Boxes in the Attic

As some of you blog may know, the biggest project currently being done at the Peabody is the complete inventory of all of our collections. In previous blog entries (these can be read here and here), we have discussed the process, including the fact that we move the artifacts from the original wood storage drawers to custom made gray Hollinger boxes-generously supported by the Abbot Academy Fund. When we received the shipments of these boxes, they were stored off-site in two storage units that the Peabody had rented in town. These two storage units perfectly held all of our boxes and everything has been right in the world.

Image of new storage cartons and old wooden storage drawers.
Side by side comparison of new gray boxes and older wooden drawers.

A few weeks ago, I was up in the attic of the Peabody doing a pest inspection with Waltham Services and I had an idea. I went to my supervisor Marla Taylor and I said, “Do you know what would be an interesting idea? If we rearranged what is up in the attic, closed out both storage unit accounts and moved the rest of the boxes up into the attic.” By this point in time, the first of our two storage units was getting pretty empty, with maybe 15-20 large boxes remaining inside. I told Marla that if this idea worked out, it would benefit the Peabody in two major ways (and possibly more, but these are the big ones).

First of all, we wouldn’t have to pay the monthly fee for storage units anymore. This would ultimately save the Peabody a chunk of change every fiscal year, and who doesn’t want to save money wherever they can? When we had the storage units, we used to have to reserve a rally wagon (an SUV owned by Phillips Academy that only certified drivers can operate) and drive over to the storage unit. With that method we could only fit a maximum of six boxes (each containing 12 gray boxes) into the back of the SUV. Additionally, we would save on the cost of renting the rally wagons, which we have been using more frequently lately since we have three people working on the inventory.

Second, anytime we needed more gray boxes for the inventory, we would be able to just walk upstairs to the attic and grab them. The only way this idea wouldn’t work was if the boxes wouldn’t fit in the attic. Marla thought about this idea for a minute and we had a look around the attic to see if this was feasible. After a few minutes with a measuring tape, she said she thought that this idea was great and had serious potential to work. This response was of no surprise to me, because it is well known that I only have good ideas. I received yet another gold star for my many efforts and great ideas.

My Gold Stars
These are my gold stars for all the good ideas I have come up with. I cherish them.

We then strategized how to get the Peabody ready for the influx of these boxes of boxes.  First, we needed to empty the first storage unit. This involved John and Emily making multiple runs to the unit while Marla, Emma and I unpacked the gray boxes and organized them around the basement. All of these gray boxes managed to fit in various places downstairs. This was great! It meant the attic wouldn’t have to house anything but the second unit.  A week before the big move, we set about cleaning the attic to make as much space as possibly for the contents of the final storage unit. With the help of work duty students, Marla, Emma, Emily and John, the attic was cleaned and looked like a barren wasteland, but a beautiful one that was about to be filled with boxes.

Finally, we rented a U-Haul truck and set to work.  We had set aside an entire day to facilitate this move. Marla and John drove the truck to the storage unit and filled it with as many boxes as possible. When they pulled up outside the Peabody, all hands were on deck. We got all of the boxes into the lobby and started carrying them up to the second floor landing. Marla and John left to go fill the truck with a second load. Once all of the boxes were up on the second floor, Emily, Emma and I started the move to the attic. This part seemed like it was going to be difficult because the attic stairs are very narrow and the large boxes are very wide. But then, I had the BRILLIANT idea to use the stairs as a ramp and literally push the boxes up the stairs. This made the operation go so much faster than originally anticipated.

Boxes in the Attic 1
Seriously, look at how great these boxes look in the attic.

When all was finally said and done, this move that we expected to take all day (and possibly longer) was accomplished in THREE HOURS. GO TEAM – these boxes were MEANT to go into this attic. We were exhausted, but totally deserving of the Indian Buffet lunch we decided to enjoy. The day was a huge success for the Peabody Collections team. Now the attic looks beautiful and it will be much easier for us to restock on boxes when we need them.

Abbot Academy Fund continues to support the Peabody Institute

Contributed by Marla Taylor

Have you ever heard of the Abbot Academy Fund?  (if you said “yes” from one of our earlier blog posts – Gold Star!)  If not, please allow me to introduce them.

One of the first educational institutions in New England founded for girls and women, Abbot Academy opened its doors in 1829 and flourished until Abbot Academy and Phillips Academy merged on June 28, 1973.  At that point, the Abbot Academy Fund (AAF) was established with $1 million from the Academy’s unrestricted funds.  The fund operates as an internal foundation with its own board of directors.  Its goal is to preserve the history, standards, tradition, and name of Abbot Academy by funding new educational ventures at the combined school.

