M. Vitruvius per Iocundum solito castigatior factus cum figuris et tabula ut iam legi et intelligi possit

...from the other side, near Cortyna, they do not have an apparent spleen. Hence, even physicians inquiring about this matter found in those places an herb which, when the cattle ate it, reduced their spleens; by collecting that herb, they cure those with enlarged spleens with this medicine, which the Cretans also call asplenion spleen-wort. From this, it is possible to know that by food and water, the properties of places are naturally pestilent or salubrious. Likewise, if walls are established in marshes, which marshes are next to the sea and look toward the north, or between the north and the east, and those marshes are higher than the sea shore, they will appear to be established by reason. For by ditches being dug, the exit of water is made to the shore; and when the sea is increased by storms, the redundancy of water flowing back into the marshes is stirred by motions; and with bitter mixtures, it does not allow the genera of marsh beasts to be born there; and whatever comes swimming from the upper places near the shore is killed by the unaccustomed saltiness. A model of this thing can be the Gallic marshes, which are around Altinum, Ravenna, Aquileia, and other municipalities that are in such places near marshes, which have incredible salubrity by these reasons. But those for which there are marshes upon which they sit, and which do not have flowing exits, neither through rivers nor through ditches, like the Pontine marshes, they rot, and emit heavy and pestilent humors in these places. Likewise, in Apulia, the old town of Salapia, which Diomedes built returning from Troy, or (as some have written) Elphias the Rhodian, had been placed in such places, from which the inhabitants, suffering annually from sickness, finally came to M. Hostilius; and asking publicly from him, they obtained that he should search for and choose a suitable place to move the walls. Then he did not delay, but immediately, with most learnedly sought reasons, bought a possession next to the sea in a salubrious place; and asked from the Roman Senate that it be allowed to move the town, and he established the walls, and divided the areas, and gave them to each municipality by right. With these finished, he opened a lake into the sea, and made a port from the lake for the municipality. Thus, now the Salapini, having progressed four miles from the old town, live in a salubrious place.

Concerning the foundations of walls and towers. Chapter V.

Therefore, when salubrity has been explained by these reasons in the placement of walls, and regions have been chosen that are abundant in fruits to feed the city, and they have had roads, or the convenience of rivers, or sea transport through ports for the expedited transport of goods to the walls, then the foundations of towers and walls are to be made so that they are dug (if they can be found) to solid ground, and in the solid (as much as seems necessary from the size of the work for the ratio) of greater thickness than the walls which are to be above ground, and they are filled with the most solid structure. Likewise...

A small marginal note in ink, likely a later hand, points to the text regarding the marshes.