Naturally hot nature. Its signs are: large width of the veins, their visibility and warmth of the blood and body, unless the heart opposes such a conclusion; the fact is that the warmth of the heart greatly overcomes the coldness of the liver. Other signs: abundant generation of yellow bile in the liver at the end of adolescence and black bile - later than this age, an abundance of hair on the false ribs, a strong urge to eat and drink. Natural cold nature. Its signs are opposite to the above signs. The coldness of the heart suppresses the warmth of the liver less than its heat suppresses its coldness. Since people with a similar nature have thin, watery blood, and their strength is weak, they often experience fevers. Natural dry nature. Its signs are: a small amount and density of blood, hardness of the veins, dryness of the whole body, density and curly hair. The heart, with its moisture, does not correct the dryness of the liver to any significant extent, and does not even suppress it at all, but the dryness of the liver greatly suppresses the moisture of the heart, and the warmth of the heart suppresses the moisture of the liver with great force. Natural wet nature.
Its signs are opposite to the above signs. The dryness of the heart sometimes, to a very small extent, corrects the moisture of the liver, but its moisture greatly suppresses the dryness of the heart. Natural, hot, dry nature. Its signs are: thick blood, an abundance of black hair near the false ribs, a large width of the veins, along with their fullness and density, abundant generation of yellow bile and black bile at the end of youth and warmth and density of the body, unless the heart refutes such a conclusion. Natural hot wet nature. Such a nature is indicated by a large abundance of blood, the good quality of its composition, a large width of the veins with their softness, a red complexion without yellowness, thick hair on the false ribs, but less abundant than with a dry hot nature, and not so thick and curly, as well as softness of the body due to its warmth and moisture. If warmth prevails, then the body remains healthy, but if the humidity is stronger, then putrefactive diseases rush to it. Natural cold dry nature. It is indicated by a small amount of blood, low warmth of the blood and body, narrowness, invisibility and density of blood vessels, scant hair on the abdominal walls and dryness of the whole body.