Signs drawn from the correspondence and inconsistency of external influences on the brain, the speed and slowness of the brain’s response to them.

As for the signs drawn from the correspondence and inadequacy of external influences, and the speed or slowness of the response to them, it should be said that appropriate and inappropriate influences are taken into account either when a person considers himself healthy and does not complain about anything, or when the body loses health and his nature deviates from the natural state. When a person considers himself healthy, everything that is similar to his nature corresponds to him, and from this his nature is recognized, and in such a state, what is opposite to a person by nature is not corresponding. As for the case when a person loses his health and his nature changes, here the judgment will be the opposite.

In previous general discussions we have already said that health is not determined in every body by the same nature; The health of one person may be due to a certain nature, but the same nature brings illness to another person. However, it is also necessary to take into account what does not correspond to a given person in any one respect, comparing this with what does not correspond to him in another respect, in order to presumably determine the degree of balance of his nature. After all, both extremes do not correspond to health and necessarily cause suffering; For any healthy person, there is only such a deviation from balance that is not too excessive. The brain suffering from a hot disorder of nature benefits from cold winds, cold waters and food, as well as odorous substances with a cold quality, whether they are fragrant, such as perfumes with camphor, sandalwood, water lily, and the like, or fetid, such as, let's say dirt and duckweed. In this case, rest and peace are also helpful. A brain with a cold nature disorder benefits from the opposite of this. He benefits from hot air, fragrant and foul-smelling substances with a hot quality, which also dissolve juices and warm, physical exercise and movement. A brain with a dry nature disorder suffers from evacuation and purification, while a brain with a wet nature disorder benefits from evacuation and purification.

As for judgments based on a quick response to influences, when the brain, for example, quickly warms up or cools down quickly, then if it warms up faster, this indicates a hot nature, with the caveat given in the General Book. The same is true if the brain cools quickly or dries out quickly; this occurs due to the low humidity of the brain or the fervor of his nature. However, the difference here is that in the first case there are also other signs of brain dryness, such as insomnia and the like, which we will mention in the paragraph on the signs of brain nature. In the second case, dryness sometimes occurs with sudden movements or from extreme heat or similar causes, but then, at other times, there are no signs of dryness. And with dryness from a hot nature, there are other signs of the warmth of nature. The rapid moistening of the brain is sometimes due to the warmth of its substance, sometimes to the coldness of its substance, sometimes to the moisture of its original nature, and sometimes to the dryness of its original nature. If it is due to warmth, then there are signs of warmth; in addition, such hydration does not occur constantly, but occurs after excessive warmth arises in the brain, which attracts fluids to it and fills it. Then, if the hot nature remains predominant, it entails dryness with chilliness, and if moisture predominates, the brain again becomes cold and damp. When heat and humidity are equal, then in most cases rotting, putrefactive diseases and tumors occur. The fact is that such moisture is not innate, with which innate heat disposes naturally; on the contrary, it disposes of this moisture in an unusual way, that is, it causes rotting.

If rapid hydration of the brain is caused by coldness of nature, then moisture does not appear immediately, but over the course of days; then comes hydration, which occurs quickly, and signs of the cold nature of the brain are evident. If this phenomenon occurs from the moisture of the brain itself, then the speed of hydration is determined by one of two reasons. It happens that moisture produces cold, and cold spoils the power that digests and changes food, which reaches the brain, and moisture arises in the brain. When such cold occurs immediately, moisture follows quickly and suddenly. If at the same time blockages are formed in the passages, then the excess is retained, and the moistening becomes constant and incessant and is not one of the phenomena that occurs rarely, from time to time. Or, rapid hydration of the brain depends on dryness and is caused by increased moisture absorption, which begins as soon as dryness occurs. It is accompanied by signs of previous dryness and resembles moisturizing resulting from warmth; the difference is only in the signs of warmth and signs of dryness. These are the indications drawn from the speed of response to influence. The speed of response, especially to hydration, should not be considered as something dependent on the weakness of natural forces, for the weakness of natural forces itself depends on one of these reasons. Compliance or non-compliance is considered not only from a qualitative point of view, but is sometimes determined by the position and movement of the patient. Thus, we see that a person suffering from a disease called baida prefers lying on his back to any other position.