246 M. Arago on Artesian Wells, ^c. 



burnt. Streets, halls, and work-shops, were thus illuminated, 

 and it was conducted to the spot required through the medium 

 of tubes constructed of the bamboo. 



There are in the United States of America many villages in 

 which, for the purpose of illuminating the streets and the houses, 

 those streams of gas are employed, which are without intermis- 

 sion disengaged, and for a great number of years, from the 

 openings which iiad been made in search of water * 



Usually the reservoirs of gas contained in the bowels of the 

 earth cannot furnish a supply of any long continuance. At Cor- 

 meilles, in the department of Seine-et-Oise, there was so abun- 

 dant a discharge of hydrogen gas, through an opening made, un- 

 der the direction of M. Degousee, whilst sinking a well, that the 

 workmen could not work during a whole day. After three or 

 four days, however, all traces of it had disappeared. This phe- 

 nomenon, accompanied with very much the same circumstances, 

 has also very lately occurred at Trieste. -f- 



Some Remarks on the Subterranean Course of Water, and on 

 the Absorption of Gases by Water in the Inteiior of tfie 

 Earth. By Gustav Bischof. 



In reference to the subterranean course of water, we must dis- 

 tinguish the following cases : — 



1. The water which is afforded by the atmosphere filters 

 through permeable layers of earth and rock, and arrives at stra- 

 ta which resist its passage. If these strata reach the surface at 

 a lower point, the water makes its appearance in the form of 

 springs. 



In such a case, it is not necessary that the water should en- 

 tirely fill the canal ; but it can, like a subterranean rivulet, flow 

 down in contact with atmospheric air. This is the case more par- 



• The following passage occurs in Pliny. " There arises perpetually from 

 Mount Chimera, near Phaselis, a flame which burns night and day." Captain 

 Beaufort found this flame in 1811. It is evidently the result of the disen- 

 gagement of gas by some natural fissure of the earth. Its antiquity and con- 

 tinuance seemed to justify its quotation here. 



-}• Annuaire pour I'An 1835. 



