6 FIRESIDE SCIENCE. 



the temperature is uniformly high. The gases 

 present are usually carburetted hydrogen, and some- 

 times sulphuretted hydrogen is evolved freely, giv- 

 ing to the water the smell of stale eggs. The tem- 

 perature of the water depends in a great measure 

 upon the depth of the boring. The well at St. 

 Louis delivers water at a temperature above 100 

 F., and the water of most other wells is found above 

 70 F. In winter such water, if pure, would be 

 delightful for washing purposes, but for drinking it 

 would be vapid and nauseous. It is also without 

 atmospheric air, and would need not only to be 

 cooled but to be aerated to fit it for table use. 

 Altogether we may conclude that the deep springs 

 are not very promising sources from which to obtain 

 potable waters. 



It has been remarked that the water from ar- 

 tesian wells is derived from great distances. This 

 was shown in a boring at Tours, France, from 

 which, when the borer was withdrawn, quantities of 

 sand and small snail-shells were ejected, which with- 

 out doubt found their way there from the moun- 

 tains of Auvergne, thirty miles distant. Eels and 

 small fish have been found in the water of artesian 

 wells, which shows that there is sometimes direct 

 communication through the strata with distant 

 ponds or superficial accumulations of water. The 

 water which falls upon inland mountains and hills, 



