Displaying soil sample

On 2 August Mark Vine wrote:

>A garden of tremendously historical importance is endeavouring to
>preserve and display a sampling of freshly removed moist soil...
>Within days of removing the soil from its natural environment and
>placing within a modern display case the soil has begun to be
>effected by green mold. Can anyone suggest a means of displaying and
>preserving the moist soil?

I referred this question to my colleagues in our Botany Department
(Botanists, not Conservators) and they came up with the following
responses:

    1.  irradiate it

    2.  a harsh dose of UV would be a start on the sample before
        bottling. After that, how about an algicide being applied to
        the inside of the bottle? There must be more elaborate
        methods too. The exposure to light would appear to be the
        main concern. Refrigeration may help.

    3.  steam sterilise and then moisten with industrial meths (98%)
        instead bug-ridden water?

    4.  difficult to comment upon without knowing more details of
        how the soil is displayed and whether the intention is to
        show organisms moving around within the soil mass/profile.

I wonder whether the 'green' mold is algal growth or a fungus with
green spores. If the intention is for the soil simply to look
'fresh' (i.e. moist looking) then giving it a fine spray of a
preservative might keep it in check--4% formalin (provided in sealed
display unit), or proprietary brand of fungicide. If the problem is
algological then simply keeping it in more poorly lighted conditions
might help.

William Lindsay
Head of the Palaeontology Laboratory
Natural History Museum
Cromwell Road
London, SW7 5BD
+44 171 938 8821

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                  Conservation DistList Instance 10:18
                 Distributed: Tuesday, August 13, 1996
                       Message Id: cdl-10-18-003
                                  ***