[Nhcoll-l] Algae in jars - to refill or not to refill

[Gali Beiner]

Hi Simon,

Thanks for a very informative response! The Herbarium staff feel that these
algae may be too fragile (too friable) to transfer to paper sheets. In
addition, yes, salts (crystals) are indeed present in quite a few of the
specimens. Preparations with seawater are pretty likely in this sort of
fieldwork, so I guess we do have to deal with this problem as well.

Gali

On Wed, Jul 29, 2020 at 11:32 AM Simon Moore <couteaufin at btinternet.com>
wrote:

> Hi Gali,
>
> Your problem has given rise to several options.
>
>  If the specimens are still flexible enough to mounts onto herbarium
> sheets…?
> Secondly, if you wish to keep them fluid-preserved then fine but you may
> need to rehydrate the dried-out specimens, I still use 5% Decon-90
> glassware surfactant, gently warmed until they have their natural flex once
> again; it will only take about 30 minutes but holdfasts may take a while
> longer.
> Thirdly, if you replace them into alcohol then any residual chlorophyll
> pigments will be denatured in that fluid.  If they were preserved in
> formalin, that should be a 5% solution only rather than the usual fixative
> strength of 10%.
> Fourthly, if there are salt crystals present in the dried-out specimens,
> then the full-strength formalin (37.65% formaldehyde) will have been
> diluted using sea-water. Bear that in mind as well.
>
> Hoping that this helps.
>
> With all good wishes, Simon.
>
> Simon Moore MIScT, RSci, FLS, ACR
> Conservator of Natural Sciences and Cutlery Historian,
>
>
>
> www.natural-history-conservation.com
>
>
>
>
> > On 29 Jul 2020, at 08:02, Gali Beiner <gali.beiner at mail.huji.ac.il>
> wrote:
> >
> > Dear All,
> >
> > We have a group of jars containing algae, apparently collected in the
> 1970s. Some of the jars still hold a little liquid but most of the solvent
> has gone and quite a few jars are now completely dried out.
> >
> > ... In addition, it isn't absolutely certain what the solvent was -
> possibly formalin. I've been asked whether it would be OK to refill the
> jars with 70% ethanol. Can anyone here give advice relating to algae within
> this context?
> >
> > Thank you,
> > Gali
> >
> > --
> > Gali Beiner (ACR)
> > Conservator, Palaeontology Lab
> > National Natural History Collections
> > The Hebrew University of Jerusalem
> > Berman Building, Edmond J. Safra campus, Givat Ram
> > Jerusalem 91904, Israel
> > Fax. 972-2-6585785
> > gali.beiner at mail.huji.ac.il
> > https://nnhc.huji.ac.il/?lang=en
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>

-- 
Gali Beiner (ACR)
Conservator, Palaeontology Lab
National Natural History Collections
The Hebrew University of Jerusalem
Berman Building, Edmond J. Safra campus, Givat Ram
Jerusalem 91904, Israel
Fax. 972-2-6585785
*gali.beiner at mail.huji.ac.il <gali.beiner at mail.huji.ac.il>*

*https://nnhc.huji.ac.il/?lang=en <https://nnhc.huji.ac.il/?lang=en>*
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