57 



Table XXIII. "Jodidi numbers" determined on 200 cc. of hydrol- 

 ysate of prairie-covered loess, together with a comparison of similar 

 fractions taken from the Van Slyke analysis. 



1 By difference. 2 Calculated. 



Table XXIV. "Jodidi numbers" determined on 200 cc. of hydrol- 

 ysate of forest-covered loess, together with a comparison of similar 

 fractions taken from the Van Slyke analysis. 



17. Summary Tables. Certain of the preceding analyses have 

 been summarized in Tables XXV, XXVI. In Table XXV are 

 shown the amounts and percentages of soil dissolved by the acid 

 during hydrolysis as well as the amount of nitrogen and percentage 

 of the total nitrogen dissolved. Table XXVI summarizes average 

 nitrogen distribution of Tables V, VI, VII, VIII, IX, X, XI, 

 XII, XIII, XIV, XVI, XVII, XVIII, and XIX. 



Table XXV. Percentages of soil and of soil nitrogen dissolved 

 by hydrolysuig the different soil types. 



a The figures in this column were obtained by subtracting the "insoluble 

 humin nitrogen" remaining in the residual soil from the nitrogen figures ob- 

 tained by multiplying the original weight of soil taken (dry basis) by the 

 nitrogen content of the soil. These figures may or may not agree with the 

 figures obtained in kjeldahling a portion of the solution, due to experimental 

 errors, and perhaps to errors introduced in using a uniform factor (2.6) for 

 specific gravity. The figures in this column are free from any error of this 

 sort. 



