Identifying chrome tanned leather

This is posted on behalf of David Dorning.

    A very simple test is to take a small piece of the leather and
    burn it in an intense bunsen flame. Keep burning until it is
    carbonised then let it cool. Chromium-containing leather will
    show a slightly green coloured ash. You can compare it with some
    known vegetable tanned leather which should have a grey ash, or
    alum-tawed skin--any aluminium-containing skin will have a
    noticeably white ash.

    David Dorning
    Paper Conservator, Science Tutor
    Conservation of Rare Books and Manuscripts
    West Dean College

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                  Conservation DistList Instance 12:15
                 Distributed: Wednesday, August 5, 1998
                       Message Id: cdl-12-15-007
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