K. MIFAKK—INWjOENOE of the SALT etc. 



269 



time to time so as to keep the solutions always in their initial 

 dilutions. On March 24th, the difference in development in the 

 respective cultures was very striking ; the following determina- 

 tion was made : 



Solutions used 



Length 

 of leaf 



Length 

 of root 



Number 

 of roots 



1/10 N. KCl 30 cc. 



mm. 



40 



mm 



17 



3 



1/10 N. KCl 25 cc. + 1/10 N. MgCl, Dec. 



60 



16 



4 



1/10 N. KCl 20cc.+ l/10 N. MgCh 10 cc. 



58 



15 



6 



1/10 N. KCl 15cc.+ l/10 N. MgCL 15 cc. 



55 



15 



7 



1/10 N. KCl lOcc+1/10 N. MgCl 2 20 cc. 



55 



15 



5 



1/10 N. KCl 5cc. + l/10 N. MgCh 25 cc. 



56 



21 



4 



1/10 1ST. MgCk 30 cc. 



43 



23 



3 



Distilled water 30 cc. 



63 



47 



11 



In pure magnesium chloride solution the seedlings had 

 grown only 18 mm. in 18 days; in potassium chloride solution, 

 only 15 mm. ; while in distilled water the length of leaf had 

 attained to 63 mm. Therefore, it is evident that potassium 

 chloride and magnesium chloride have a poisonous action upon 

 the growth of rice seedlings. 



This poisonous effect largely disappears when we mix the 

 two salts (MgCl 2 -KCl) in proper proportions. In the mixture 

 1/10 N. KCl 25 cc— 1/10 N. MgCl 2 5 cc, the growth of the 

 seedlings was most vigorous and their height had reached to 

 60 mm. Therefore, it is evident that in the mixture of mag- 

 nesium and potassium chloride in favorable proportion, the 

 seedlings grow about twice as much as in pure salts solution. 



It will be noticed that decreasing the proportion of potas- 

 sium or increasing the amount of magnesium beyond the opti- 

 mum proportion causes unfavorable conditions for the growth 

 of the seedlings. Accordingly, a small amount of magnesium 

 retards the toxic effect of potassium, and on the other hand, 

 potassium retards the injurious action of magnesium with large 

 amount. 



