32 



As the different crops were grown at various seasons of different 

 years, as well as to different stages of maturity, one is hardly justified 

 in comparing the different analyses to see how the ash composition 

 of rice straw varies with its development. It appears, liowever, 

 that there is a constant decrease in the percentage of iron as the plant 

 approaches full maturity. 



The relative composition of the different crops from tlie four ])lats 

 is shown in Table XXV. 



Table XXV. — lielative ash composition of rice straw from the different plats. 

 CROP G (25 DAYS' GROWTH). 



CROP B (84 DAYS' GROWTH). 



CROPS C AND D (102 DAYS' GROWTH). 



CROPS E AND F (129 DAYS' GROWTH). 



The youngest crop, G, seems to show more disturbance in its ash 

 composition than the other crops. In tliis crop the most marked 

 effect of the carbonate of lime upon the plant ash has been in greatly 

 increasing the amount of lime and in diminishing the amount of iron, 

 total ash, and silica. The same, although less marked, variations 

 occur in crop B as in crop G. Crops C to F on the Ume plats also 

 show in their ash composition a great increase in Ume and a diminu- 

 tion in total ash and silica, but no diminution in iron. 



