204 



THE BOTANICAL MAGAZINE. 



[Vol. XXVII. No. 322. 



Solutions used 



Length 

 of leaf 



Li ogth 



of root 



Number 

 of roots 



1/10 N. MgSO 4 S0cc. 



mm. 



50 



23 m " 



1 



1/10 N. MgS 4 25 cc. + 1/10 X. CuCl, 5cc. 



135 



55 



4 



1/10 N. MgS0 4 20cc. + l/10 N. CaCh 10 cc. 



135 



50 



6 



1/10 N. J/gtfQ, lScc+1/10 N. r'aCV., 15 cc. 



120 



45 



6 



1/10 N. %S0 4 lOcc + 1/10 N. CWl 2 20 co. 



85 



25 



4 



1/10 N. %£0 4 5cc. + l/10 N. CaC7 2 25cc. 



80 



18 



3 



L/10 N. CaC7 2 30 cc. 



35 



8 



1 



From the results obtained in all of these experiments, we 

 may summarize as follows : 



1. The salts under examination, used separately, are very 

 poisonous in 1/10 normal concentration upon the growth 

 of rice plant, but when the two salts are mixed with 

 each other in a suitable proportion, the toxic effect of each 

 salt more or less completely disappears. This result is 

 of great importance in alkali soil investigations. 



2. The antagonistic action of salts is due to that of the 

 ions formed by the dissociation of the salt. 



3. In general, divalent cations are markedly antagonize 

 monovalent, but on the contrary, monovalent cations 

 do not strongly antagonize divalent cations. 



4. Among the divalent cations, calcium shows a more 

 marked antagonism than magnesium. 



5. The antagonism between CI' and SO", though it is 

 small in comparison with that between cations, is also 

 present in no slight degree. 



CHEMICAL LABORATORY, COLLEGE OE AGRICULTURE, 



TOHOKU IMPERIAL UNIVERSITY, SAPPORO, JAPAN. 



JUNE 1913. 



