Student Guest Post: Leah Strayer on a Typical Day in the Mütter Bone Cleaning Lab

Over the summer, the Arch Street Project team was busy cleaning human remains.  The work was spread over three sites: The College of New Jersey, Rutgers-Camden, and the basement of the College of Physicians of Philadelphia (home of the Mütter Museum and Mütter Research Institute).  Quite a few students and volunteers worked with us on this monumental task.  The following post is from one such volunteer - Leah Strayer, a student from the University of Delaware.

A Typical Day in the Mütter Bone Cleaning Lab

by Leah Strayer, University of Delaware

Our morning begins at 10 a.m. when the volunteers for the day file into the Mütter Bone Lab.  Since the lab has been in operation, a number of staff, volunteers, and interns have given their time to help move the project along (*).  Recently, the regulars in the lab have been high school science teacher Kim Eberle-Wang, of Springside Chestnut Hill Academy, anthropology student Martha Kerbel, of Ursinus College, and anthropology student Leah Strayer (that’s me!), of the University of Delaware.

Our first task of the day is always to pack up and box the clean, dry bones from the previous day that had been drying overnight in the lab.  We wrap up each bone or clusters of bones in tissue paper and strategically layer them in the clean box, paying careful attention to the skull.  In addition to the bones, we also include items such as bone fragments and soil from the gravesite in the box.  The box is then labeled with the ‘G-number’ assigned to those human remains and stored for future transport.

Next we take some time to do a variety of data entry into spreadsheets to help us organize the plethora of data we’ve been collecting.  These data include any interesting observations that we made while cleaning a set of bones from the previous day, such as healed fractures or staining,and whether the mandible or lower jaw contains teeth which can be examined for the presence of dental calculi, a potential source of the individual’s DNA.

In addition to cleaning bones, we also have been examining some of the chemical properties of the soil from the graves. Taking soil pH measurements using a digital pH sensor is usually the next task of the day. We take repeated measurement of the soil pH and enter these data into a spreadsheet to calculate the average pH of the gravesite soil for each of the G-numbers we have worked on so far.  We are looking to see if there are variations in soil pH across the areas in which the graves were excavated. Variations in pH could be the results of environmental factors near the graveyard. There was a 19th century felt hat factory that was later built over a portion of this graveyard. Because acid was traditionally used to convert animal fur into felt, we are curious to see what the range of soil pH within these graves is and whether there is any correlation between pH and the condition of the bones and or the coffins.    

By this time, all of us are feeling pretty hungry and it’s time to break for lunch.  We join fellow Mütter staff in the lunch room and chow down!  In a room full of anthropologists and scientists, the lunch conversation is not of your typical workplace variety (try 18th century gynecological tools, for example!)

After our stomachs are full it’s time to get down to some serious bone-cleaning business.  The shelves in the Mütter Bone Lab are packed with boxes that contain human remains and material culture recovered from the Arch Street gravesites, each organized, of course, by G-number.  There is no methodical strategy of picking which box to work on -- whichever one “calls our name” is the one we pick. 

We take the bones out of their box and place them in a bin so that they are easier for us to access while we clean them (see image in this post).  At the bottom of the box there is often a mix of soil and bone fragments.  The bone fragments are too small and delicate for us to clean, so we designate a labeled paper bag for them, and we also collect the soil from the box.  Part of this soil is collected in a film-canister tube that will be used as a control for more detailed soil analysis.  The first step in the cleaning process is to dry-brush the bones.  We do this by using a wooden skewer to gently scrape off chunks of soil attached to the bone and then we go in with a dry toothbrush to dust off as much of the remaining soil as we can.  In the case that there is an intact skull, part of the cleaning process involves removing what is left of any brain tissue and setting it aside in its own bag.  Teeth and any remaining soft tissue attached to the bones are also set aside.  Any deformation or miscoloring of the bones is documented in written and photographic form as well.

The second step in the cleaning process is to wet-brush the bones.  Not all of the bones we’ve encountered have been able to be wet-brushed; it just depends on how brittle and fragile the conditions of the bones are.  For the bones that are durable enough to withstand wet-brushing they are brushed using a toothbrush that has been dipped in water.  Wet-brushing allows for the fine layer of soil that was left from dry-brushing to be completely removed from the bones.  It is important to not submerge the bones in water, as that can cause the outer layer of the bone to breakdown.  The wet bones are then placed on a stainless steel drying rack that is left out to dry overnight.

By this time the clock is inching its way towards 3 or 4 o’clock and our bodies are definitely feeling tired after 3+ hours of bone cleaning, and it’s time to call it a day. However, before we leave we clean up our workstation and do any necessary preparations for the next day.

(*) A total of twelve wonderful people have worked in the Mütter Bone Lab with us this summer (2018) and together we have completed the cleaning of fifty-seven sets of human remains. They include:

Mütter Bone Lab & Researcher Affiliation

Anna Dhody Curator of Mutter Museum, Director of Mutter Institute

George Leader, College of New Jersey

Kimberlee Moran, Rutgers University

Kim Eberle-Wang, Springside Chestnut Hill Academy

Ann Zalasky, Springside Chestnut Hill Academy

Sabrina Wang, Springside Chestnut Hill Academy

Bill Haotian Cao, Springside Chestnut Hill Academy

Leah Strayer, University of Delaware

Martha Kerbel, Ursinus College

Sabrina Kwak, Haverford College

Rachel Lightstone, Bryn Mawr College

Emmy Snider, Burnst McDonnell/ SNA International