The Summary of Physics Restored

212Rarefaction and condensation are two instruments of Nature by which bodies are changed into spirits and spirits back into bodies, or bodily elements into spiritual ones and spiritual ones again into bodily ones. For the elements undergo these alternations in mixed bodies. Thus Earth supplies spiritual food from her bosom to the roots of plants. Once consumed, it passes into stem, bark, branches, leaves and flowers—in a word, into bodily substance. Nature does the same in animals. The food and drink they consume, at least their better portion, are brought into humours and finally spirits. Entering through the pores and adhering to flesh, sinews, bones and the other bodily parts, these nourish and enlarge them, restoring declining nature through the tireless work of replacement. Thus a portion of spiritual and purer substance thickens and coagulates into the foamy body of seed. Art, Nature’s imitator, experiences something similar in its dissolutions and compositions.