Isagoge

Concerning the number of ages.

There are four ages: adolescence, youth, old age, and decrepitude. Adolescence is characterized by heat and moisture, in which the body grows and increases up to the twenty-fifth or thirtieth year. Youth follows this, which is hot and dry, where the body maintains perfection without the diminution of strength, ending around the thirty-fifth or fortieth year. Old age succeeds this, cold and dry, in which the body begins to diminish and decrease, though it does not yet fail, extending to the fifty-fifth or sixtieth year. To this succeeds decrepitude, through the collection of phlegmatic humor which is cold and moist, in which the virtue fails, and it measures its years until the end of life.

Concerning the color of the skin and its division.

The color of the skin happens in two ways: either the interior parts provide for it, or exterior factors draw it out. From the interior, it happens in two ways: either from abundance or from the equality of humors. From equality is that which is composed of whiteness and redness. From inequality proceed black, citrine, red, glaucus bluish-gray, and white color. The red, black, and citrine colors of the eyes signify heat dominating the body; citrine alone signifies red bile, black alone signifies black bile, red alone signifies an abundance of blood. White and glaucus signify coldness dominating the body; glaucus signifies it has its cause from melancholy, white from phlegm. Colors arrive from exterior things, just as frost makes colors on the Scots, or heat on the Ethiopians, and many other things. There are also other special or spiritual colors, either from fear, anger, sadness, or other movements of the mind.

Concerning the colors of hair.

There are four colors of hair: black, red, glaucus, and gray. Black is made from the abundance of choleric humor or the burning of much blood; red is from the excess of heat not burned, whence red hair is always made; glaucus is from the abundance of melancholy; gray is made from the excessive defect of natural heat and the effect of putrid phlegm, which happens mostly in the elderly.

Concerning the tunics of the eyes.

The tunics of the eyes are seven, and the humors are three. The first tunic is called the retina, the second the secundina, the third the sclerotic, the fourth the arachnoid, the fifth the uvea, the sixth the cornea, the seventh the conjunctiva. The first humor is vitreous, the second is crystalline, the third is albugineous egg-white-like, which is before the uvea tunic.

Concerning the colors of the eyes.

There are four colors of the eyes: black, whitish, varied, and glaucus. Blackness is made from the defect of visible spirit, or its disturbance, or from the scarcity of the crystalline humor, or because the crystalline humor recedes further inward, or from the abundance of the humor that is like the white of an egg, or from its disturbance, or from the abundance of the quality of the uvea humor. Whiteness is made from the seven contrary things mentioned above, i.e., from the abundance of visible spirit or its clarity, or from the size of the crystalline humor and its eminence, or from the smallness of the albugineous humor and its clarity, and the defect of the quality of the uvea humor. Varied and glaucus colors happen if they agree with the things that cause blackness and whiteness. A clearer color signifies the visible spirit is more abundant and clearer in its variety. A glaucus color signifies the visible spirit is less abundant and tends toward black in its glaucosity.

Concerning the modes of body qualities.

There are five modes of body quality: excessive thickness and attenuated emaciation, synthesis a state of being composed/solid, squalor, and equality. There are two species of thickness: the abundance of flesh and fatness. Abundance of flesh is made from the abundance of heat and moisture. Fatness is made from intense cold and moisture. The diminution of fat or attenuated emaciation is made from intense heat and dryness. Synthesis is made from intense cold and dryness. Solidity is made from coldness and intense moisture, or a combination of both. Equality is made from the equality of humors. These are the forms of the body.

Concerning the difference between male and female.

Male differs from female in that the former is hotter and drier, the latter contrarily, colder and moister.

Here begins the treatise on non-natural things, and first concerning the change of air.

The change of air happens in five ways: it happens from the seasons of the year, from the rising and setting of the stars, from winds, and from lands and their fumes.

Concerning the seasons of the year.

The seasons of the year are four: spring is equal, hot and moist; summer is hot and dry; autumn is cold and dry; and winter is cold and moist. The nature of the air is changed by the stars, for when the sun approaches the stars or they approach it, the air becomes hotter. And when these are separated from each other, the coldness of the air decreases or increases.

Concerning the number of winds and their qualities.

There are four winds: subsolanus east wind, favonius west wind, septentrio north wind, and auster south wind. Each has three qualities: cold and dry, hot and moist; the other two are of equal virtue. Among them, i.e., in the east wind, heat and dryness are attributed; to the other, i.e., the west wind, coldness and moisture are attributed; the south wind is a little hotter and moister, the north wind is colder and drier.

Concerning the modes of lands and their qualities.

The modes of lands are four: altitude, depth, proximity to mountains and sea, and the equality of the lands or places by which lands differ from one another. By altitude and depth: altitude renders coldness, depth renders the contrary. From the proximity of mountains, these things happen: if they are on the southern side, the land will be cold, for southern mountains block the winds, and northern winds seek it with cold blasts. If the north side has mountains, it will be the contrary of the higher cold. By proximity to the sea: the south provides a hot and dry land, the north a cold and dry one. Moreover, lands differ among themselves by their own nature. For if the land is rocky, it is cold and dry; if it is rich and thick, it is hot and moist; if muddy, it is cold and moist. The air is also changed by fumes, that is, by the decay or rot of something, from which diseases and plagues arise in humans.

Concerning exercise of the body.

Exercise changes the body, for since it is equal, it provides equal heat; when it becomes more intense, it heats more, but afterwards, it cools and desiccates. Idleness changes the body, for if it is unequal, it makes coldness and moistens every unequal thing; if it is equal, it does so equally.

Concerning the division of baths.

Baths are of sweet water or non-sweet. A bath of sweet water softens; if hot, it heats; if cold, it cools. A bath of non-sweet water desiccates the body. For if it is from salty or bitter or sulfurous water, it heats and desiccates; if it is from aluminous or gypsum-based water, it cools and desiccates.

Concerning the modes of foods.

There are two modes of foods. There is food that generates good humor, and there is bad food that generates bad humor. Good food is that which creates good blood and is equal in mixture and operation, such as clean, fresh, fermented bread, and the meat of a yearling lamb and kid. Bad food performs the contrary, such as stale, fermented bread, and old beef or goat meat. Furthermore, there are two modes of food that create good and bad humor: heavy and light. Heavy is pork and beef; light is the meat of chickens or medium-sized fish that are more mobile and less fatty and scaly. There is also a kind of vegetable that generates bad humor, i.e., red bile, such as nasturtium, mustard, and garlic. There are those that generate melancholy, such as lentils, cabbage, and old goat meat or beef. And there are those that generate phlegm, such as the meat of piglets and lambs, purslane, and orach. Furthermore, heavy food generates phlegm and black bile; light food generates red bile; both are bad.

Concerning the modes of drinks.

There are three modes of drinks. There is a drink that is nothing other than drink, such as water; and there is a drink that is both drink and food, such as wine. And there is another drink that pertains to both of the above, such as a potion given against some defect of disease, such as honey-water or mulsum honeyed wine.