30 GEOLOGICAL MEMOIRS. 



it contains 30' 63 of a mixture of salts in the following propor- 

 tions : — 



Sulphate of soda 18*18 



Carbonate of soda 12*08 



Chloride of sodium 69*73 



Traces of magnesia and a little manganese. 



On my retutn to my quarters between the Great and Little Ararat, 

 part of a bottle containing the solution became filled with beautiful 

 crystals of Glauber-salt, which only partially again dissolved in the 

 higher temperature of the Araxes plain. 



In the immediate vicinity of these red lakes a number of small 

 pools occur on the same level, distinguished by the absence of all 

 salt-crusts and by the wine-yellow colour of their alkaline waters. 

 These small lakes are true reservoirs of carbonate of soda, and thus 

 undoubtedly the most interesting phsenomenon of this singular 

 locality. 



This alkaline solution contained in 100 parts 34*70 parts of a salt 

 with the following composition : — 



Carbonate of soda 68*90 



Sulphate of soda 15*55 



Chloride of sodium 1 5* 50 



In the bottle containing a quantity of this solution, a tabular 

 crystalline mass of carbonate of soda, occupying nearly the whole 

 volume of the fluid, formed in the same circumstances as in the 

 saturated solution of Glauber-salt mentioned above. 



Two or three wersts from these lakes, in the prolongation of the 

 valley, where it expands into the plain of the Araxes, two other lakes 

 of considerable size occur. The larger, with an area of five or six 

 square wersts, extends even beyond the valley, the widest part lying 

 in the plain. These lakes much resemble that of Tasch-burun, but 

 in a solution of equal strength the amount of Glauber-salt and car- 

 bonate of soda is greater than in the latter. 



The existence of these lakes as perennial receptacles of water 

 depends evidently on the Karassu-springs, which issuing from below 

 the lava, form small reedy marshes, and, uniting their waters in broad, 

 shallow hollows, expose an extensive surface to rapid evaporation. 

 The lake of Tasch-burun, which has no outlet, probably originate in 

 the same cause, acting at the bottom of the basin. There can be no 

 doubt, that within the district occupied by these lakes, an immense 

 quantity of Glauber-salt and soda in a solid form as an anhydrous salt, 

 could be collected in a short time and at a comparatively small 

 expense. J. N. 



