[NHCOLL-L:1278] Fwd: formalin? Gasp!

[Amy Estep]

Thank you for all of the great responses and suggestions.  I will try the
hydrometer method described on the list by Steve Rogers since I have one on
hand.  Also, the message below was sent to me by Simon Moore in which he
describes a specific gravity meter that he developed using map pins and a
bottle dropper (see Carter and Walker's 1999 book, Care and Conservation of
Natural History Collections).  I tried this method recently with no success but
will try again with different map pins...the pin heads I used on the first
attempt sank in both 10% formalin and 70% ethanol.

Cheers and many thanks,
Amy



"Moore, Simon" wrote:

> Dear Amy Estep,
>
> Your enquiry was forwarded to me as I specialise in fluid preservation
> problems.
>
> I have tried leuco-basic fuchin impregnated papers but if they test
> positive, the pink dye can colour the fluid and no matter how careful you
> are using forceps and gloves, the dye gets on hands at some point and looks
> most unattractive!  Also, such papers need to be stored in the dark and have
> a limited shelf life.
>
> So I devised a specific gravity test using map pin heads.  Details are in
> Care and Conservation of Natural History Collections, 1999, Eds. Carter DJ &
> Walker A, Butterworth Heinemann: 100-101,  Basically it just involves
> pulling the heads off two differently coloured map pins (or how many you
> wish to use to distinguish fluid specific gravities) and then push back into
> the head enough of the pin so that it will float in fomalin and sink in
> alcohol - other pins can also be adjusted to distinguish between lower grade
> alcohols (following evaporation?), formalin and full strength alcohol.  If
> you can get hold of a dropper bottle with a reservoir (as shown in the book)
> it looks neater.
>
> Hope this will help and keep your Health & Safety Officer happier.
>
> With all good wishes, Simon Moore.

--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Amy D. Estep
Curatorial Specialist in Herpetology
Sam Noble Oklahoma  Museum of Natural History
University of Oklahoma
2401 Chautauqua Avenue
Norman, OK  73072
v:  405-325-1516
f:  405-325-7771
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~