Antitoxic Action of Certain Bases 



161 



injurious action. When N/10 CaCl2 is present in solution with either 

 N/100, N/500, or N/1000 BaCla, no injury results. 



Calcium and sodium 



The results obtained from further studies of the relations between cal- 

 cium and sodium are similar to those just discussed. Older seedlings are 

 more tolerant of sodium ions than are younger ones. Seedlings taken 

 from the germinating pan and placed directly in N/100 NaCl soon perish. 

 On the other hand, those that are grown for ten days in a full nutrient 

 solution withstand any solutions weaker than N/20. Calcium chlorid of 

 N/10 concentration prevents injury from N/20 NaCl. The data obtained 

 appear in Table 29: 



TABLE 29. 



Experiment with Pea Seedlings. Duration, Thirty Days. 

 Ten Plants 



Data for 



Composition of solution 



Green 

 weight 

 of tops 

 (grams) 



Green weight 

 of roots 

 (grams) 



Average 

 length 

 of tops 

 (centi- 

 meters) 



Average 

 length 

 of roots 

 (centi- 

 meters) 



N/10 CaCL +N/20 NaCl . 

 N/10 CaCU -FN/100 NaCl 

 N/10 CaCU +N/500 NaCl 

 N/10 NaCl 



N/20 NaCl 



N/100 NaCl 



N/500 NaCl 



N/10CaCl2 



Distilled water 



Nutrient solution 



6.85 



7.14 



• 8.18 



No growth 



Dead 



5.00 

 4.60 

 7.90 

 5.30 

 12.40 



5.65 

 6.37 

 7.37 



Weight not 

 taken 



Weight not 

 taken 

 4.00 

 4.25 

 6.00 

 3.45 

 8.25 



15.0 

 13.0 

 15.0 



Slight growth 

 9.5 

 10.0 

 17.0 

 10.0 

 15.0 



9.0 

 8.0 

 8.0 



7.5 

 8.0 

 7.0 

 6.0 

 10.0 



Calcium and strontium 



Older seedlings are also more resistant to strontium ions than are younger 

 seedlings. Calcium is effective in preventing this deleterious action, 

 since no injury results in solutions composed of N/100 CaCl2+N/50 

 SrCl2. The essential data are set forth in the following table: 



