748 DESCRIPTIVE GEOLOGY. 



The combination of acids Avith bases gives : 



Chloride of sodium 64.9413 



Sulphate of soda 13.7626 



Carbonate of soda .' 29.2482 



Sulphide of sodium 0.2384 



Sulphate of potassa 3.6515 



Carbonate of magnesia 0.0652 



Sihca 0.2050 



Excess of carbonic acid 0.4658 



112.5780 



Before concentration, the water gave with tumeric paper a reaction for 

 boracic acid ; after crystallization, the spectroscope revealed the presence 

 of lithia. 



The northwest side of the lake being quite shallow, the receding waters 

 leave large fields of dazzling- white carbonate of soda, which by the g,utumn 

 accumulates to such an extent as to become an article of commerce, 150 

 tons of the crude salt collected in one season from the two lakes having 

 been freighted to Carson City, Nevada, and, it is said, sold at S40 per ton 

 to the soap-manufacturers. 



An analysis by Prof 0. D. Allen, of a sample taken from the deposit, 

 shows that it is quite a pure trona, or sesquicarbonate of soda, mixed with 

 small quantities of sulphate of soda and common salt. It yielded the fol- 

 lowing : 



Soda 40.55 



Carbonic acid 36.86 



Sulphuric acid 0.73 



Chlorine 0.98 



Water , 19.90 



Insoluble residue » 0.80 



99.82 

 Oxygen eq. to chlorine 0.22 



99.60 



