1905.] Function of Silica in the Nutrition of Cereals. ±69 

 80%, 1 1 1 1 1 



duly 4 11 18 25 Augi 6 



Fig. 9. — Nitrogen. Percentage of whole content present in Grain. Plots with Potash.] 



As regards the phosphoric acid, the proportion of phosphoric acid in the 

 dry matter of the grain is increased by the use of phosphatic manure, as it 

 is also by the use of silica, especially where no phosphatic manuring takes- 

 place. The removal of the phosphoric acid to the grain is naturally more 

 complete in the cases of phosphoric acid starvation ; and when silica with- 

 out phosphoric acid has been supplied, almost the whole of the extra 



July 4 



Fig. 10.— Phosphoric Acid. 



25 



Aug.! 



Percentage of whole content present in Grain, 

 without Potash. 



Plots ■■ 



