I TO S. Uchiyaina. 



3. P>en a certain excess of gypsum produced the most favorable result. 

 The different availability of calcium carbonate and sulphate^^ partly 

 accounts for the fact that here the ratio CaO : MgO = 2 : i'-' did not 

 depress the harvest. 



4. In the presence of sodium nitrate, the phosphoric acid of bone 

 • phosphate is not so easily available as in the presence of ammonium 



sulphate (compare F with the other pots) in accordance with the 

 results of other investigators. 



5. In the pot E with 0.4 g. potassium carbonate, the harvest was 

 poorest ; but in how far this was due to the substitution of am- 

 monium nitrate by sodium nitrate and in how far to the increased 

 alkaline reaction caused by potassium carbonate, could not directly be 

 decided. 



6. Since the plants grown with gypsum were of a deeper green than 

 those grown with carbonates, it seems that the chlorophyll produc- 

 tion was also somewhat interfered with in the latter cases. Further, 

 investigations on this point however are contemplated. 



The above observations with sand-culture rendered it desirable to 

 compare also in soil-culture the effect of potassium carbonate and also of 

 wood ash with that of potassium sulphate, when bone dust serves as a 

 phosphatic manure. 



Soil-culture : An alluvial sandy soil poor in humus was selected for 

 this purpose, since the presence of much humus would have led probably to 

 the neutralization of potassium carbonate. 



Experiment with Barley. 



The experiment was carried out in two parallel series. Eight 

 zinc pots received 10 kilo, air-dry soil. On Nov. 4, 1904, 6 g. sodium 



i). O. Loew and K. Aso : "On Different Degrees of Availability of Plant Nutrients," The 

 Bulletin, Col. of Agric, Tokyo, Vol. VI., No. 4, p. 335. 



2). One plant showed here an average weight of 7 g. in the air-dry state, which is certainly a 

 good result for san ^'culture. 



