Possibly some of the earliest unexposed photographic plates in existence? This sealed package has just arrived via the Ebay time machine. Dating them by the logo, these could have been made as early as 1885, when Alfred Harman was still in his cottage in Ilford, hand pouring his plates from a silver teapot.
If it’s possible to make images on them it will be something along the lines of tapping a ouija board & getting a response. Early slow blue sensitive plates can often still function – but 130 years on?
Or like the Turin Shroud should are they better left intact as an artefact to drift on through time? Decisions…