586 



Journal of Agricultural Research 



Vol. X. No. II 



Table XLVIII. — Saponification of ethyl acetate by sodium carbonate in the presence of 



sodium sulphate 



These two tables clearly show to what degree the presence of sodium 

 chlorid and sodium sulphate holds back the hydrolysis of sodium carbo- 

 nate. Under field conditions we might expect black alkali to be more 



Fig. as. — Graphs showing the saponification of ethyl acetate by sodium carbonate in the presence of sodium 



chlorid. 



caustic when acting alone than when in the presence of either sodium 

 chlorid or sodium sulphate. 



In judging the amount of organic matter by the color of the solution in 

 this and in preceding experiments the writer realizes that the method is 

 far from satisfactory and that the data obtained do not represent the 

 absolute amount of organic matter in solution. But the error in the 

 determination would quite likely remain fairly constant in the different 

 experiments, and, therefore, comparable results could be reasonably 

 expected. This was all that was hoped for. 



EFFECT OF LIME H.^RDPAN UPON FORMATION OF BLACK ALKALI 



It is a well-known fact that a hardpan frequently accompanies black 

 alkali. It has been commonly supposed that the black alkali is responsi- 

 ble for the hardpan, whereas in many cases the opposite may be true. 

 If the hardpan is simply a puddled condition of the soil, the puddling 

 might readily be brought about by the black alkali. In the case of the 

 calcareous hardpan, with a sodium salt present, even if the top soil is 

 not calcareous, black alkali might readily be produced in the following 



