66. But let this be illustrated by analogies taken from the three kingdoms of nature, called the animal, plant and mineral kingdoms.
From the animal kingdom: When food has been turned into chyle, the blood vessels extract and produce from it their blood, the nerve fibers their fluid, and the substances from which the fibers originate their animal spirit.
From the plant kingdom: A tree rests with its trunk, branches, leaves and fruit upon its root system, and through its roots it draws and extracts from the ground its sap — a less refined sap for its trunk, branches and leaves, a purer one for the flesh of its fruit, and a still more refined one for the seeds within the fruit.
From the mineral kingdom: We find in some places in the ground’s embrace minerals infused with gold, silver and iron. From exhalations deep within the earth gold derives its element, silver its element, and iron its element.
