Posted: 18 Jan 2019 06:32 PM PST
A classroom periodic table of the elements found at the University of St Andrews in Scotland is the oldest known in the world. It was discovered in 2014 by Dr. Alan Aitken in the storage area of the School of Chemistry. He was cleaning out the clutter of chemicals and equipment that had built up since 1968 when he came across a roll of old teaching charts. Among them was a chart of the period table that was so old the paper flaked to the touch.
Siberian chemist Dmitri Mendeleev first arranged the known elements by their atomic mass after seeing them all fall into place in a dream. He was writing a textbook for the chemistry course he was teaching, and realized elements with similar properties also had similar atomic weights, or weights that increased at a regular rate. He presented his chart and the periodicity of the elements to the Russian Chemical Society in 1869. Other scientists had independently realized that the elements could be organized in periods and created tables in the 1860s, but Mendeleev’s was the simplest and made predictions that would be confirmed accurate with the discovery of more elements.
In 1871, he released a second table correcting a few errors in the first. The chart found at St. Andrews is similar to the 1871 version, but printed some years later.
The years spent rolled up in a chem lab closet have not been kind to this possibly unique artifact of science history. The paper was mounted on a heavy linen backing which exacerbated its fragile condition and an immediate intervention was necessary to conserve it. Experts from the University’s Special Collections secured a grant to treat the chart. Working with private conservator Richard Hawkes, Special Collections conservators cleaned it, separated it from the linen backing, washed it in a neutral solution to remove discoloration, de-acified the paper in an alkaline bath, and repaired areas of loss with Japanese kozo (mulberry bush) paper and wheat starch paste.
The periodic table is now stable and being maintained in climate-controlled conditions in Special Collections’ stores. It is too delicate a piece to go on public display. Thankfully the grant money also made possible the creation of a full-size replica. The facsimile is on display in the School of Chemistry.
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