1856.] RICHARDSON AND BROWELL — MINERAL WATERS. 



185 



has been depositing for hundreds of years. Abich has also furnished 

 some particulars of similar waters of some lakes near Ararat. The 

 mineral springs which supply the Laacher-See and the mineral water 

 of Roisdorf, near Bonn, have all a similar composition, although, of 

 course, not so rich in saline matter as the waters of these lakes, 

 which approach, in fact, the character of mother-liquors : having no 

 outlet, with a constant evaporation under a powerful sun, the saline 

 matter accumulates, until the water can no longer hold it in solution, 

 and then the usual deposits on the bottom and sides are formed to a 

 depth of several inches. 



The only analysis of the water of Lake Van with which we are 

 acquainted is that of De Chancourtois, who found a potash-salt ; and 

 this is not unlikely to be present, as potash and soda so often ac- 

 company each other. The detection of potash is difficult when pre- 

 sent in small quantities, and in our experiments on a limited supply 

 no trace could be found. 



We add a Table giving the composition of some of the above- 

 mentioned waters in 10,000 parts. 



Constituents. 



1. 



2. 



3. 



4. : 5. 



6. 



Carbonate of soda 



86-1 



33-3 



93-8 



5-5 



"5-5 



traces 



1-8 



9-8 



6-9 



49-9 



37-0 



55-7 



213-6 



1-1259 Q-niisn 



9-453 



4-481 

 17-896 



3-169 



2-804 



-105 



-207 



Sulphate of soda 



•0959 

 •1791 



•'5398 



•2112 



(carb.) 



31767 

 5-0241 



2-6885 

 2-9269 



Chloride of sodium 



Sulphate of potash 



Carbonate of lime 



Carbonate of magnesia ... 

 Oxide of iron 



Silica 



-0295 : -4968 





Total 



226-9 



66-6 



306-3 



2-1814 



23-5197 



38-115 









1. Water from the Lake of Van, analysed by De Chancourtois. 



2. Water from a lake near Taschburun, analysed by Abich. 



3. Water from a lake to the S.E. of the smaller Ararat, analysed 

 by Abich. 



4. Water from the Laacher-See, analysed by Bischof. 



5. Mineral water from Hepping, analysed by Bischof. 



6. Mineral water from Roisdorf, analysed by Bischof. 



The inference is therefore very direct, that the source of the con- 

 stituents of your waters, Nos. 6 to y, must be similar to those which, 

 like the above, take their origin in volcanic districts. The decompo- 

 sition of the different felspars, especially such as labradorite, which 

 contain more soda than potash, by the action of water containing 

 carbonic acid in solution, at once explains the composition of the 

 waters from the Lakes Van and Ardchek. 



The difference in the composition of the water from the same 

 lake probably arises from the action of the osmotic force, which was 

 the subject of the Bakerian lecture by Graham in 1854. 



