240 D. T. MacDougal—TTie Salton Sea. 



lake and its problems. The rapid inflow of silt-laden river 

 water first covered the saline beds at the bottom of the Sink, 

 dissolving the salts in the surface layers and then leaching out 

 the contents of the alluvium beneath. This process followed 

 so slowly that samples taken at a depth of 60 feet in February, 

 1907, nearly fourteen months after the salt deposits were flooded, 

 contained 352 parts in a hundred thousand of dissolved mate- 

 rial as compared with 330 parts at the surface of the lake. 



As might be expected, those samples were found most salty 

 which were taken from shallow regions overlying saline flats, 

 while samples taken from the surface in deep parts of the lake 

 contained less amount of salts. Thus, on June 10, 1906, when 

 the greatest depth of the lake was about 35 feet, a sample taken 

 1-J- miles from shore near Mecca was found to contain 401*6 

 parts of total solids in 100,000 ; a second sample, taken at the 

 same time from a point 100 feet from shore, contained 697*1 

 parts of solids ; and a third sample, collected a short time 

 before within a few feet of the shore near Travertine Point, 

 showed a salt content of 1152*8 parts. The water at this point 

 was very shallow and covered a saline deposit. 



Within the next few months a marked increase in uniformity 

 took place, as shown by the analysis of two samples collected 

 on October 11. One of these taken from shallow water near 

 the shore contained 363*2 parts of solids in 100,000, while a 

 half-mile from shore a sample yielded 359*6 parts. 



The dates on which the samples w T ere collected and the re- 

 sults of the eight yearly analyses are given in the following 

 table. Instead of aiming to give a statement of the constit- 

 uents which occur in solution, the analysis of each sample was 

 made to represent rather the composition of the anhydrous 

 inorganic matter which is left when the water is evaporated to 

 dryness. Those elements, like silicon, iron, and aluminium, 

 which occur in the residue in the form of their oxides, are rep- 

 resented as such, but all other coustituents which occur in 

 combination as salts are expressed in the ionic form. In this 

 way the necessity for making assumptions regarding the way 

 in which the constituents are combined is avoided. 



With the exception of the first year period, the yearly per- 

 centages of increase of the constituents are seen to increase 

 progressively. This result is to be expected, for as the volume 

 of the lake becomes smaller an equal loss of water by evapora- 

 tion will produce a greater increase in concentration of the 

 constituents. 



The difference, however, in the fall of the surface of the 

 lake between the first and second year periods is not great 

 enough to correspond to the difference found between the total 

 constituents for the same periods, and it may therefore be con- 



