The Anatomy of Melancholy

Attraction is an assisting faculty that draws food into the stomach as a lodestone draws iron, or a lamp draws oil. This attractive power is essential in plants, which suck moisture through their roots as through a mouth, into the sap as into a stomach. Retention holds the food once it has been drawn into the stomach, until it is digested; if it passed straight through, the body could not be nourished.

Digestion is performed by natural heat: as a torch’s flame consumes oil, wax or tallow, so natural heat transforms and digests the nutritive matter. Its opposite is indigestion, caused by insufficient natural heat. There are three kinds of digestion: ripening, boiling and roasting.

Ripening is especially evident in the fruit of trees, which is said to be ripe when its seeds are ready to be sown again. Its opposite is rawness or incomplete digestion, to which gluttons, lovers of luxury and idle people are especially prone. They take no exercise to kindle their natural heat, or else smother it as too much wood puts out a fire.

Boiling is the simmering of food in the stomach through this natural heat, as food boils in a pot; its opposite is corruption or putrefaction. Roasting is the processing of internal moisture by heat; its opposite is incomplete roasting.

Besides these three operations of digestion, there is a fourfold sequence of digestive processing: mastication, or chewing in the mouth; the conversion of chewed food into chyle in the stomach; third, its conversion in the liver from chyle into blood, called sanguification; and last, assimilation, which takes place in every part. Expulsion is the power of nutrition that eliminates all surplus waste and remnants of food and drink through the intestines, bladder and pores: by purging, vomiting, spitting, sweating, urine, hair, nails and so on.

As the nutritive faculty nourishes the body, so the faculty of growth—the second operation or power of the vegetative faculty—increases its size in every dimension, length, breadth and thickness, until it reaches its proper proportions and complete form. It has its appointed period of growth, as it does of decline, and that is certain, as the poet observes:

Each has his appointed day; for everyone The time of life is brief and cannot be restored.

A span of life is set for everyone; It is but short, and none can live beyond it.

The last of these vegetative faculties is reproduction, which through seed produces another like itself, perpetually preserving the species. They assign three subordinate operations to this faculty, the first being to turn nourishment into seed, and so on.

Necessary accompaniments or conditions of this vegetative faculty are life and its absence, death. Natural heat is essential to preserving life, though dryness, moisture and the other primary qualities also play a part. This heat exists in plants too, as their growth and fruiting show, although it is harder to perceive. In every body it needs innate moisture to sustain it and prevent its exhaustion. Our climate, country, bodily constitution, and good or bad management of the six non-natural things contribute greatly to its preservation.