Soda-Salts in Agriculture. 309 



weight. The organic matter was then destroyed by heat aiad the 

 residue analysed in the usual manner. 



Calculated for four deci-gallons, the salt-solution after con- 

 tact with soil contained : — 



Organic matter 2*520 



Soluble silica -100 



Oxides of iron and alumina '080 



Sulphate of lime 1-428 



Carbonate of lime 2'172 



Chloride of sodium 33'642 



Chloride of potassium 'SSS 



Chloride of magnesium '460 



Chloride of calcium 5'758 



Phosphoric acid '038 



46-736 



One deci-gallon evaporated to dryness gave 11 -625 grains of 

 residue dried at 300°; this gives 46*500 grains for the whole 

 salt-solution, and agrees very well with the sum-total of the 

 constituents found in the detailed analysis. 



The chlorine, I may observe, was determined in a separate 

 portion, and not in the residue left on evaporation. 



Calculated for four deci-gallons, 



The amount of chlorine found was 24-696 



Chlorine in the 40-32 of chloride of sodium contained) 04.4.^7 

 in 4 deci-gallons of solution J 



Difference -229 



No chlorine whatever it will be seen was absorbed, and the 

 amounts found in the solution, before and after the experiment, 

 were almost identical. 



The chlorine was thus distributed amongst the different basic 

 substances dissolved by the salt-solution from the soil : — 



Chlorine in combination with sodium .. .. 20*413 



Chlorine in combination with potassium . . . . *256 



Chlorine in combination with magnesium .. .. "344 



Chlorine in combination with calcium 3*683 



Total chlorine found 24-696 



Absorption of soda by the mai'ly soil took place as follows : — 



Chloride of 

 Sodium. 



Soda. 



Before contact with 3500 grains of soil, 4 deci-) aq-s^O — '^l-SCC ' 



gallons of salt-solution contained . . . . J "" ~ "" 



After contact 33*642 = 17-878 



Difference 6*678 = 3*488 



1000 grains of soil accordingly absorbed 0*996 of a grain of soda, 

 or very nearly 1 per mille. 



