[NHCOLL-L:2506] freezing mounted specimens

[Kathryn Medlock]

We are currently in the process of moving our entire zoology 
collections to new and better storage and of course wish to ensure 
that pest problems are not just transferred. I might say that we have 
few problems at present and have treated things as the need arises - 
usually be freezing.

My problem now how to ensure the best way to de bug items prior to 
the move. The collection contains a lot of recent material but also 
includes valuable 19th century mounts of birds (cased and uncased), 
mammals, trophy heads as well as osteological material across a range 
of species. I have been attempting to find out what the best way to 
go will be.

I am very suspicious of just freezing everything given that it seems 
to be agreed in conservation circles that leather shouldn't be 
frozen. As you would be aware, mounts are made of a wide variety of 
materials - stuffing (straw, wood wool, fibreglass), wire or rode 
metal supports, possibly plaster of paris, glass eyes, wooden base 
that may contain dried vegetation etc etc. What happens to the bills 
of large birds, ivory, teeth, webbed feet etc? Surely these materials 
all react in different ways to the freezing process.

I have been told by some that freezing in OK, by others that teeth 
cannot be frozen. Bromide apparently fades feathers. Carbon dioxide 
is too dangerous and we are not set up for nitrogen.

Does anyone have any suggestions as to the best way to go. I am in 
favour of treating only if suspicious rather than a blanket treatment 
that may result in damage to the material.

Sincerely,

Kathryn Medlock
Curator
Vertebrate Zoology, Tasmanian Museum and Art Gallery


-- 
Kathryn Medlock
Curator, Vertebrate Zoology
Tasmanian Museum and Art Gallery
19 Davey Street
Hobart
Tasmania
Australia     7000

ph: (03) 6211 4126
FAX: (03) 6211 4112
email: kmedlock at tmag.tas.gov.au