Poultices and Tourniquets: Medical Terminology in Conservation

by Tessa de Alarcón

Recently, while working in the Artifact Lab, I was reminded how often conservation borrows terminology from other fields, often in unexpected ways. Two great examples are the terms “poultices” and “tourniquets”. Both are medical terms, and kind of unusual ones. I recently used both methods on this ceramic lion relief (B20014) from the site of Nippur.

B20014 before treatment (left) and after treatment (right)

If you google “poultice” (which I just did) you would get some intriguing images of herbal substances on peoples’ skin sometimes with gauze in between (and sometimes not). A dictionary definition is “a soft, moist mass of material, typically of plant material or flour, applied to the body to relieve soreness and inflammation and kept in place with a cloth.”

Screenshot of a Google image search for “poultice”

In conservation, poultices are typically moist masses, but they are usually made of gauze, cotton, paper, or clay, and thankfully our objects don’t usually need relief from soreness or inflammation. Instead, poultices are usually used to draw foreign substances out, for example drawing out stains, soiling, or salts. These poultices can be moistened with all types of different solvents, depending on the treatment goal. In the case of the lion relief, I used cotton poultices to draw out ingrained sooty soiling to clean the surface.

Cotton poultice on the surface of the lion relief

Now if you google “tourniquet” you will find images of much more modern medical technologies, mostly of different types of straps. The dictionary definition is “a device for stopping the flow of blood through a vein or artery, typically by compressing a limb with a cord or tight bandage.”

Google image result for “tourniquet”

Since I don’t typically need to worry about museum artifacts bleeding, it might be difficult to imagine what this type of device could be used for during a conservation treatment. Tourniquets are often used in conservation as a controlled way to apply pressure and hold something in place. In the case of the lion relief, I used tourniquets made of cling film tightened around paint brush handles to hold the joins of the relief together and aligned while the joins set. The adhesive I used took a few weeks to cure, and until cured the adhesive did not have the tack or strength to hold the joins together without the support of a tourniquet.

Tourniquets holding the adhesive joins of the lion relief

One of the things I love about working in the Artifact Lab are the questions I get asked. I was recently working on the lion relief in the lab and realized that I had to explain the poultices and the tourniquets I used in this treatment. I use these terms so often, I had forgotten that for most people they mean something quite different.

The Golden Rule…of Conservation

By Tessa Young and Jen Mikes

Conservators love gold! Not only can it be worked with ease through a variety of processes to make beautiful artwork and jewelry, but it also never tarnishes or corrodes…not in 50 years or 5000 years – NEVER! When Queen Puabi’s headdress (ca. 2450 BCE) was excavated in the 1920s by Sir Leonard Woolley, her golden adornments were gleaming just as brightly as ever. You can learn more about Queen Puabi and her amazing treatment history here, and in the new Middle East Galleries.

Left: In situ image of the headdress of Queen Puabi, excavated by Leonard Woolley in the 1920s. Right: Puabi’s headdress on display in the new Middle East Galleries.

In the past few weeks, the Conservation Lab has been shimmering with gold. Williams Project Conservator Alexis North is preparing for the upcoming Mexico and Central America Gallery, treating gold pendants and ornaments. As a material, gold has virtually no inherent vices: it will not deform or crack with changes in relative humidity or temperature, nor will it discolor with age or UV exposure… it’s as stable a material as a conservator could ask for!  According to the American Institute for Conservation’s Wiki gold entry, “Under normal conditions, [ ] gold is incredibly stable and is more often susceptible to damage from mechanical pressures (scratching, distortion, etc.) rather than corrosion and other chemical processes.” Since conservators spend considerable amounts of time preventing and treating corrosion of less stable metals, the chance to work with largely inert gold objects is very exciting.


Gold frog ornament, SA2902, with a mend on its back proper right foot. https://www.penn.museum/collections/object/253831

Despite it’s notorious stability, each gold object was carefully documented and assessed for condition issues, as with everything that comes through the conservation labs. For most gold objects, the only treatment necessary is a brief campaign of degreasing with ethanol on cotton swabs. For others with thin and pliable areas, such as the back right foot of the golden frog ornament pictured above, external forces exerted on the material may cause stress cracks, potentially culminating in a break. Where cracks are seen, mends with toned Japanese tissue may be applied, creating inconspicuous band-aid-like fixes. After these quick treatments, the objects can often be returned to storage by the end of the day.

However, not all that glitters is entirely gold. Because gold is such a soft and expensive material, many “gold” objects are composed primarily of a harder and less expensive metal with just a thin layer of gold at their surface. There are several processes used to achieve this look. A number of the gold objects in the upcoming Mexico and Central America Gallery, including the golden frog ornament above, were manufactured using the technique of depletion gilding. Additional methods of gilding may be used to adorn metal or wood surfaces such as water gilding, oil gilding, acrylic gilding, or mercury gilding.

Another method for achieving the look of gold while reducing the cost or fragility, is by creating alloys (mixtures) of gold and other metals; a common example is white gold, which is composed of gold and nickel, palladium, platinum, and manganese. The inclusion of other metals in a gold alloy alters the properties of the gold, and may increase the hardness of the final material. However, the presence of non-gold metals in an alloy will predispose the material to tarnishing and discoloration.

To learn more about gold in Central America, check out this piece from the Metropolitan Museum of Art.