316 On Spring and liwer Wdter, its 



the Rhone contains at Lyons is very considerable in amount. 

 Experiments made in the year 1839 gave the following re- 

 sults. 



Quantity of dry residuum, 

 per 1.76 lb. (per litre). 



First Experiment — The flood of the river being ad- 

 vancing, 12 grains. 



Second Experiment — The flood of the river being at its maxi- 

 mum, 18 grains. 



Third Experiment— »The flood past and the river diminishing, 7 grains. 



Thus, at the maximum of the flood, the quantity of mud to 

 be separated from the 1,500,000 gallons of water regarded 

 necessary every twenty-four hours, would be about 22,000 

 pounds (8800 kilogrammes) ; and it is not easy to comprehend 

 how the filters could be cleared out. If estimated by volume, 

 it would amount to about 1250 cubic feet of solid matter per 

 diem. 



The process of natural infiltration across the soil on the 

 margin of the river, and of the great drain-wells whence the 

 water is procured, which appears at first sight as the most 

 convenient, has the disadvantage of decidedly diminishing the 

 purity of the water. Thus, the author has found that the 

 wells which are at the distance of from fifteen to twenty yards 

 from the bed of the Rhone, supply water which contained cal- 

 careous sulphates and chlorides, and decomposed the solution 

 of soap. 



A preference is also due to spring- water on the score of 

 temperature. Such water may run for a great distance over 

 the surface, without losing much of that equality of tempera- 

 ture which makes it cool in summer and warm in winter. 

 The author quotes, in reference to this curious subject, the 

 Lavosne spring at Neuville, which takes two hours and forty- 

 four minutes to reach the Saone, and whose waters, neverthe- 

 less, never freeze, even urder the most intense cold ; and, on 

 the other hand, are never heated more than five or six degrees 

 Fahr. above their original temperature. 



The water of the Rhone, which at Lyons varies very much 

 as the atmosphere does, never seems decidedly to cool down in 

 its passage through the pipes of the conduit, by which it 

 reaches the wells and fountains. Thus in 1839, from the 