The Abbot Academy Fund has been a foundational supporter of the Peabody Institute, especially in recent years.  With grants going back to 1990, the AAF has given the Peabody over $250,000!  I was recently reminded of this incredible generosity when the AAF once again provided support to complete the transcription of the Peabody’s original accession ledgers.

Looking back over all the successful grants, the AAF has supported a real variety of projects at the Peabody – everything from exhibition support to object conservation to equipment purchase to expeditionary learning trips.  However, the largest portion of their patronage has gone to support cataloging and rehousing the collection.  They provided funds to purchase a server in 2014 to allow for an online catalog.  And again in 2016-2018 to acquire the boxes needed to rehouse the artifacts and gain physical control over the collection.  All told, the AAF has awarded us over $100,000 in the last ten years!

Basically, the Peabody Institute would not look or operate the way it does now without the incredible support from the Abbot Academy Fund.  I can’t thank them enough!

So much work at the Peabody is brought to you by a grant from the Abbot Academy Fund, continuing Abbot’s tradition of boldness, innovation, and caring.

Introducing Our Newest Team Member

Contributed by Emily Hurley

My name is Emily and I have been working as the new Inventory Specialist at the Peabody Institute for about a month now. My job is to assist with the current inventory and rehousing project. My day to day work consists of moving artifacts from their old wooden storage drawers into new archival boxes which better preserve the objects.

I grew up in a small town called Andover, New York (I know, how ironic) before moving to Buffalo to pursue my Bachelor’s degree in Anthropology. From there, I spent a year in Florence, Italy doing coursework for my MA in Museum Studies which I completed this past August. During my time in Italy, I learned collections care and management from some of the most famous museums in the world including the Uffizi Gallery and the Vatican Museum. This is only my first position working in a museum but I have completed museum internships back home in Buffalo as well as in Santa Fe, New Mexico.

Emily Hurley photo
This is me overlooking the beautiful city of Florence!

I have always been passionate about archaeology and indigenous studies so I am excited to be in a position where I can apply my knowledge of both and continue to learn more. Even though I have only been here a few weeks, I have learned so much already. It is amazing to be able to work with and handle objects every day which are hundreds of years old and come from all over the continent. Objects that I have been studying for the past five years are now a part of my everyday life and it is truly such a rewarding experience.

Overall I am very excited to be in this position and can’t wait to see what else I will learn and do during my time at the Peabody!

Wild Ride No More

Contributed by John Bergman-McCool

Cups and Coaster
The collections environment before and after rehousing in archival boxes

Back in March I wrote a blog post summarizing efforts to rid collections objects of mold and salt uncovered during inventory and rehousing. We identified and isolated affected objects and cleaned them by dry brushing and vacuuming. The cleaned objects were rehoused in archival boxes that included a sachet of silica gel. The purpose of the gel is to reduce relative humidity (RH), thereby robbing mold and salt of the environmental conditions necessary for their growth. To better understand what the environment is like inside the boxes, we are monitoring their temperature and relative humidity with two data loggers. One is placed inside a box without silica gel and one is placed inside a box with silica gel. These conditions will be compared against a data logger that is recording general conditions in the basement not far from where these test boxes are located. We will be watching these data loggers over the coming year, but we already have some interesting results.

Temp and RH graph for John August 2019
Environmental Stats for April

First, the boxes are working well as a buffer against relative humidity cycles. The graph above shows RH and temperature for the month of April; the basement is shown in red and the boxes with and without silica are blue and yellow, respectively. In April the RH in the basement was quite volatile. However, the RH inside the boxes is remarkably tranquil in comparison. The boxes are exhibiting small daily shifts of 1 or 2%, which is acceptable. Keeping RH from shifting dramatically is an important factor in collections care. Organic materials such as basketry, bone, and wood are hygroscopic, meaning that they can absorb and release moisture in the air. Rapid and large changes in RH can cause organic materials to swell and contract leading to damage such as cracking or delamination. It is best to keep collections from experiencing RH shifts exceeding 10% over a given month and on that count the boxes are doing a great job. As they are found, the most sensitive organic collections are being moved to another part of the museum that has a better environment.

