CHEMICAL COMPOSITION OF THE WATER OF SALTON SEA. 



45 



It is seen that the waters listed in table 15 may be conveniently divided into four 

 groups, as follows: 



(1) Chloride waters in which sodium chloride is the principal constituent as illustrated 

 in ocean water, the water of Great Salt Lake, and the original Salton Sea. 



(2) Chloride-sulphate waters in which both chlorides and sulphates predominate. 

 The water of the Caspian Sea is the only representative of this group given in the table. 



(3) Chloride-sulphate-carbonate waters which contain notable amounts of carbon- 

 ates as well as sulphates and chlorides. To this group belong the waters of the Salton 

 Sea and the southwestern rivers of which analyses are given in the table. All are of the 

 same general type, in that each contains considerable quantities of sodium, calcium, and 

 magnesium, as well as the three acid radicles. 



Table 15. — Comparing the composition of the water of the Salton Sea with other natural waters. 



A. Salton Sea. According to analysis of 1907. 



B. Original Salton Sea. Supposed composition as calculated from excess of constituents of present lake in 1907 over that found 



for Colorado River. 



C. Colorado River at Yuma. Mean of seven analyses, made at intervals of about two months, of composites of samples col- 



lected almost daily between Jan. 10, 1900, and Jan. 24, 1901. Analyses by R. H. Forbes and W. W. Skinner, Bull. Ariz. 

 Agri. Expt. Sta., No. 44 (1902). 



D. Gila River at head of Florence Canal, Ariz. Mean of four analyses of composites representing samples collected daily for 



seven, five, four, and five weeks, respectively, at intervals between Nov. 28, 1899, and Nov. 5, 1900. Analyses by R. H. 

 Forbes and W. W. Skinner, loc. cit. 



E. Salt River at Mesa, Ariz. Mean of six analyses of composites representing samples collected daily for four, one, four, 



ten, thirteen, and eight weeks, respectively, between Aug. 1, 1899, and Aug. 4, 1900. Analyses by R. H. Forbes and 

 W. W. Skinner, loc. cil. 



F. Rio Grande at Las Cruces, N. M. Mean of twelve consecutive monthly analyses of composites of samples collected daily 



from June 1, 1893, to June 1, 1894. Analyses by Arthur Goss, Bull. N. M. Agri. Expt. Sta., No. 34 (1900). 



G. Ocean water. Mean of 77 analyses by W. Dittmar, H. M. S. Challenger, Physics and Chemistry, vol. 1, p. 203, 1884. 

 H. Great Salt Lake. Analyses by J. E. Talmage, Science, 14, 445 (1889). 



I. Caspian Sea. Mean of five analyses by C. Schimdt, Bull. Acad. St. Petersburg, 24, 177 (1878). 

 J. Dead Sea. Analysis by F. A. Genth, Ann., 110, 240 (1859). 



(4) Natural bitterns, of which the water of the Dead Sea is the only representative 

 given in the table. In waters of this type prolonged evaporation has brought about a 

 concentration of the bromides and the soluble potassium and magnesium salts, while the 

 more insoluble compounds, as sodium chloride and the carbonates and sulphates of cal- 

 cium, have for the most part crystallized out. 



If the assumption is correct that the salts leached out from the bottom of the Salton 

 Sea represent approximately the composition of the original lake, then this must have 

 resembled in a striking way the composition of the water of Great Salt Lake. 



The salts taken up by the Salton Sea likewise resemble in a general way the composi- 

 tion of the salts in the ocean. The higher sodium, the lower potassium and bromine, and 

 the probable absence, or low proportion, of carbonates in the former are the principal 

 points of difference. The concentration, however, of the former lake which deposited the 

 salts taken up by the present lake no doubt differed much from that of the ocean, for at 

 its maximum volume the total salinity of the present lake was only about one-ninth that of 

 sea-water; consequently if it be assumed that the salts taken up by the Salton Sea originally 



