CHEMICAL COMPOSITION OF THE WATER OF 8ALTON SEA. 



39 



hours. The amount of potassium permanganate left undecomposed at the end of this 

 time was determined by adding a few drops of a 10 per cent potassium-iodide solution and 

 titrating with standard sodium thiosulphate, using starch paste as indicator. From the 

 amount of permanganate which was decomposed by the water its oxygen-consuming power 

 could be calculated, knowing that 1 c.c. of N/50 potassium-permanganate solution contains 



50X1000 ^^^^ °^ available oxygen. 



TOTAL SOLIDS. 

 The residue, obtained by evaporating 50 c.c. of the water in a platinum dish on the 

 water bath and then drjdng to constant weight at 110° C, contained, besides the dissolved 

 constituents, water occluded by crystals of salt and hydration water contained in the basic 

 magnesium compounds. The amount of water thus contained in the residue was deter- 

 mined by evaporating a separate sample of 500 c.c. in the same way as before, and noting 

 the difference obtained between the weight of the residue dried at 110° C. and when ignited 

 gently below redness. The same result was found for the concentration of the total solids 

 when 500 c.c. were evaporated as when a smaller sample was taken. 



ANALYTICAL RESULTS. 



The dates on which the samples were collected and the results of the five yearly 

 analyses are given in table 6. Instead of aiming to give a statement of the constituents 

 which occur in solution, the analysis of each sample was made to represent rather the com- 



Table 6. — Five complete analyses of the Salion, Sea xoater. 



Total solids (dried at 110° C.) plus 



water of occlusion and hydration. . 



Water of occlusion and hydration . . . 



Sodium, Na 



Potassium, K 



Lithium, Li 



Calcium, Ca 



Magnesium, Mg 



Alumina, AI3O1 



Ferric oxide, FeiOi 



Silica, SiOj 



Manganese, Mn 



Lead, Pb 



Copper, Cu 



Chlorine, CI 



Bromine, Br 



Iodine, I 



Sulphate radicle, SO« 



Carbonate radicle, COt 



Arsenate radicle, AsO* 



Phosphate radicle, PC* 



Nitrate radicle, NOi 



Nitrite radicle, NOi 



Oxygen consumed 



Borate radicle, BGi 



Total constituents 354.93 



Farts per 100,000. 



June 3, 

 1907. 



364.8 



111.05 

 2.30 

 trace 

 9.96 

 6.43 

 0.056 

 0.007 

 0.92 

 none 

 none 



May 25, 



1908. 



169.75 



47.60 

 6.58 



0.009 

 0.18 

 none 

 0.093 



437.20 



134.26 

 2.78 

 0.013 

 11.87 

 7.63 

 0.065 

 0.009 

 0.93 

 none 

 none 



204.05 



56.74 

 7.66 



"o.oii 



0.20 

 trace 



0.059 

 trace 



June 8, May 22, 

 1909. 1910. 



519.40 

 17.50 

 160.33 

 3.24 

 0.017 

 12.70 

 8.96 

 0.117 

 0.014 

 1.04 

 none 

 none 

 trace 

 240.90 



603.80 

 22.56 

 189.28 

 3.53 

 0.021 

 13.67 

 9.84 

 0.075 

 I 0.011 

 I 1.01 

 I none 

 none 

 trace 

 280.93 



426.27 



65.87 

 7.34 



6.61 



none 

 0.0006 

 0.068 



trace 



76.36 

 6.38 



'6.013 



none 



none 



0.045 



trace 



600.61 581.17 



Jane 3, 

 1911. 



718.00 



20.84 



227.81 



3.81 



0.025 



16.62 



11.68 



0.168 



0.051 



1.19 



none 



none 



trace 



339.42 



trace 



none 



91.67 



6.78 



none 



trace 



none 



none 



0.063 



trace 



697.28 



position of the anhydrous inorganic matter which is left when the water is evaporated to 

 dryness. Those elements like silicon, iron, and aluminium, which occm- in the residue in 

 the form of their oxides, are represented as such, but all other constituents 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. On 

 evaporating the water the alkaline-earth bicarbonates in solution are decomposed, yielding 



