Rare Blue Treasure found in Manchester Museum Herbarium!

Posted on January 22, 2020

Guest post from James Dowling, PhD Student (Biochemistry)

There I was, sorting through the endless piles of old papers and journals that made up the stockroom of the Herbarium.

I was tasked with searching for ‘interesting’ things, which is a very enigmatic term; it suggested, first of all, that there was something interesting to be found, which after hours of unloading boxes I was starting to think was a bit of a pipedream. But more so, it hinted that there was a very real possibility of finding treasure. A glimmering light in the proverbial rubble.

Treasure, from the pirate stories of olde, has always been gold and silver. Never has it been blue. This made it all the more surprising when, beneath the dusty pages of so-and-so journal from 1905 number 27, I spotted something rather peculiar…….

The jacket was remarkably decorated, and clearly designed with great tact and care, bearing the date 1880 prominently near the bottom. I opened the little book up, and inside was something truly remarkable….

Bleached into the blue pages were a series of ghostly white silhouettes. When you gaze upon them, they appear to gaze right back at you – eternal imprints in time of what Dante might have believed to be a close-up of an angel’s wing.

Returning to the front cover, I could see that, sadly, they weren’t evidence of the divine lurking in Herbarium, but instead they were images of ferns from New Zealand.

I brought the little oddity to Rachel, the curator of Botany at the Museum, and she was just as taken by it as I was. Whereas I would have left it on the side as something ‘cool’ to look at every once in a while, she was much more astute in getting to the bottom of this mystery – what exactly is this thing?

That’s when we came across this paper, which described this book in great detail, along with matching photographs.

As it turns out, in 1880, a botanist called Herbert Dobbie produced something known as ‘The Blue Books’. In this category are also included books from a couple of years later by another botanist, Eric Craig.

Apparently, in very vague fashion, Dobbie said 40 years after publication that he made them using “the blue-print system which has just reached New Zealand”. In brief, this involves exposing sensitised mounting paper to sunlight an then washing with potassium bichromate, leaving the characteristic white-on-blue visual effect.

The question still remained, however – why make these little books? Well, that part isn’t so romantic – he stated that he literally wanted to make some money. Out of all the ways to make some cash, this is one of the most creative I’ve come across. To produce pretty books of hauntingly beautiful plants.

The amount of labour that went into making one ‘Blue Book’ was enormous, and combined with no evidence to the contrary, there probably weren’t many of these things made. In fact, only 14 copies are known to have survived, 11 of which are in New Zealand libraries.

Maybe that means there are 15 known to exist now?

Currently, the fate of the little blue treasure has yet to be decided. It will either continue to reside in the Herbarium, though from now on much more appreciated than before, or it will be passed onto another collection.

It was such a treat to unearth this thing, some 140 years after it’s creation, in near-perfect condition. It begs the question as to what else lies lurking in the back of the Herbarium. We’ll see soon enough, but for now, it’s time to close the book on this one.