302 



CHARLES B. LIPMAN 



TABLE VI.A 

 NaCl versus NaaCOs 



TABLE VIb 

 Na2C03 versus NaCl 



Taking up a consideration of the most striking features of 

 each of the tables above given, we find in Table IVa in which a 

 uniformly toxic quantity of NaCl (0.2%) was employed and 

 varying quantities of Na2S04 the following interesting facts. 

 When NaCl is used alone at the concentration indicated con- 

 siderably less than 50% of the amount of nitrates is produced 

 that results normally from the activities of the same flora in the 

 same soil that is free from salts. Yet any quantity of Na2S04 

 from 0.05% to 0.2%, inclusive may be added to 0.2% NaCl, 

 in the latter case doubling the alkali content of the soil, and 

 nitrification is not only not depressed further but is much im- 

 proved over that of the normal soil. Even when 0.3% Na2S04 

 is added to 0.2% NaCl, thus making a total alkali content of 



