This post is part of an ongoing series featuring items recently cataloged from the Julio Mario Santo Domingo Collection.
This collection has been especially rich with volumes by Charles Baudelaire who though most famous as a French poet was also an art critic, essay writer, and translator of Edgar Allen Poe. La Fleurs du Mal, The Flowers of Evil, is one of his most recognized works of prose-poetry and is about the changing nature of beauty in the newly modern and industrialized city of Paris in the 19th-century. This volume of La Fleurs du Mal was published in 1900 and has an extraordinary binding. My colleague at Houghton, Ryan Wheeler, did some investigation about the binding while he was cataloging it and turned up some fascinating information. Apparently the binding process is known as vellucent, developed by the binder Cedric Chivers of Bath, England. An artist would paint the original illustration onto the boards, and then a thin, translucent layer of vellum was laid over that, so that everything but the gilt is under the vellum’s surface, including the mother-of-pearl. 
On the cover you can see gilt around the creature’s head and on the spine, and on the back cover both the woman’s hair-bow and the sliver of a moon are mother-of-pearl. The illustration on the cover continues around to the spine so that we can see the arm reaching toward the flowers and the depiction of his wing is carried over onto the back cover. We are fairly certain that H.G. Fell is the illustrator and apparently he collaborated with Chivers on many other volumes. And if the binding isn’t impressive enough the volume also has a surprise fore-edge painting. A fore-edge painting is completely invisible when the text block is closed, but if you fan the pages in a certain direction, an image appears, in this case a skeleton.
You can watch a video of the skeleton appearing on this volume below:
To discover the secret skeleton for yourself you can find this volume in Houghton Library’s collection. Les fleurs du mal par Charles Baudelaire ; précédées d’une notice par Théophile Gautier. Paris : Calmann-Levy, 1900. FC8.B3247.900f.
Thanks to Alison Harris, Santo Domingo Project Manager, and Ryan Wheeler, Rare Book Cataloger, for contributing this post.