This set of lecture cards from 1857-58,
University of the City of New York, Medical Department, was
obtained with all of the 18 card back-sides having been well glued to an 1858 ledger
paper and on top of the ledger paper was glued a period news-paper.
Who knows why, but that is the way they were found. The
problem was how to remove the two layers of paper from the back of
the lecture cards without damaging the lecture card material. Fortunately the glue was water soluble.
The following procedures were first tested on
one of
the least valuable of the cards and technique refined as results were
obtained:
First, the news-paper was removed by dobbing a
wet (not dripping wet, but wrung out) paper towel on the news-paper until it became translucent,
which took about a minute to accomplish.
At that point, the paper was easily removed, revealing the ledger
page below with ink hand-writing. The ledger paper did not react
well to
soaking with a wet towel, so a hand-held clothing steamer with
purified water was used to wet and cause the release of the ledger
paper from the back of the lecture card. The steamer was
purchased at Target for $33 to keep things very simple and the
instrument worked to perfection.
Once the ledger paper was steamed for
approximately 10 - 20 seconds, the edges could be tested to see if
they would release. If they could be lifted, then they were
pulled up until resistance was felt and further steaming was
applied to the top of the ledger paper. Usually once the paper
started lifting off, it continued in one piece or tore into strips.
The remaining thin strips could be again soaked with the wet paper towel and
removed with a thumbnail as they were soften by the water absorbing
along the edges of the ledger paper.
Any remaining glue was wiped off the back of
the card with a damp paper towel, and the card
was dried quickly with a dry paper towel on a flat surface. The card was then
quickly placed
with the backside down on a non-stick surface (Corion kitchen counter top)
and a heavy telephone book was placed on top of the card with the
face side turned up. After drying for 10 - 20
minutes, if the card was sticking to the counter top, then a large
sharp knife was passed under the card and used to gently break the
bond and lift the card for further drying with the phone book on
top. Phone books were left on the cards for
three hours or until the card appeared to have flattened and dried
completely. This part varied for any given card due to degree
of dampness from the procedure, which was minor from the steam.
(Caution: the steam will cause the cards to curl if applied too
long. However the flatten right back out when left under the
pressure of the phone book to dry.)
The whole set of 18 cards survived this
procedure in excellent shape and the ink signatures on the backs of
the cards were totally preserved and did not run.
