222 M. Arago on Artesian Wells 



of water, hut a real lake, with the fishes and ducks which fre- 

 quent the common lakes of the country. 



I shall not wander from that path in which I wish to direct 

 the reader, if I show, by one or two quotations, that Carniola is 

 not the only country where subterranean expanses of water are 

 found which are frequented by fishes. It is a fact that France 

 possesses, though on a much more limited scale, lakes similar to 

 that of Zirknitz ; so that this last can never be regarded as merely 

 accidental, or a singular anomaly without any assignable cause; 

 on the contrary, it will take its place amongst those regular phe- 

 nomena whose existence is connected with the nature of the soil 

 and the geological constitution of the globe. 



I borrow my first quotation from a work which is nearly a 

 century old, the Memoires de VAcademie des Sciences of 1741. 

 In the 37th page, I find that there is at Sable in Anjou, in the 

 midst of a kind of moor, a spring, or rather a kind of pit, of 

 some twenty or twenty-five feet in diameter, and whose depth 

 no one has been able to determine. This spring, known in the 

 neighbourhood under the name of the unfathomable fountain, 

 sometimes overflows, and then there issues from it a prodigious 

 quantity of fish, and especially of trouts of a peculiar species. 

 *' There is ground to think," remarks the Secretary of the Aca- 

 demy, " that the whole of this locality is formed of the vault of 

 a lake which is situated underneath."" 



At the other extremity of France, in the department of Haute 

 Saone, near to Vesoul, there is a natural pit called Frais Puits, 

 which presents phenomena precisely similar. In summer and 

 autumn, when it has rained heavily for two or three days with- 

 out intermission, the water appears and boils over at the open- 

 ing of the Frais Puits, and forms a real torrent, tvhich spreads 

 over all the neighbouring country. After this flood, which lasts 

 only for a few hours, pike are sometimes found in the fields and 

 meadows which had been inundated. 



Even in fiat countries there are caverns into which whole rivers are 

 engulfed. 



This phenomenon in a high degree excited the attention of 

 the ancients. Thus even Pliny mentioned as among the rivers 



