20 Tlie Alkaline Lakes of California. [Jan., 



In tlie foregoing analysis all the salts have been calculated as 

 being anhydrous; but crystallized borax contains about 47 per 

 cent, of water, and hence the 281 * 48 grains found will correspond 

 to 535 ■ 08 grains of crystallized salt. Besides the amount of biborate 

 of soda contained in the mud of the lake, its waters are therefore 

 capable of affording at least 6000 additional tons. 



The borax, being the least soluble salt present in any consider- 

 able quantity, has evidently been deposited in the form of crystals 

 in the mud at the bottom; and that the process is still rapidly 

 going on is shown by the coating of crystals formed upon sticks or 

 other substances immersed for a short time in the watei's of the 

 lake. A consideration of the phenomena attending the production 

 of borax further leads to the behcf that its formation is effected by 

 the decomposition of carbonate of soda by boracic acid emitted from 

 sources beneath its bed, and large quantities of carbonic acid con- 

 stantly escape from the surface of the water. Should this be the 

 case, it is more than probable that any moderate extraction of 

 borax mil be fully compensated for by the formation of that salt 

 constantly taking place. 



The waters of another lake situated in a little valley a few 

 miles north-east of Clear Lake, and surrounded by a thick forest 

 of oak and pine, are also known to contain borax. The bottom of 

 this lake, which covers an area of about twenty acres, consists of a 

 clay similar to that found in the larger one ; but although it con- 

 tains large quantities of borax in solution, no crystals of that salt 

 have as yet been found in the mud. In addition to the localities 

 already mentioned, there are numerous springs in the vicinity of 

 the lakes, the waters of which are more or less imjjregnated with 

 borax. 



To the north-east of Borax Lake, and about a mile from it on 

 the borders of Clear Lake, is a large depi^sit of sulphur where 

 solfatara action is still apparent. The volcanic rocks have here 

 been extensively fissured and decomposed, and from the various 

 orifices steam and sulphurous vapours are constantly issuing. The 

 amount of sulj^hur which has been deposited in this place is very 

 large, covermg an area of several acres, but the depth to which it 

 may extend can only be ascertained by the further development of 

 the excavations now in progress. 



From six to eight tons of this sulphur are refined daily by dis- 

 tillation in large iron retorts, after which it is used for the manu- 

 facture of sulphuric acid, and in gunpowder, match, and other 

 factories. The most interesting fact in connection with this deposit 

 is the association of cinnabar with the sulphur sometimes distinctly 

 separated from it, in quartz, evidently of recent origin and deposited 

 from solution, but more frequently thoroughly intermixed with the 

 mass. 



