88 CHARLES B. LIPMAN 



cess of magnesia over lime was found to retard growth, small 

 leaves being obtained, though no symptoms of dwarfing disease 

 were noted. 



In the third paper, ^ Aso describes a specific study of the sub- 

 ject of the lime-magnesia ratio as affecting rice. This work was 

 carried out in pot experiments from which it is claimed that the 

 ''lime factor" of Loew, so far as rice is concerned, agrees with 

 that of other Gramineae, or in other words, is between 1 and 2. 

 It is further noted that rice shows a relatively high resistance to 

 an excess of magnesium carbonate and that the latter does not 

 depress the yield of rice so much as does an excess of lime. Maxi- 

 mum jdelds, according to this investigation, depend to a very 

 great degree, on the maintenance of the proper ratio of 1 to 1. 



About the same time other Japanese investigators busied them- 

 selves with the subject of the lime-magnesia ratio. These in- 

 vestigations were, evidently, all inspired by the work of Loew him- 

 self, in Japan. The first of these which may be reviewed here is 

 that of Daikuhara,^ who grew beans in pots adding lime and 

 magnesia in varying quantities to the soil. As a result of these 

 experiments he claims to have found that in the growth of the 

 bean prior to the fruiting stage, a ratio of 2 of lime to 1 of mag- 

 nesia gives the best results. The criteria employed were vigor 

 of plant, height of stems and size of leaves. 



Nakamura^ carried out pot experiments with barley. He used 

 a natural soil which contained seventeen times as much lime as 

 magnesia, both being determined by the strong hydrochloric acid 

 digestion method. He added to this soil varying quantities of 

 magnesium sulphate from one-twenty-fifth to one-fifth of the 

 amount necessary to make the quantity of magnesia in the soil 

 equal to that of the lime. He found that the amount of mag- 

 nesia which was equivalent to 88.82 grams per pot, as against 

 170 grams of lime, or a ratio of 2 of lime to 1 of magnesia, gave 

 the best results. 



In 1905 to 1906 another series of investigations was published 



« Jour. Col. Agr. Tokyo, Japan, vol. 6, p. 97, 1904. 

 ' Bui. Col. Agr. Tokyo, Japan, vol. 5, p. 501, 1903. 

 * Landw. Jahrb., vol. 34, p. 141. 



