50 REPORTS ON INVESTIGATIONS AND PROJECTS. 



The salt-content of the water was over 0.25 per cent at the maximum 

 level in 1906. This has now increased to 0.72 per cent. The investigation of 

 various problems connected with the making and desiccation of the lake has 

 now proceeded far enough to make some interpretation and correlation of 

 results profitable and possible. The more important features will therefore 

 be discussed in a manuscript now in course of preparation. 



Jlie Composition of the Water of Salton Lake, by Dr. IV. H. Ross. 



In accordance with the practice of previous years, a large sample of water 



was on June 3 taken from near the surface over the deepest part of the lake, 



under the personal supervision of Dr. Ross. The preliminary data from the 



analysis of this sample may be given as follows : Parts per 



100,000. 



Total solids dried at 110°,. plus water of occlusion and hydration 718.00 



Chlorine, CI '. 339-00 



Nitrates, NO3 none 



Nitrates, NO2 none 



Free, CO2 o. 72 



Bicarbonic, HCO3 I7- 14 



Carbonic, COs (in evaporated residue of the water) 5.78 



Oxygen consumed 0.63 



The total solids plus the water of occlusion and hydration have increased 

 by 18.9 per cent over that found for last year, while the chlorine has in- 

 creased by 20.8 per cent ; the corresponding percentage increases of last year 

 were 16.2 and 16.6. The bicarbonates in the water show a decrease, as noted 

 in the report of the previous year. A number of samples were taken from 

 the bottom of the lake and from localities widely separated from the surface, 

 and the analysis of these samples shows that the whole body of water is re- 

 markably uniform. This implies that the leaching from the beds covered by 

 the water has removed the salts from the upper layers, so that diffusion goes 

 on very slowly, and that the increasing salt-content of the lake is due almost 

 wholly to the inwash of surface deposits around the lake and to the losses 

 by evaporation. Although, as noted in a previous paragraph, a very con- 

 siderable amount of fresh water is brought into the lake through the Alamo 

 and New rivers, as well as from artesian wells, yet the wind action keeps the 

 body of the water in the lake constantly stirred. 



The Behavior of Unicellular Organisms in Condensing Brines, by 

 Prof. G. J. Peirce. 



The study of the micro-organisms in the brines of the salt works on the 

 shore of the San Francisco Bay has been continued by weekly collections 

 and by pure cultures of some of these organisms. The great range of con- 

 centration, from rain-diluted sea-water in winter to a brine containing 30 

 grams of solid matter in 100 c.c. in late summer, demands an extraordinary 

 adjustment of the organisms to the changing environment. The organisms 

 respond to the environmental changes by differences in the modes of repro- 

 duction as well as in vegetative ways. A quantitative chemical analysis of 



