The book is a catalogue of passions as well as a compendium of quotes and stories – not so much a medical treatise, even though there are, and must be pages on anatomy and physiology. For black bile was a medical concept, one of the four bodily humours or fluids that coursed through the organism and determined its constitution, and along with it, our appearance and character, our strengths and weaknesses, our tastes, propensities and illnesses. To talk about melancholy was to engage in and endorse humoural theory. In its terms, black bile was a “cooked” version of yellow bile, or choler. The other two humours were phlegm, and blood. Mooted by the Hippocratics in 5th-century BC Greece on the basis of the view of the pre-Socratic philosopher Empedocles that all matter was composed of the four elements, the humoural system that developed in the West (China and India each have their own humoural systems as well) had been systematized in the 2nd century by the Roman physician Galen, who associated humours with temperaments. Black bile might be noble, in some of its manifestations. But it was at first a crass outcome of digestive processes. Burton explained: “The gall, placed in the concave of the liver, extracts choler to it: the spleen, melancholy; which is situate on the left side, over against the liver, a spongy matter, that draws this black choler to it by a secret virtue, and feeds upon it, conveying the rest to the bottom of the stomach, to stir up appetite, or else to the guts as excrement.” (I, 12,4)