Mounted microscopial specimen in a box marked AST1029.25.

The microscope slide comes from a fifteen drawer cabinet found in the Herschel family home in the 1950s. Collectively the contents of this and a similar cabinet seems to suggest that they were used by successive generations of the family to store specimens, material and apparatus for carrying out experiments.
Handwritten inscription reads 'Xtallizn on platinum in a carbon kiln (? C or Si) - J. Swan Dec 1880'. Again, Xtallizn is short for Crystallization.

J. Swan almost certainly refers to Joseph Swan (1828-1914) who was based for a large part of his life in and around Newcastle and was at the time these slides were produced actively involved with the Newcastle Chemical Society. Joseph Swan is an important name in the development of electric lighting developing a carbon filament incandescent lamp in 1860. It seems plausible to suggest that these slides were given to Alexander Stewart Herschel, also based in Newcastle at the time, by Joseph Swan and were related to explaining his work on electric lighting.