Antitoxic Action of Certain Bases 133 



was able to determine the influence of various solutions on different roots 

 of the same plant. The results substantiate the view that Ca(N03)2 

 mollifies the deleterious properties of Mg(N03)2 and MgS04. Further- 

 more, in solutions that contain no calcium, only slight elongation of the 

 roots of wheat and oats takes place. 



From experiments with flax grown in pots of soil in which the ratios 



— — — were 1:1 and 2:1, respectively, Namikawa (1906) concluded that the 

 MgO ^^Q 



most advantageous ratio of — r^- for flax is 1:1. The yield is 21 per cent 



MgO 



lower in soil cultures that have the proportions of lime to magnesia 2:1 



and 3:1. Similar results were obtained with spinach grown in sand 



cultures. 



Maki and Tanaka (1906) grew barley to maturity in loamy and sandy 



CaO 



soil cultures. Sufficient slaked lime was added to make the ratio 



MgO 



about 3:1. This relation caused a decrease in the yield, or the soil was 



overlimed. When a sufficient quantity of magnesium sulfate was applied 



to make the ratio 1:1 in the overlimed soil, the harvest was almost as great 



as in the untreated soil. In case of the sandy soil the crop was greater 



than the control cultures. 



Yokoyama (1908) observed that when oats are grown in pots containing 

 sandy soil poor in lime and magnesia the addition of lime is injurious, due 

 to the unbalanced ratio of lime to magnesia. Furthermore, such soils 

 should be treated with dolomitic limestone in order to correct such unbal- 

 anced conditions. 



In sand cultures Aso (1909) ascertained that the lime factor for oats is 1, 

 for adzuki beans (Phaseolus mungo) about 2, for rice 1, and for Italian 

 millet between .5 and 1. His conclusions are: 



"1. Certain favorable ratio of lime to magnesia for plant-growth exists 

 even in sandculture. 



" 2. Absolute excess of lime or magnesia provided it be kept within 

 certain limits, has no retarding effect on the development of the plants, 

 the ratio between these bases being the chief factor for plant growth." 



Gile (1913), as a result of his work, states: '' The toxicity of an excess 

 of lime or magnesia is not due simply to an unfavorable ratio between 

 these two salts alone, but to an unfavorable proportion between the salt 

 which is in excess and all the other salts present." 



