Sept. lo, 191 7 



Formation of "Black Alkali'' 



577 



Table XXXIX. — Solubility of organic matter in sodium-carbonate solutions 



Table XL. — Solubility of organic matter in sodium bicarbonate 



Solution No. 



Parts per 

 million 



after sub- 

 tracting No. 



I (control) 

 from others. 



2 

 3 

 4 



5 

 6 



6 

 20 

 36 

 46 



As the soils contain some bicarbonates, more was recovered in some 

 cases than vv^as added. Sodium bicarbonate seemed to exert little effect 

 upon the organic matter of the soil. 



EFFECT OF SODIUM SALTS UPON THE SOLUBILITY OF CALCIUM CAR- 

 BONATE IN SOILS 



In treating a soil with a sodium-chlorid solution, with and without 

 calcium carbonate, and analyzing it for lime in the usual way, a striking 

 phenomenon is to be noticed. In Table XLI is shown the total amount 

 of water-soluble lime calculated to calcium carbonate obtained by two 

 different methods of analysis. In the first method the total lime was 

 precipitated as calcium oxalate and weighed as calcium oxid. In the 

 second method the bicarbonates in the solution were titrated with stand- 

 ard acid and the titrations calculated to calcium carbonate. 



