412 
Journal of Agricuimral Research 
Vol. VII, No. 9 
tion in the potash and phosphoric-acid content is again shown as the 
sodium-carbonate concentration increases. In this series also there is a 
decided reduction in the total nitrogen content with increasing concentra¬ 
tion of the sodium carbonate. 
Reference to Table III will show that the weight of the seedlings de¬ 
creased markedly as the concentration of the sodium carbonate in¬ 
creased. It is consequently of interest to express the nitrogen, potash, 
Fig. 5. —Graphs of the mean values of the first and second series showing the effect of sodium carbonate 
on the nitrogen, potash, and phosphoric-acid content expressed in percentage of the dry weight of wheat 
seedlings. 
and phosphoric-acid content of the seedling plants in percentage of 
their dry weight. The results computed on this basis will be found in 
the last three columns of the table. The mean values for both series of 
determinations are plotted in figure 5. It will be seen that the percentage 
of nitrogen does not show any consistent change as the concentration of 
the sodium carbonate increases. The percentages of potash and phos¬ 
phoric acid, on the other hand, decrease markedly with increasing con¬ 
centration of the sodium carbonate. 
