Jacchinus, chapter 15 on book 9 of Rhazes, assigns the same cause. He gives the example of a patient who married a young wife in a hot summer and dried himself out so much with bedroom work that he passed in a short time from melancholy into madness; Jacchinus cured him with moistening remedies. I find a similar example in Laelius a Fonte Eugubinus, consultation 129, of a Venetian gentleman who, for the same reason, first became melancholy and then mad. Read the full story there.

Stopping any other discharge will cause it, just as with those already named, whether from a boil, ulcer, drainage sore or the like. Hercules de Saxonia, book 1, chapter 16, and Bernard of Gordon confirm this from experience. They saw someone wounded in the head who, while the sore remained open, “had lucid intervals”—was well; but when it was closed, “melancholy returned”: his melancholy fit seized him again.

Artificial evacuations have much the same effect when used at unsuitable times or to excess: sweat baths, bathing, bloodletting and purging. Baths, whether natural or artificial, dry the body too much if used excessively, and do harm when extremely hot or cold: the one dries too much, the other cools too much. Montanus, consultation 137, says they overheat the liver. Johannes Struthius, Stigmat. artis, book 4, chapter 9, argues that staying longer than usual in the bath, bathing too often or at unsuitable times putrefies the body’s humours.

Magninus, book 3, chapter 5, writes to the same effect. Guaineri, treatise 15, chapter 21, rejects all hot baths for burnt melancholy. “I saw,” he says, “a man suffering from gout who came to the baths to escape his illness and was immediately cured of it, but acquired something worse: madness.” This judgement, however, varies with the humour, according to whether it is hot or cold. Baths may benefit one melancholy person and harm another; what cures the condition in one may cause it in someone else.

Neglecting bloodletting can often do much harm to the body when there is an obvious excess of corrupt humours and melancholy blood. When the humours heat and boil, if bloodletting is not used in time, those so inflamed are in great danger of going mad. But when used without judgement, at an unsuitable time or to excess, it does just as much harm by cooling the body and dulling and consuming the spirits.

As Johannes Curio rightly objects in his tenth chapter, such bloodletting does more harm than good: the humours rage much more than before, and it is so far from preventing melancholy that it increases it and weakens the sight. Prosper Calenus makes the same observation about all bloodletting unless a very good diet is followed afterwards. Indeed, as Leonartus Jacchinus says from his own experience, many people’s blood is much blacker after bloodletting than it was at first.

For this reason, presumably, Salustius Salvinianus, book 2, chapter 1, will not allow or hear of any bloodletting in this disease unless it plainly proceeds from blood. He was, as appears from his own words there, in charge of a hospital for the insane, and found by long experience that this kind of evacuation, whether from the head, arm or any other part, did more harm than good.

Felix Plater takes the opposite view: “Though some look askance at, reject and entirely oppose all bloodletting for melancholy, I have found through long experience that countless people have been saved by it after being bled twenty, indeed sixty times, and have lived happily afterwards.” In the old days, in Galen’s time, it was usual to take six pounds of blood from such people at once, when now we scarcely dare take ounces. “But let the physicians look to that”: great books have been written on the subject.

When corrupt humours abound, omitting purging upwards and downwards may be harmful. Yet, as in the previous case, purging that is excessive, too frequent or too violent weakens their strength, says Fuchs, book 2, section 2, chapter 17. Even if they are strong and can bear the medicine, it still brings them into a bad bodily condition: they make their bodies no better than apothecaries’ shops, and this disease and similar infirmities must inevitably follow.