310 
GEOLOGY. 
the influence of the sun and air alone. It is reported that great deposits of salt, formed in this 
way by the action of the sea, have been found on islands in the Gulf of California, and are now 
being worked. Even Vizcaino, in his narrative as long since as 1602, noticed the numerous 
deposits of salt in Lower California. 
CARBONATE OF SODA. 
Carbonate of soda occurs at many places, associated with salt and sulphate of magnesia, hut 
has not been observed in crystals, or so isolated from other salts as to be specifically recognized. 
It occurs, with other salts, at the borders of Kern Lake, Tulare Valley ; in incrustations on 
the bottom-land of the Santa Anna River, near San Bernardino ; in the soil along the Mojave 
River, Great Basin, and in the incrustation of the Soda Lake, at the end of the Mojave River. 
The last locality is the most important, and is an extensive deposit, but is not very thick. A 
portion of the crust taken from the lake gives a strongly alkaline solution, which contains: 
Carbonate of soda. 
Chloride of sodium. 
Sulphate of magnesia, (trace.) 
Carbonate of lime, (little.) 
Efflorescences of soda, and crusts upon dry lakes, are common in Egypt, Asia, and elsewhere, 
in semi-desert regions. 
