I read this book over twenty years ago and loved it. The atmosphere, the idea of a wild ass's skin representing Valentin's health, and the gloominess differ from other widely-known Balzac's works, but this one is my favorite. Balzac's famous character, Rastignac, also plays a part in this novel. And, of course, it made me wonder how I would try to trick the shagreen, would I use it for other's well-being or only mine, how would I do this, how would I handle that... and books that make you get to know yourself better are always high on my list.