Dear Taxacomers

We have been investigating recently whether we should revert to our original formula of preserving spirit containing formalin ('Kew mixture'). With COSHH (Control Of Substances Hazardous to Health regulations)
etc. we had opted for the formalin-free concoction containing 58% meths, 5% glycerol and 37% dest. water (all by volume). However, there have been rumours that this mixture leads to the specimens getting too brittle and deteriorating in the liquid (we have not experienced any deterioration yet). Following this rumour I e-mailed all available herbaria and enquired about their preservation techniques. About 20 people replied. None used formalin for plant material (one museum in New Zealand used it for marine arthropods or some such).

Could those of you dealing with spirit preserved botanical material please tell me what your experience is with respect to preserving chemicals. I hesitate to recommend to our herbarium committee that formalin can't be avoided, as this would entail extremely costly alterations to the set up, and make examination of specimens very cumbersome. It appears that Kew are still using formalin mixtures whereas Copenhagen would not consider the introduction of formalin at present.

Apologies to those who have seen this message before.

Yours sincerely

Dr Stephan Helfer, SSO Mycologist

Royal Botanic Garden Edinburgh, Inverleith Row, EDINBURGH EH3 5LR, Scotland UK

email s.helfer at rbge.org.uk phone: +44 (0)131 552 7171 ext 280 or +44 (0)131 459 0446-280 (direct digital VoiceMail line) fax: +44 (0)131 552 0382

Yours sincerely