I researched ways of getting rid of the spots. I found a number of suggestions, but ultimately decided to try the gentlest and least-invasive method first – wiping the surface with a clean, damp sponge.
|The interior looks much better now!|
|This pannier has been stored with an acid-free insert to help stabilize the pannier. The lid is the biggest concern since it otherwise would have nothing underneath to support its weight. Leather can sag over time, and this helps to prevent that.|
I understand from my research that the fatty spew can possibly return. So, I will be keeping a closer watch on this pannier. If that happens I can try some different things, but I will first see if this simple fix does the trick.
|Back on the shelf in the collection room, where it belongs!|
To see three different medical panniers from the Civil War, click here.
Photos courtesy of the National Museum of Civil War Medicine.