Posted By:
Tim ParsonIt is an Ambrotype backed by an old Daguerreotype plate that has been blackened on the copper side of the old dag plate(an Ambrotype needs a Black backing) .
This was a common practice, as the Wet Plate Process(Ambrotype/"Tintype") replaced the Daguerreian process,the Photographers would blacken one side of their no longer in demand Dag Plates for backing plates--just to get rid of the now useless plates. I have seen a number of of Ambrotypes backed by old Dags.
It can be very confusing to the novice to tell a Dag from an Ambrotype if the image still retains its seals.(ealy Ambrotypes were sealed with thin strips of paper to the matt and cover glass like most Dags were, a practice that faded out as the Ambrotype process matured).
The image has suffered from poor storage but appears quite stable, although there is no way I am aware of to restore the damaged "Emulsion".
A new backing plate/cover glass/seal and it should be good for another 100+ years.
Tim Parson
Ambrotypist