‹‹‹ Vitr. 5.9.4 | Table of Contents | Vitr. 5.9.6 ›››
5The central space between the porticos should be ornamented with verdure, inasmuch as hypæthral walks are very healthy; first, in respect of the eyes, because the air from green plants being light and volatile, insinuates itself into the body when in motion, clears the sight, and, removing the gross humours from the eyes, leaves the vision clear and distinct. Moreover, when the body is heated by the exercise of walking, the air, extracting its humours, diminishes corpulency, dissipating that which is superabundant in the body.
5The space in the middle, between the colonnades and open to the sky, ought to be embellished with green things; for walking in the open air is very healthy, particularly for the eyes, since the refined and rarefied air that comes from green things, finding its way in because of the physical exercise, gives a clean-cut image, and, by clearing away the gross humours from the eyes, leaves the sight keen and the image distinct. Besides, as the body gets warm with exercise in walking, this air, by sucking out the humours from the frame, diminishes their superabundance, and disperses and thus reduces that superfluity which is more than the body can bear.