Antitoxic Action of Certain Bases 131 



CaO 

 limestone and magnesite differed so much that the ratio—- — was changed 



MgO ^ 



from 1/1 to 100/1." This last point, however, does not appear to the 

 writer to be established through sufficient experiments. 



Daikuhara (1905a) observed that "the yield of naked barley was not 

 essentially altered when the amounts of these bases [calcium and mag- 

 nesium] were rendered equal by adding CaCOa or MgCOs," when the 

 difference did not exceed .5 per cent. On well-manured soils in which the 

 ratio was .34: 1 the harvest was doubled by producing a ratio of 1:1. 



The data obtained by the same author (1905 b) from sand cultures show 

 that " in the presence of lime as carbonate the necessary amount of mag- 

 nesia when applied as crystallized sulphate for paddy rice in sand culture 

 is so small that the best ratio CaO: MgO becomes 30: 1, while in the form 

 of natural carbonates the best ratio would be 1:1." 



The results given by Nakamura (1905) with barley grown in pots of soil 

 " show decidedly that the addition of a certain quantity of magnesia acts 

 very beneficially upon the growth of the plant when the soil contains a large 

 excess of lime over magnesia and furnish at the same time a further proof 

 of the inference that ' a maximum yield depends — other things being 

 equal — also upon a certain ratio of lime to magnesia which enters into 

 the plant.' " 



Wheeler and Hartwell (1903) found that in pot cultures CaCb and NH4CI 

 exert '' a marked poisonous action upon certain plants, when applied to a 

 soil which was already somewhat acid. Magnesium chlorid was not found 

 to be poisonous under conditions where great injury from calcium chlorid 

 and ammonium chlorid resulted. 



" Calcium carbonate and caustic magnesia used singly, also a mixture 

 of basic slag meal with the carbonates of potash and magnesia, were found 

 to prevent or overcome the ill effect produced by applications of either 

 calcium chloric! or ammonium chlorid." 



Bernardini and Siniscalchi (1908) grew lupine in pot cultures and con- 

 cluded that " the injurious action of an excess of lime and the poisonous 

 action of an excess of magnesia in the soil is not due to the absolute quan- 

 tity of calcium and magnesium ions absorbed by the plant, but to the 

 ratio in which they are absorbed." 



Konovalov's results (1907) with wheat, lupine, and oats grown in water 

 and sand cultures do not confirm Loew's view that " there is a definite 



