Explanation:
1. We could note from the account that Weyman noted the signature and the date found on the bottom of the plate. Also, "f" was observed written on the plate which led Weyman to conclude it indicated authenticity.
2. According to the account, a state is described as occurring when there is a change or addition to the etching. Hence, Weyman was able to know the state of this particular etching since he noticed there is a blank patch on the plate
