Identifying chrome tanned leather

When identifying chrome tanned leather, I have employed a number of
approaches, the choice of which is determined by a number of factors
including sample size and the availability of reagents and
instrumentation.  The BDH spot test handbook includes tests for
Chromium using the sodium salt of Chromotropic acid as well as
1,5-diphenylcarbazide.  If sample size is small (...ranging to
minute) and a microscope is available, there are a number of rather
sensitive tests involving less esoteric reagents that can be carried
out with a good deal of ease and success.  The Handbook of Chemical
Microscopy--Vol II,  by Chamot and Mason (and available through the
McCrone Institute) outlines in some detail the procedures for these
tests using lead acetate, silver nitrate and cesium sulfate as test
reagents.

Scott Nolley
Objects Conservator
Colonial Williamsburg Foundation
757-565-8956

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                  Conservation DistList Instance 12:17
                Distributed: Wednesday, August 12, 1998
                       Message Id: cdl-12-17-003
                                  ***