It was awarded – in a very informal vote – the title of the best science book ever written, but what makes it a science book at all? Levi was a working chemist, but the title is a metaphor and even this figure of speech is sometimes a little strained to comply with the book's scheme.

Some of it is personal memoir, and chapter headings such as Argon, and Iron, seem barely justified by the reflections that follow. Some stories are overtly fiction, which is surely the antithesis of science writing. One or two are attempts to address the process of industrial science from, so to speak, the floor: Sulphur is a compelling account of a wartime factory hand's hours on the night shift, but what is he making, and why does he need such temperatures, such vacuum readings?

Some of it is about etymology, about the nature of words and their casual links with the elements around us. And some of it is urgent, cruel, personal history: the story of a young man born into a Jewish family, educated in Fascist Italy, all but destroyed in Auschwitz. The chemistry is important, but often incidental. And finally, it is not Levi's greatest work. For that, go to If This Is A Man, and The Truce.