Most often it comes from raw mucus, caused by indigestion, scattered and copious, which overcomes the natural force; in most cases, its harmfulness is facilitated by a weak stomach. When such mucus begins to move and begins to rot, it overpowers the natural force even more and, as it were, plunges it into bewilderment: if the force is left face to face with matter, then the force will not be enough, and if they engage in the careful removal of matter, the matter will not obey or will come into a movement that will stifle power. If they try to remove the matter abruptly, by loosening or bleeding, then the natural strength will not withstand this, and how can it withstand it when even with immovable matter the patient faints. But despite all this, the need of the sick for emptying is great and their need for nutrition is also great, for in their juices there are no substances that nourish the body, so the body is deprived of nutrition. If a sick person is forced to eat, then the rising matter increases, and if he is not fed, then his strength decreases.
At the beginning of such a fever, sometimes something cold pours into the heart and fainting occurs, and the pulse becomes small, slow and rare. After this, nature tries to warm the matter and make it rarefied, and decay, which moves some of its particles, contributes to this. Then the heart gets rid of the harm of coldness, but is exposed to the harm of warmth, and the pulse becomes fast, especially when compressed, faster than in other fevers, although the smallness, slowness and infrequency of the pulse still predominate. An attack of such a fever is similar to an attack of mucous membranes, and it does not leave the patient. With this fever, there is great swelling of the face and puffiness of the body. The complexion of patients does not remain in one state, but, on the contrary, sometimes becomes watery, sometimes leaden, sometimes it turns yellow, and sometimes black. Their lips sometimes look like those of a person who has eaten mulberries, and as for their eyes, they are dull and green; at the height of the disease, they bulge greatly and become like those of a strangled person. The patient's hypochondrium is greatly swollen, like all his insides, and he sometimes vomits sour, and if he has a tumor somewhere in his insides, then there is no hope of healing. Such fever sometimes also occurs from the predominance of thick yellow bile; at the same time, a burning sensation is felt in the insides, and the patient vomits bile. Its attacks are most often similar to attacks of mucous fever.