Layerd Storage
Layered Storage

The National Park Service recommends creating a layered approach to collections storage. Every enclosure within museum storage can act as an environmental buffer. The first enclosure is the building itself. It may seem pretty obvious, but keeping collections inside a building greatly reduces the effects of environmental factors. The same is true of every subsequent layer of enclosed storage. Here at the Peabody Institute we have wooden storage bays that, when closed, serve as another layer. The archival boxes act as a final layer.

 

Interestingly, the basement seems to be effective at buffering daily temperature cycles. The temperature in the basement has been hovering around 70 between February and June leaving little for the boxes to mediate.

Sachet
Silica Gel Sachets

The second finding of note is that the sachets of silica gel were spent faster than anticipated. As mentioned above sachets of silica gel were placed in the boxes with cleaned objects. The gel, in solid pebble-like form, starts out orange and as it absorbs water it changes to a deep blue. The expectation was that the gel would keep the RH at a reduced and steady level. The graph above shows that the silica gel was keeping relative humidity lower than that of the box without gel, but it is only a matter of a few percentage points. Most likely the boxes are not well enough sealed for the silica gel to more significantly moderate RH levels. The silica was active from mid-February until mid-April (see star on graph) when RH graphs inside both boxes started to match almost perfectly. A visual inspection in June indicated that the gel was spent. We replaced the silica in mid-June and it was spent within two weeks given the higher RH levels generally in the basement.

 

Our data shows that the boxes are acting as a significant buffer against potentially damaging cycles of increasing and decreasing RH levels. For now, we are forgoing replacing spent silica gel. Later in the fall we’ll see how the archival boxes work with our dehumidifiers at keeping mold and salt inducing RH at bay.

Halfway there…and funding for the finish!

Contributed by Marla Taylor

I am thrilled to share that we have officially inventoried half of the collection!

As of mid-June, the collections team has inventoried 1,079 artifact drawers – half of the 2,159 that hold our collection.  Those drawers translate to 243,967 individual artifacts that have been counted and rehoused in the process!

A massive “thank you” goes out to all of the staff and volunteers who have contributed to the inventory so far: Rachel Manning, John Bergman-McCool, Emma Cook, Annie Greco, Alex Hagler, Quinn Rosefsky, and dozens of work duty students.

With excitement and deep gratitude, we also announce that funding has been secured to complete the inventory by our target deadline of December 31, 2020.

The Oak River Foundation of Peoria, Illinois has renewed its support for a temporary inventory specialist for another two years.  Our deepest appreciation goes to the Oak River Foundation for its continued generosity and commitment to the Peabody’s goal of improving the intellectual and physical control of the museum’s collections.

But that is not all!

Barbara and Les Callahan have agreed to provide critical funding to extend the appointment of our current inventory specialist – John Bergman-McCool.  Les graduated from Phillips Academy in 1968 and is an active volunteer on campus. Barbara has served on the Peabody Advisory Committee since 2013.  Both have been steadfast advocates and supporters of our mission and we cannot thank them enough for providing this deeply meaningful gift.

We hope these acts will inspire others to support our work to better catalog, document, and make accessible the Peabody’s world-class collections of objects, photographs and archival materials. If you would like information on how you can help, please contact Peabody director Ryan Wheeler at rwheeler@andover.edu or 978 749 4493.

Calling All Volunteers!

Have you ever wondered what it would be like to work in a museum? The Peabody, like many museums, has a small force of volunteers who dedicate a few hours each week to helping our staff further our work. We are currently looking to expand this group of volunteers.

Our volunteers have assisted us with a huge number of projects. We currently have one volunteer who works with our textile collection. In a museum setting, it is very important to protect artifacts from pests that can occasionally work their way into the building. Our textile artifacts are particularly susceptible to the damage from carpet beetle and clothes moth larvae. An infestation of these pests can completely destroy a textile collection without proper intervention and pest management. In order to stay on top of any potential pest problems, one of our volunteers systematically goes through our textiles and inspects them for evidence of damage, insect excrement, and live specimens. This involves vacuuming the textiles, inspecting them, and putting them through a freezing process designed to kill living pests. Once this two week process is completed, the textiles are removed from the freezer, isolated, and then inspected again for any signs of life. Once we are satisfied that pests are not present, the objects are returned to the collections storage space. Our volunteer has done an excellent job with this, and has made significant process on this project.

Our other current volunteer is a P.A. alumnus who works on a wide variety of projects. One of the most important projects is our complete inventory of the collection. We hope to renovate the Peabody in the next few years and before we do that, we need to have a completed inventory of our collections. This involves inventory of our storage drawers and recording information about collections, including objects present, count, geographic origin, and current storage location.  Volunteers can help with this most important project.

