[1630]. Geop. ii. 9. In these rich loams, particularly on the banks of the Stymphalian and Copaic lakes, wheat has been known to yield a return of fifty-fold. Thiersch, Etat Act. de la Grèce. t. ii. p. 17.
Other spots, again, return thirty-fold. Sibth. in Walp. Mem. i. 60.
[1631]. The pitch-pine indicated a light and hungry soil; the cypress, a clayey soil. Philost. Icon. ii. 9. p. 775.
[1632]. Geop. ii. 11.
[1633]. The Grecian husbandman, therefore, when planting palm-trees in any other than a sandy soil, sprinkled salt on the earth immediately around. Theoph. Hist. Plant. i. 6. 2.
[1634]. Geop. ii. 10.
[1635]. Xenoph. Anab. ii. 3. 16. The doom-palm, generally, I believe, supposed to be peculiar to Upper Egypt and the countries beyond the cataract, was anciently cultivated also in Crete. Theoph. Hist. Plant. i. 6. 3.
[1636]. Geop. ii. 4, sqq.
[1637]. Philost. Icon. ii. 9. p. 775.
[1638]. Spallanzani, in his scientific Travels in the Two Sicilies, describes and explains the cause of the rarity of springs in volcanic countries. In some districts among the roots of Ætna the female peasants are compelled to travel ten miles, at certain seasons of the year, in search of water, a jar of which costs, consequently, almost a day’s journey. vol. i. p. 299, sqq. In another part of the same work he investigates the origin of springs in the Æolian isles, which he illustrates by the example of Stromboli. iv. 128. In this island there are two fountains, one of slightly tepid water, at the foot of the mountain, the other on its slope. “Je recontrai,” observes Monsieur Dolomieu, “à moitié hauteur une source d’eau froide, douce, légère et très bonne à boire, qui ne tarit jamais et qui est l’unique ressourse des habitans lorsque leurs cîternes sont épuisées et lorsque les chaleurs ont desséché une seconde source qui est au pied de la montagne ce qui arrive tous les étés.” He then adds with reason: “Cette petite fontaine dans ce lieu très élevé au milieu des cendres volcaniques, est très remarquable, elle ne peut avoir son réservoir que dans une pointe de montagne isolée, toute de sable et de pierres poreuses, matières qui ne peuvent point retenir l’eau, puisqu’elles sont perméables à la fumée.” Voyage aux Iles de Lipari, t. i. p. 120. He then endeavours to account for its existence by evaporation. In the island of Saline, among the same Æolian group, there is another never-failing spring, which, as some years no rain falls in these islands during the space of nine months, has greatly perplexed the theories of naturalists. Spallanzani conceives, however, that the phenomenon may be explained in the usual way: “It appears to me,” he says, “extremely probable, that in the internal parts of an island which, like this, is the work of fire, there may be immense caverns that may be filled with water by the rains; and that in some of these which are placed above the spring, the water may always continue at nearly the same height.” Travels in the Two Sicilies, vol. iv. p. 136.