Two rolls of zinc foil. Zinc is a blueish white metal. It is a reasonable conductor of electricity and is brittle except at temperatures of between 100 and 150 degrees celcius where it becomes quite malleable.

This foil comes from a 15 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. These rolls of zinc were presumably used by John FW Herschel and/ or his children (it may even have been used by John FW with his children) as the raw materials for experiments.