Avicenna on the Four Humours: Sanguineous/Serous/Bilious/Atrabilious/Blood/Phlegm/Yellow Bile/Black Bile

After describing the nature of the humours and their types, Avicenna in his Law of Natural Healing (Canon of Medicine), Lecture 4, goes into detail about each of the four humours and how they are produced. It also contains O. Cameron Gruner's extensive endnotes.