In addition to helping out with the inventory, volunteers help out as needed across the Peabody. Other projects include organizing portions of the archives for researchers, pulling out and putting away objects for classes, creating labels for our artifact boxes, and transcribing catalog cards into a digital system. There is never a shortage of work to be done at the Peabody!

If this sounds like an opportunity that you would be interested in, feel free to contact me with for more information at rmanning@andover.edu. I would be glad to speak to anyone about potentially volunteering for us!

Fowled in Collection

Contributed by Marla Taylor

This skeleton is from a site near Glorieta, New Mexico – just southeast of Santa Fe – and collected by Alfred Kidder during his work at Pecos Pueblo.

As discussed in a previous blog, The Macaw Factor, the presence of macaws in the southwest is certainly note-worthy.  These birds have a natural habitat approximately 1000 miles to the south and were clearly transported to the region as status symbols.  They may have been kept for their feathers or displayed as a sign of wealth and connections.

Two scarlet macaws
Scarlet macaws

As we continue to move through the collection, who knows what we will find next!

Further reading:

Hill, Erica. “The Contextual Analysis of Animal Interments and Ritual Practice in Southwestern North America.” Kiva 65, no. 4 (2000): 361-98. http://www.jstor.org/stable/30246334.

Wu, Katherine J. “A Macaw Breeding Center Supplied Prehistoric Americans With Prized Plumage.” Smithsonian.com, August 13, 2018.

 

Half-Life: Radiocarbon Dating Tehuacán Carbon Samples

Contributed by Emma Cook

In my last blog I discussed soil analysis and its importance in dating and understanding a site. Another form of analysis used in the Tehuacán Archaeological-Botanical Project by Richard “Scotty” MacNeish was a process called radiocarbon dating, a technique developed by University of Chicago physicist Willard Libby. Carbon samples were collected during excavation and sent for carbon dating to be used for the Tehuacán Chronology Project.

There are two techniques for dating in archaeological sites: relative and absolute dating. Relative dating, in a stratigraphic context, is the idea that objects closer to the surface are more recent in time relative to objects found deeper in the ground. This relates to the law of superposition, which in its plainest form, states soil layers in undisturbed sequences will have the oldest materials at the bottom of the sequence and the newest material closer to the surface. Although this form of dating can work well in certain cases, it does not work for all.

Jars of Carbon Samples from various sites in the Tehuacán Valley.
Jars of Carbon Samples from various sites in the Tehuacán Valley.

Many sites include soil layers that have been disturbed and this can happen several ways. Natural disasters, such as floods, can erase top layers of sites. Rodents can move around layers in a site as they burrow underground, sometimes moving items from one context to another. Even current human activity can change the stratigraphy of a site through construction, post holes, and pits.

This takes us to our second dating technique. Absolute dating represents the absolute age of a sample before the present. Examples of objects that can be used to find absolute dates are historical documents and calendars. However, when working in an archaeological site without documents, it is hard to determine an absolute date. If a site has organic material present, radiocarbon dating can be used to determine an absolute date. Radiocarbon dating is a universal dating technique that is used around the world and can be used to date materials ranging from about 400 to 50,000 years old. Radiocarbon dating may even work on very recent materials.

Part of this carbon sample sent to Isotopes lab for radiocarbon dating.
Part of this carbon sample sent to Isotopes lab for radiocarbon dating.

Organisms such as plants and animals all contain radiocarbon (14C). When these organisms die, they stop exchanging carbon with the environment. When this occurs, they begin to lose amounts of 14C overtime through a process called radioactive decay. The half-life of 14C is about 5,730 years. Radiocarbon dating measures the amount of stable and unstable carbon in a sample to determine its absolute date. As a result, the older the organic material, the less 14C it has relative to stable versions of the isotope.

The carbon samples recovered from the Tehuacán Valley were collected specifically with this in mind. Many of these samples had labels or notes stating that some of each sample was sent to labs for radiocarbon testing. The carbon samples are organic material and their properties of radiocarbon were used to determine the age of the material, which in turn, helped date each site.

Map of the Tehuacán Valley and some of the sites the carbon samples came from.
Map of the Tehuacán Valley and some of the sites the carbon samples came from.

The following sites are represented in some of the jars of carbon samples I catalogued from the Tehuacán Archaeological-Botanical Project.

