310 Soda- Salts in Agriculture. 



Experiment No. 6. — On a Sterile Ferruginous Saudi/ Soil. 



The last experiment with chloride of sodium was tried upon a 

 soil distinguished from the others by its sterile character ; it 

 contained an excessive proportion of oxide of iron, much quartz — 

 sand, little clay, and mere traces of lime. 



The analysis yielded the following results : — 



Moisture l-IO 



*()ruanic matter o'lVJ 



Oxides of iron and alununa 12'1(! 



Carbonate of lime '15 



Alkalies and magnesia '40 



Insoluble siliceous matter 82*41 



Sulphuric and phosphoric acid traces 



100-00 



' ^Containing nitrogen .. .. '21 



Equal to ammonia '25 



The salt-solution, containing' 4()'320 grains of pure chloride of 

 sodium, left in contact with the soil for four days, gave the 

 following results : — 



Organic matter 2'180 



Soluble silica "100 



Oxides ot'iron and alumina '122 



Chloride of sodiimi aC"222 



Chloride of potassium "818 



Chloride of magnesium '304 



Chloride of calcium "608 



Sulphate of lime 1"070 



Phosphoric acid '040 



Chloride of 

 Sodium. 



41-524 



Before the experiment, 4 dcci-gallons of salt-) aq-qou — oi-^rr 



solution contained f ~ — - 



After contact with 3500 grains of soil .. 36-222 = 19-193 



4-098 2-173 



1000 grains of this soil consequently absorbed 0-62 of a grain of 

 soda. 



A separate deci-gallon, on evaporation, left 10-33 grains of 

 residue dried at 3()0^ Fahr., which gives 41-320 grains per four 

 deci-gallons, a result which agrees as closely as can l^e expected 

 with the results obtained in the above detailed analysis. 



If we calculate the amount of chlorine in the four chlorides 

 mentioned in the analvsis of the liquid after contact with soil, we 

 find :— 



