This might be surprising to some readers, but Penn State is home to an incredible array of museums (see also the Penn State Museums site) and an inspiring group of curators and museum professionals. We meet almost every month to talk shop, and every time I learn something new about funding sources, outlets for connecting to the community, potential collaborations, professional museology resources, etc. I’m never disappointed.
At our June meeting my colleague John E. Simmons mentioned that June 4th is (unofficially) Old Croone Day. William Croone is apparently the founding father of the modern spirits-preserved natural history specimen, and therefore, really, the modern natural history collection. As stated, in Simmons’ account of the origin (in litt.):
…on this day, in the year 1662, Dr. William Croone appeared before the Royal Society of London and ‘…produced two embryos of puppy-dogs, which he had kept eight days, and were put in spirit in a glass-vial sealed hermetically…’ This is the first recorded mention of modern fluid preservation of a scientific specimen.
A HUGE accomplishment, no doubt. And while I certainly appreciate the significance of this event—the revelation that we can now preserve natural history objects, other than dried insects on pins and pressed plants—I also feel compelled to acknowledge that I’m not bullish on specimens preserved in spirits.
It’s not the specimens’ fault, I know. Some insects are just best preserved in that medium. Immatures, soft-bodied insects, and, surprisingly, adult caddisflies. Even odonate exuviae are typically preserved in ethanol. As a curator, though, these ‘wet collections’ are a time and resource sink.
There is no optimal container, for one. Every single type of vial in the existence of man leaks ethanol vapors. Yes, some are better than others, but eventually (and often rapidly) the collection could end up looking like this:
As my colleague István said: why can’t we just critical-point-dry all these specimens and store them dry?! Anyone have a good answer? Or can we swap out the highly volatile ethanol for a much more stable propylene glycol or even glycerine? Those fluids vaporize at an incredibly slow rate relative to ethanol. And what about the chemicals produced by specimens that rot in ethanol? Brown, stinky ethanol is a regular phenomenon in insect collections, especially in unsorted insect ‘soups’. How toxic are these soups, which often smell strongly phenolic? Specimens are also difficult to access, visualize, process; they require a lot of handling and fluid intervention. And what about changing the preservative – what about the potential to harm the specimen with a new wash of ethanol? I’m feeling the anxiety already, just writing about the management of wet specimens.
Ok, so what are the advantages of wet collections? Well, as mentioned above, there is no reasonable alternative for some taxa/stages. There’s also no museum pest risk—at least if kept filled and with ethanol >70% (I have seen some low percentage ethanol result in moldy specimens; I guess that counts as a museum pest). That’s a huge advantage. The evaporation risk is also less now than it used to be, especially with improved vial/cap technology.
We’re about to wade into our wet collection, actually, as part of our ongoing profiling (PDF) of the Frost. Old Croone Day seems like the perfect day to begin. Perhaps after we pay tribute to William Croone by, as my John Simmons recommends, “sharing a fine single malt whiskey with good friends…”
(p.s. Thanks, John, for sharing this anecdote about William Croone!)
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