Site Number                        Site Name                     Radiocarbon years

Tc 35                                         El Riego                                 6800 to 5000 B.C.

Tc 50                                         Coxcatlan Cave                  5000 to 3400 B.C.

Tc 307                                      Abejas                                     3400 to 2300 B.C.

Tc 272                                      Purron Cave                          2300 to 1500 B.C.

Ts 204                                     Ajalpan                                     1500 to 800 B.C.

These results were published in Volume Four of MacNeish’s Prehistory of the Tehuacan Valley: Chronology and Irrigation and can be found on Page 5. MacNeish and Tehuacán Chronology Project director, Frederick Johnson, selected carbon samples to be sent for testing, which resulted in the determination of 218 radiocarbon dates. Johnson played a prominent role in radiocarbon dating, serving as the chair of the Committee on Radioactive Carbon 14 set up by the American Anthropological Association. This project not only produced a chronology for the Tehuacán sequence of excavated sites, but later contributed (along with 400 additional radiocarbon dates) to the chronology for all of Mesoamerica. The dates, however, were made within the first two decades of radiocarbon dating and lack the accuracy and precision now available with newer techniques, especially with the older dates.

To read more about the Tehuacán Archaeological-Botanical Project and the Tehuacán Chronology Project visit Internet Archive.

Further Reading

Libby, Willard F. Radiocarbon Dating, 2nd ed., University of Chicago Press, Chicago, IL, 1955. Print.

MacNeish, Richard S. et al., The Prehistory of the Tehuacan Valley: Chronology and Irrigation. Vol. 4. University of Texas Press, Austin, TX, 1972. Print.

Stromberg, Joseph. “A New Leap Forward for Radiocarbon Dating.” Smithsonian.com, October 18, 2012. Web. https://www.smithsonianmag.com/science-nature/a-new-leap-forward-for-radiocarbon-dating-81047335/

Taylor, R.E. and Ofer Bar-Yosef. Radiocarbon Dating: An Archaeological Perspective. 2nd ed., Routledge, New York, NY, 2016. Print.

The Dirt on Soil Analysis

Contributed by Emma Cook

My latest work for the Peabody Inventory and Rehousing Project has led me to Tehuacán, where I have been cataloguing glass jars that contain soil samples. These jars are a part of the Tehuacán Archaeological-Botanical Project by Richard “Scotty” MacNeish during the early 1960s. The samples were collected for testing and analysis purposes from the project area. When archaeologists excavate a site, they dig through soil layers formed by the activities of past people. What archaeologists recover from these layers provides clues about what happened at that site from features or artifacts. However, the actual soil is another very important clue for archaeologists, as it can help date sites and tell a lot about the environment of the site during the time the soil layers were formed.

Soil blog_pic2
Jars of Soil Samples from the Tehuacán Archaeological-Botanical Project, 1960s

Giving an accurate description of soils help archaeologists better understand what happened in the past at a site. The color and texture of soil can reveal the age of an archaeological site, as well as how the site was used. For example, a circular stain in the soil may reveal a post-hole deposit, indicating that there was once a wooden post that had decayed, leaving a soil discoloration in the ground. Depending on the site, these post-holes could represent a structure or palisade. In addition, studying soil fertility can help archaeologists understand ancient agricultural systems.

Soil blog_pic3
MacNeish (left) and a field assistant analyzing stratigraphy at the Gladstone site on Kluane Lake in the Yukon.

Archaeologists use the Munsell Color Chart to help them describe the colors of the soil layers in a standardized way. This system was developed by Albert H. Munsell at what is now MassArt in 1905. Archaeologists compare the soil color in their excavation units to the color chips of the Munsell Chart – similar to the color squares found in hardware stores for paint. Where a color may be brown to one person, it may be gray to another – so it is important that archaeologists use this chart so they can standardize their descriptions.

Munsell Color Chart
Munsell Color Chart

To describe soil textures, archaeologists and geomorphologists use a soil triangle to help them determine what type of soil they are examining in the field. There are three types of soil components: sand, silt, and clay. Most soils have a combination of these three components and each of these components vary in sizes – sand particles being the largest and clay particles being the smallest. Similar to how the Munsell Color Chart describes soil color the same way, the soil triangle helps archaeologists describe soil texture consistently.

