Arsenic in bird study skin collection

Genevieve M. LeMoine <glemoine<-a t->bowdoin< . >edu> writes

>The biology department here has a collection of bird study skins and
>mounts some of which date back to the nineteenth century.  All of
>them have been treated with arsenic (a now elderly former student
>remembers his summer job sprinkling arsenic on them...) and most
>likely a variety of other chemicals too. Does anyone have any
>suggestions for cleaning these specimens?

I am a zoology technician and a few months ago I had the same
problem and wrote to the list. Below there are two kind message I
received. Following there is my personal experience.

Fiona Graham, Museum Planning Advisor, Canadian Conservation
Institute wrote (quoted with permission):

    I worked at the Saskatchewan Museum of Natural History (now the
    Royal Saskatchewan Museum) when there was a fire which caused
    soot deposition on all collections, including thousands of
    mounted birds. Sarah Spafford and I searched the literature for
    information on cleaning feathers and discovered that there was
    not a lot that was useful to us.

    We did our own tests and developed a system for cleaning the
    birds.  I think that many of our materials and techniques would
    work on dust as well as on soot. We published two papers in
    Volume 1 of the Preprints of the 1993 ICOM-CC Washington
    Conference.  I suggest that you look at these papers.  If you
    cannot find them, or if you need more details on the techniques,
    please contact me.

    The degree of success of the mechanical cleaning techniques will
    depend to a large degree on how strongly the dust is attached to
    the feathers.  Older dust will be more strongly attached, and
    the preparation of the specimens sometimes leave them with an
    oily surface which traps dust and binds it into a dirty crust.
    You may indeed need to use solvents to clean off the dust, in
    this case.

    We used trichloroethylene but not dimethylketone or lac thinner.
    The problem with any solvent cleaning is the ability of the
    solvent to strip natural oils from the feathers.  This can
    change the chemistry and appearance of the feathers.  There is
    thus a fine line between removing the dust which is harmful
    (often acidic) and disfiguring, and irreparably damaging the
    specimen for research and sometimes aesthetic purposes.

    I strongly recommend that you test various techniques and
    solvent combinations on one specimen, using a microscope to
    check the results. I would be very interested in knowing the
    results of your work in this area...

    **** Moderator's comments: For the other response, check the
    Archives in CoOL:
        Sally Shelton "Cleaning mounted birds", 19 Nov 96
        (the Author index will probably be easiest)

And here is my experience:

In our Museum *all* Birds (about 5000) and Mammals (more than 8000)
specimens were prepared using "arsenical soap" a solution made with
arsenic, soap, K2CO3 (potassium carbonate) and something else (I do
not know the English for other components) painted on the inner side
of the skin. I have to deal almost daily with these animals and I am
careful but not scared about arsenic.

Last march I cleaned 50 specimens of birds for a temporary
exhibition and I used for protection: gloves (in latex or vinyl) and
a mask to avoid breathing dust.

First of all when cleaning birds you must check the specimen
carefully to see if it is damaged, broken, attacked by Dermestid
beetles, well stuffed and if feathers come off easily due to a poor
mounting. You have then to decide the "degree of cleaning" and the
treatment your specimen will be able to stand.

I cleaned coloured specimen with a gentle brush (make up brush) and
by beating them lightly with a flexible wooden stick. Both this
technique and the use of solvents were almost useless for white
animals that remained gray with all the dust strongly attached to
them (a lot of specimen in our collection are about 100 years old).

Following the advice of an Italian colleague I decided to wash the
birds in worst condition. I used a soap-free shampoo and dried the
specimens, first covering them with potatoes starch, then with an
hair dresser (with a diffuser) and finally with a drier at 50 deg. C
for 24 hours.

See a wet Snowy owl covered with potatoes starch scares a bit but
final result is very good: when you remove all the dry starch
feathers are fluffy and white again. This technique seems to me very
simple and a bit "primitive": I wonder if and how it could damage
the specimen, anyway I think shampoo is less aggressive than a
solvent and a careful drying should keep away fungi.

On a mounted group of five completely white birds I tested another
technique: cleaning with a solvent and drying with potatoes starch
and hair dresser; also this method gave good results and it is very
quick. The starch makes the difference: absorb both solvent and old
dust.

Please contact me if you need more details.
Best wishes for your work.

Roberta Salmaso
Museo Civico di Storia Naturale
Lungadige Porta Vittoria 9
I - 37129 Verona, Italy
+39 45 8079417
Fax: +39 45 8035639

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                  Conservation DistList Instance 11:47
                Distributed: Tuesday, November 25, 1997
                       Message Id: cdl-11-47-002
                                  ***