On the Influence of Different Ratios of Lime and 

 Magnesia upon the Development of Plants, 



BY 



K. Aso. 



The physiological functions of magnesia and lime have been 

 discussed repeatedly by O. Loetu, 1 whose theory explains on the 

 one hand why a certain amount of magnesia in the soil can act 

 injuriously on the crops, and on the other why the liming 

 counteracts this injurious effect ; and also further why a certain 

 excess of lime has no longer any beneficial effect, but even 

 retards development and decreases the yield. In the following 

 lines I describe some further experiments which illustrate the 

 unfavorable effect of a certain excess of magnesia as well as of 

 lime, and show that for certain crops there exists a well defined 

 ratio between these two bases that is more favorable to growth 

 than any other ratio. I will at first describe some experiments 

 made with calcium and magnesium nitrate alone, in the absence 

 of other nutrients. 



I. Action of Magnesium and Calcium Nitrate. 



Seeds of bailey and wheat were soaked for three days in 

 solutions of 0.5% of calcium and magnesium nitrate respectively, 

 and after germination two of each kind of the young shoots of 

 6-7 cm. length were placed in \% solutions of calcium nitrate 

 and \% magnesium nitrate. Two other shoots of each kind 

 were kept in distilled water for control (Dec. 21.). The tem- 

 perature of the room ranged during the following eighteen days 

 from 7 0 to 14 0 . 



1 Flora, 1892 ; Landw. Versuchs-Stationen, vol. 41. Bull. No. 18. U. S. Depart- 

 ment of Agriculture, Division of Vegetable 1'hysiology and Pathology, Washington, 1899. 

 PP-35; 4 2 ; 47; 6o - I)ie Chemische Energie der Iebenden Zellen, Mttnchen 1890. 

 Chapt. IV. 



