Uhu and Pattex did not exist. In the 18th century, many households still made their own glue and were inspired by recipes from magazines and books. Also in the childhood home of George Washington, the first president of the US, researchers found dishes that were patched with homemade glue. An analysis of the pieces shows which materials people used.
To find out from which ingredients family Washington touched their glue in the years 1738 to 1772, the researchers have now tried to cook some recipes from the time. The ingredient lists had it sometimes in itself.
Some recipes could not have been replicated at all because ingredients such as bull's blood or "white slime from big snakes" were hard to come by, report the scientists around Mara Kaktins of the George Washington Foundation and Ruth Ann Armitage of the University of Michigan in an article the year 2016.
Garlic glue was especially efficient
The patched harness from George Washington's childhood home was discovered a few years ago, but the results of the investigation of the adhesives are so far barely known to the general public. Armitage once again reported research in February 2019 at the AAAS Science Conference in Washington.
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After rejecting the prescriptions with bull's blood and snake slime, the researchers initially tested rather simple mixtures. The adhesives are typically based on bellows - processed animal hide -, cheese or resin. In the first attempt, the scientists mixed grated hard cheese, milk and slaked lime. Later, they tried a recipe of bladder, brandy and quick lime or use beeswax, resin and quicklime as ingredients.
The most efficient glue was a slightly more complicated mixture of bladder, brandy, garlic juice, ox gall, various resins, vinegar, quicklime and fish glue. The researchers used it to glue a broken cup, which is still stable today, more than five years later.
Patched dishes probably served as decoration
With the counterfeit glue repaired dishes stored the scientists for half a year at different humidity, temperature and different pressure. They also buried a few pieces underground. This was supposed to simulate the time when they camped unnoticed in the basement of the Washington House, which was demolished in 1830.
The researchers then compared the pieces to seven glued original parts from the Washington home. Particular attention was paid to a bowl, which was manufactured between 1765 and 1772 in England. "Usually, guests used such vessels to party and drank some kind of punch," the researchers report.
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Archeology: Adhesive Test in the House of WashingtonThe adhesive on the bowl is to be recognized as a light brown substance, inside the mass was well visible over the joints lubricated. Because the adhesive hardly bears scratches there, the scientists assume that the vessel was no longer used after the repair and served as a decoration. The test also showed that none of the adhesives withstood warm water. To drink punch was the repaired bowl so unsuitable.
"It's possible that George Washington's mother, Mary Ball Washington, mended the pieces because she was emotionally attached to them or as a status symbol," the researchers conclude.
Irritants in use
Finally, examinations under the microscope showed that the adhesives on the seven original pieces closely resembled the counterfeit cheese adhesive. The Washington have therefore patched their dishes therefore mostly with cheese-based glue. The proteins and the fat in the cheese decomposed over time. The mass ultimately contained only the lime components used.
Chemical analyzes in the mass spectrometer confirmed the result, with one exception: on the punch bowl, the scientists found residues of resin in addition to the lime residues. She was apparently patched with a resin glue, the recipe also contained beeswax and heated pine. The fact that different recipes were in use, suggest that in the House of Washington more often dishes were glued, the scientists.
Location of George Washington's childhood home
Since they found no professional drills or metal fixtures in the harness, they assume that Mary Washington repaired them by hand. "Sticking the dishes was time-consuming and dealing with potentially harmful substances," the researchers write.
The burn and slaked lime used in the recipes is an irritant that can damage the eyes and is easily corrosive. It would therefore have been obvious to give the task to experts, but there are no indications. Even in the shelters of the slaves, who kept the family, there was no mended crockery.