The astounding story of the fake butterfly specimen Papilio ecclipsis – would you be fooled?

For April Fool’s Day, our Senior Collections Manager Darren Mann recounts the story of an elegantly fake butterfly – Papilio ecclipsis – asking whether it was a piece of scientific fraudulence or practical joke that went awry.

James Petiver, a 17th-century London apothecary, was renowned for having one of the largest natural history collections in the world. Petiver (1665-1718) published some of the first books on British insects and created common names for some of our butterflies.

Volume 3, Plate II of Jones Icones – the two lower images are of Papilio ecclipsis

On plate 10 of his Gazophylacium naturae et artis — an illustrated catalogue of British insects (1702) he figured a unique butterfly that “exactly resembles our English Brimstone Butterfly were it not for those black Spots, and apparent blue Moons in the lower wings”. It was given to him by his late friend and butterfly collector William Charlton (1642-1702). This butterfly was later named Papilio ecclipsis by the father of taxonomy himself, Carl Linnaeus, in his 1763 work Centuria Insectorum Rariorum, and it became known as the Charlton Brimstone or the blue-eyed brimstone.

Petiver’s collection was purchased by Sir Hans Sloane (1660–1753), who later donated his entire ‘cabinet of curiosity’ to the nation, becoming the foundation for the Natural History Museum, London, originally part of the British Museum. It was here that wine merchant and naturalist William Jones (1745-1818) examined and later figured Petiver’s specimen in his Icones, an unpublished masterpiece of some 1,500 watercolour images of butterflies.

Jones’ Icones, held in the Museum’s archive, is the subject of numerous articles and is still examined by butterfly specialists the world over. Many of the specimens figured by Jones are no longer in existence, being ravished by pests or lost over time, so all that remains of these butterflies are the painted images within.

A drawer of British butterflies from the cabinet of William Jones. The Common Brimstone butterfly is the fourth from the right on the top row

When visiting London, Danish entomologist Johann Christian Fabricius (1745-1808) studied the paintings that Jones made and described over 200 species of butterfly new to science. Fabricius also visited the British Museum where he examined Petiver’s specimen of ecclipsis. In Entomologia systematica (1793) Fabricius revealed the enigmatic ecclipsis to be no more than a painted and “artificially spotted” specimen of the Common Brimstone (Gonepteryx rhamni). So, the dark spots and blue eyes were merely artistic licence, but whose?

Iconotypes, published by Thames & Hudson, will be available from October 2021

Petiver’s specimen, seen by both Jones and Fabricus in the British Museum in the late 18th century, had mysteriously disappeared by the following century. It is said that when Dr. Gray (1748-1806), Keeper of National Curiosities at the Museum, heard of the deception he became so enraged that he “indignantly stamped the specimen to pieces.”

It is still unclear whether this was an example of scientific fraud by Charlton, or if it was intended as a practical joke that went awry.

There remain two specimens of ecclipsis in the collection of the Linnean Society. Although it is uncertain who created these, it is believed that these replicas were made by none other than our very own William Jones, as he was one of the few who had the artistic skills to undertake such work. The forthcoming publication of Iconotypes, showing Jones’ Icones in all its splendour, will hopefully demonstrate how he had both the knowledge and the skill to recreate these fascinating fakes.

Links and References
Salmon, M., Marren, P., Harley, B. (2001) The Aurelian legacy: British butterflies and their collectors. University of California Press.
The Linnean Society https://www.linnean.org/
Vane-Wright, R. I. (2010) William Jones of Chelsea (1745–1818), and the need for a digital online ‘Icones’. Antenna. 34(1), 16–21