750 DESCRIPTIVE GEOLOGY. 



is no supply of fresh watei* from the snrfacej and at the time of our visit, in 

 August, the water was much mote dense than in the larger lake. Over a 

 greater part of the surface was found a thick incrustation of trona strong 

 enough to bear up a man, under which is a greenish slime and occasional 

 pools of water. One charactenstic feature of the shore is the green and 

 purplish tints of the moist sands, which, upon being dried, present the usual 

 earthy colors. 



Gay-Lussite similar to that found in the large Soda Lake also occurs 

 here, and is formed in the same manner. ' 



The trona from the small Soda Lake, upon being subjected to analysis, 

 yielded the following : 



Sulphate of soda 0.99 



Chloride of sodium. 1,10 



Carbonate of soda 66.27 



Water and free carbonic acid 28.83 



Insoluble residue 2.81 



100.00 



It gave, after concentration by crystallization, in the spectroscope, both 

 potassa and lithia. There is also present a trace of phosphoric and boracic 

 acids. The insoluble residue is sand, with traces of lime, iron, and phos- 

 phoric acid. 



