Antitoxic Action of Certain Bases 



157 



Magnesium and strontium. — It has been seen that magnesium and 

 strontium are toxic at comparatively weak concentrations. However, 

 when these bases are combined in the proper proportions and concentra- 

 tions this toxicity is mutually counteracted. 



Inasmuch as Canada field pea seedlings elongate but little in the absence 

 of calcium, a trace of this compound — N/1000 CaCl2 — was added to 

 each of the cultures in the experiments noted below. With the increase in 

 growth obtained by the addition of calcium the antidoting action of the 

 bases magnesium and strontium is more obvious. 



TABLE 25. 



Experiment with Canada Field Pea. 

 FOR Ten Plants 



Duration, Thirty Days. Data 



Composition of solution 

 (N/1000 CaCU as the solvent) 



N/200 MgCl2+N/100 SrCl2. 

 N/200 MgC1.2+N/o00 SrCh. 

 N/200 MgCl2+N/ 1,000 SrCl 

 N/500 MgCl2+N/500 SrCh. 

 N/1,000 MgCl2+N/500 SrCl 



N/100 SrC]2 



N/500 SrCl2 



N/200 MgCU 



N/1,000 CaCl. 



Green 



weight 

 of tops 

 (grams) 



Green 

 weight 

 of roots 

 (grams) 



Total 



green 



weight 



(grams) 



4.40 

 5.86 

 7.45 

 6.70 

 6.26 

 4.20 

 5.65 

 3.59 

 8.36 



Average 

 length 

 of tops 

 (centi- 

 meters) 



Average 

 length* 



of roots 

 (centi- 

 meters) 



9 



9 



10 



9 



7 



10 



The writer's experiments demonstrate a definite antagonistic action 

 between magnesium and strontium. The toxicity is not entirely over- 

 come, since the growth in the mixed solutions is not so extensive as in the 

 control, N/1000 CaClo. Mutual antagonism exists when these bases are 

 present in diverse ratios; for example, it occurs in solutions made up as 

 follows: N/200 MgCls+N/lOO SrCla and N/200 MgCl.+N/lOOO SrClo. 

 The greater growth occurs in the latter solution. 



Sodium and potassium 

 Osterhout (1909), in working with wheat, observed that mutual antag- 

 onism exists between sodium and potassium. The data presented below 

 are taken from one of his tables: 



