Dufour, in his Trait de l'entendement, drew up a summary list of the recognised causes of his day: The obvious causes of melancholy are all those elements that immobilise, wear out or trouble these spirits; great, sudden frights, violent movements of the soul resulting from transports of joy or intense affection, lengthy, deep meditation on a particular object, intense love, lack of sleep, and all excessive exercise of the worried mind, particularly at night; solitude, fear, hysterical affection, anything that impedes growth, healing, the circulation, the various secretions and excretions of blood, particularly in the spleen, the pancreas, the omentum, the stomach, the mesentery, the intestines, the breasts, the liver, the uterus, the haemorrhoidal vessels; consequently the hypochondriac illness, acute diseases imperfectly cured, principally frenzy and causus, all medications or excretions, when over abundant or interrupted, and consequently sweat, milk, menstrual fluid, lochia, ptyalism and scabies.