Scientific Intelligence — Geology. 385 



maly, I would allude more particularly to the fact by which the 

 pit of Neuffen is especially distinguished from the other pits regard- 

 ing which we are in the possession of comparative observations. The 

 products of numerous basaltic eruptions are to be seen around Neuf- 

 fen, both at the foot and on the plateau of the Alp. The eruption 

 of basalt in the Alp of Wiirtemberg is of very modern date ; for, as 

 Mandelslohe long ago pointed out, in his important essay on that 

 district,* it was posterior to the deposition of the fresh-water forma- 

 tion, so rich in the remains of quadrupeds, which is found in various 

 parts of the Alp. The calorific action which the igneous rock has 

 exercised on the surrounding limestone, is evident from the crystal- 

 line texture, and often from the bacillary structure of the latter. If 

 we reflect on the slowness with which heat moves from deeply heated 

 regions across masses having such a low degree of conducting power 

 as rocks possess, we need not be surprised at finding that the heat 

 communicated by the basalt to the Jurassic stratified beds, has not 

 been yet entirely dissipated by radiation in space, at all events, at a 

 certain depth. It is, on the contrary, remarkable, that hitherto the 

 thermometrical traces of the heat of these ancient igneous rocks have 

 not been pointed out at any other locality. Such, then, seems to 

 me to be the cause of the abnormal increase of temperature noticed 

 at Neuffen. M. Leopold Pilla, in giving an account of the remark- 

 ably elevated temperature which he, along writh Messrs Matteucci 

 and Bunsen, observed at Monte Massi, states it to be his opinion, 

 that the high temperature of the bottom of that pit is not the effect 

 of a local plutonic influence, but that the central igneous nucleus 

 nmst be nearer the terrestrial surface in Italy than in England; but 

 there is no circumstance which induces me to extend this hypothetical 

 explanation to Wiirtemberg.t As to the very considerable increase 

 observed at Jakoutysk,J in Siberia, in a very recent formation, and 

 where there is constant congelation, it must, in all probability, be 

 attributed to another cause, and most likely to the degree of conduc- 

 tibility of the frozen beds traversed by the pit.§ 



25. Subsidence of the Land at Puzzuoli. — ^Mr J. Smith has stated 

 to the British Association, that when he visited the temple of Jupi- 

 ter Serapis at Puzzuoli, in March 1819, its floor was elevated about 

 6 inches above the level of the sea ; but on the 11th of May, in the 

 year 1845, it was covered to the depth of 18 inches at low-water, 

 and 28} at high tide, — the sea being calm at the time. The cus- 

 tode of the building told Mr Smith that this change was progressive, 

 amounting to 1^ English inch per annum. The cicerone, too, who 

 had exercised his profession for thirty years, said, he knew a differ- 

 ence of at least 3 feet 6 inches in the height of the sea upon the 



* Memoircs de la Society, du Museum d'Histoire NatureUe de Strasbottrp. 

 + Comptes Rendus de V Academic des Sciences^ 1843, tome xvi., p. 1326. 

 J Annales des Mines de liiissie, 1838, p. 343. 

 § Comptes Rendu?, 1845, 2'>»»« Scmestrc, No. 24, p. 1335. 