Soil blog_pic5
Soil Triangle – Courtesy of the United States Department of Agriculture

Another way archaeologists analyze their site is through soil stratigraphy. This is the different types of strata, or layers of soil that archaeologists examine to map out the archaeological site over time. Stratigraphy can be used to determine which soil was associated with human occupation and which layers are sterile, meaning the soil is not associated with human occupation and does not contain any archaeological material. Layers that include artifacts and features represent a place where people lived and worked, as archaeologists can see the objects left behind by human activity. Sterile layers such as subsoil, flood sediment, and bedrock are not as distinct, but provide information on a site’s activity or inactivity.

Soil blog_pic6
Archaeologists mapping out the stratigraphy at Purron Cave, TC 272, in the Tehuacán Valley.

The jars of soil samples were most likely examined after excavation and retained for further analysis. Presently, these soil samples have been rehoused and cataloguing for each of these jars is complete. To learn more about Richard “Scotty” MacNeish and the Tehuacán Archaeological-Botanical Project, visit the Peabody’s online archival collections. The MacNeish archives are available for research, separated into two collections – the Richard S. MacNeish Papers and the Richard S. MacNeish Records.

 

Further Readings

Birkeland, Peter W. 1974. Pedology, Weathering, and Geomorphological Research, New York: Oxford University Press.

Limbrey, Susan. 1975. Soil Science and Archaeology. London and New York: Academic Press.

Solecki, R. 1951. Notes on Soil Analysis and Archaeology. American Antiquity, 16(3), 254-256.

Uninvited Guests

Contributed by John Bergman-McCool

Mold_Salt 1
Meet Mold and Salt

In early February we wrapped up inventorying and rehousing collections that originated in Missouri. The work was followed by two weeks of cleaning, and as a result we’ve completed one of the regions held in the collection. So you may be wondering what we were cleaning. During the inventory, we encountered bone and antler objects covered with salt crystals and patchy dormant mold. The objects were cleaned before they were stored inside their new boxes to remove salt and minimize the risk of mold spreading to unaffected objects.

Where did the mold and salt come from and why are they a problem?

Mold spores are found everywhere in the environment. When the humidity is high, those spores germinate resulting in mold. Because it is a living organism, mold is classified in the museum world as an agent of biological deterioration. It eats organic matter, in this case the dust resting on the outer surface of bone or the bone itself, and secretes waste that can stain or damage the surface that it is growing on. Mold can appear to be dormant, but when the conditions are right mold will generate spores that are easily borne on the wind, allowing it to spread quickly.

Mold_Salt 2
Agents of deterioration

Salts on the other hand are considered chemical agents of deterioration. They are brought into museum collections on the objects themselves.  Dissolved salts present in groundwater can be absorbed by porous objects, such as bone, while they are buried underground. After the water evaporates the salts are left behind. Excessively humid conditions can dissolve soluble salts, allowing them to move through porous objects. When they arrive at the surface they form crystals. If the crystals form below the surface they can exert enough force to cause damaging cracks and spalling.

Mold and salt thrive in damp environments where the Relative Humidity (RH) is above 65%. The institute’s storage area is located in the basement, which does not have a controlled climate, so mold and salt are an unfortunate reality. Currently, the RH in the basement is somewhere below 15% (15% is as low as our monitoring equipment can read). RH levels this low shouldn’t support active mold and salt growth, so what we found is inactive, but it is hard to say when and for how long the growth of mold and salt was last active.

At the Peabody we are committed to maintaining the longevity of this very important research collection and salt and mold pose a risk to its scientific viability. Damage to the surface of artifacts caused by mold and salt can negatively impact the research value of the collection.

How do we prevent mold and salt?

While we don’t have an HVAC system maintaining the environment in basement storage, we have adopted a few practices that will mitigate and prevent future growth of mold and salt. First, we use dehumidifiers during times of high humidity that typically arise during the summer. Second, we are moving the artifacts currently stored in open drawers and rehousing them in closed archival boxes. The enclosed space of a box helps create a buffer that protects the contents from rapid shifts in RH that lead to mold and salt growth. The boxes will also keep future mold growth from spreading; something that was not possible with open-drawer storage.

Mold_Salt 3
Vacuum defeats Mold and Salt

In addition to the rehousing, we have implemented a cleaning program. When mold and salt are identified we isolate the effected object to keep spores from spreading. We clean the affected artifacts with a dry brush and vacuum. After we clean we use sachets of silica gel to absorb excess moisture, thereby providing another buffer against cycles of RH increases and decreases. In six months we’ll check on the status of the bone to see if the mold and salt are staying away.