188 COSMOS. 



quest, in the very year .before his death, with theoretical in- 

 vestigations upon the question, how in the elevation of 

 mountains and alterations in the surface of the earth, the 

 isothermal surfaces are brought into equilibrium with the 

 new form of the .soil. The lateral radiation from strata 

 which lie in the same level, but are differently covered, 

 plays in this case a more important part than the direction 

 (inclination) of the cleavage planes of the rock, in cases 

 where stratification is observable. 



I have already elsewhere mentioned* how the hot springs 

 in the environs of ancient Carthage, probably the thermal 

 springs of Pertusa (aqua calidce of Hammam-el-Enf), led 

 Bishop Patricius, the martyr, to the correct view of the 

 cause of the higher or lower temperature of the bubbling 

 waters. When the Proconsul Julius tried to confuse the 

 accused bishop by the mocking question, " Quo auctore fer- 

 vens ha : c aqua tantum ebulliat?" Patricius set forth his the- 

 ory of the central heat, " which causes the fiery eruptions of 

 ./Etna and Vesuvius, and communicates more and more heat 



* With regard to this passage, discovered by Bureau de la Malle, 

 see Cosmos, vol. i., p. 223, 224. "Est autem," says Saint Patricius, 

 " et supra nrmamentuin cajli, et suiter terrain ignis atque aqua ; et 

 quae supra terrain est aqua, coacta in unum, appellationera marium : 

 qua? vero infra, abyssorum suscepit; ex quibus ad generis human! 

 usus in ten-am velut siphones quidam emittuntur et scaturiunt. Ex 

 iisdem quoque et thermae exsistunt : quarum qua? ab igne absunt 

 longius, provida boni Dei erga nos mente, fngidiores ; quae vero pro- 

 plus admodum, ferventes fluunt. In quibusdam etiam locis et tepida; 

 aquae reperiuntur, pro ut majore ab igne intervallo stint disjuncta?." 

 So run the words in the collection : Ada Primorum Martyrum, opera 

 et studio Theodorici Rtdnart, ed. 2, Amstelaedami, 1713 fol., p. 555. 

 According to another report (A. S. Mazochii, in vctus mannoreum 

 sanctce Neapolitans Ecclesice, Kalendarium commentarius, vol. ii., Xeap. 

 1744, 4to, p. 385), Saint Patricius developed nearly the same theory 

 of telluric heat before the Proconsul Julius ; but at the conclusion of 

 his speech the cold hell is more distinctly indicated : " Xam qiue lon- 

 gius ab igne subterraneo absunt, Dei optimi providentia frigidiores 

 erumpunt. At qua? propiores igni sunt, ab eo fervefactae, intolerabili 

 calore praeditas promuntur foras. Sunt et alicubi tepida;, quippe non 

 parum sed longiuscule ab eo igne remotae. Atque ille infernus ignis 

 impiarum est animamm carnificina ; non secus ac subterraneus frigi- 

 dissimus gurges, in glaciei glebas concretus, qui Tartarus nuncupatur." 

 The Arabic name, Hammdm-el-Enf, signifies nose-baths, and is, as Tem- 

 ple has already remarked, derived from the form of a neighboring 

 promontory, and not from a favorable action exerted by this thermal 

 water upon diseases of the nose. The Arabic name has been various- 

 ly altered by reporters : Hammam 1'Enf or Lif, Emmamelif (Pey?- 

 sonel), la Mamelif (Desfontaines). See Gumprecht, 

 kn avfdem Fcstlande von Africa (1851), s. 140-144. 



