Jan. 6, 1919 Determination of Acidity and Nitrogen in Wheat ii 



Table IV. — Determination of phosphorus in wheat extract 



Tem- 

 pera- 

 ture. 



5 

 5' 

 5 

 5 



20 

 20 

 20 

 20 

 20 

 20 

 20 

 20 



40 

 40 

 40 

 40 

 40 

 40 

 40 

 40 



50 

 50 

 50 

 50 

 50 



Duration r:{ extraction. 



5 minutes . 

 30 minutes 

 I hour .... 

 24 hours. .. 



5 minutes. 

 30 minutes 



1 hour 



2 hours. . . . 



4 hours. . . . 

 8 hours. . . . 

 16 hours. .. 

 24 hours. .. 



5 minutes. 

 30 minutes 



1 hour 



2 hours. .. . 



4 hours. .. . 

 8 hoiu's. .. . 

 16 hours. . . 

 24 hours. .. 



5 minutes. 

 30 minutes 



1 hour 



2 hours. .. . 

 4 hours. . . . 



Total percent- 

 age of phos- 

 phorus in 

 the extract. 



O. 018 

 . 029 

 . 027 

 .083 



.044 

 .063 

 . 067 

 . 106 

 •159 

 •173 

 .208 

 . 190 



.099 

 .183 

 . 210 

 . 240 

 •253 

 •254 

 •257 

 •259 



. 162 



•215 



.236 

 • 254 

 .258 



Percentage of 

 inorganic phos- 

 phorus in 

 the extract. 



O. 019 

 . 020 

 . 020 

 . 070 



.031 

 .031 

 .050 

 . 062 

 .083 

 . 092 

 .098 

 •113 



.032 

 .116 

 . 146 

 .177 

 . 212 

 .223 



•25 

 .24 



. 109 



•151 

 . 172 

 . 220 

 . 196 



1. It will be noted that at 50° C. the total and inorganic phosphorus 

 increases with the time of digestion. 



2. At 20° C. the total and inorganic phosphorus increases with the 

 time of digestion, but the total phosphorus does not show any increase 

 after 16 hours. The ratio between the total and inorganic phosphorus 

 varies considerably, but the latter averages a little more than one-half 

 of the total. 



3. At 40° C. the total and inorganic phosphorus increases with the 

 time of digestion, but the maximum for both total and inorganic phos- 

 phorus is reached at about 4 hours. The proportion of inorganic phos- 

 phorus in relation to the total is much greater than at the lower tem- 

 perature. After four hours the inorganic phosphorus is almost equal 

 to the total. 



4. At 50° C. the maximum of both total and inorganic phosphorus is 

 reached in about two hours. The results are graphically presented in 

 figures 5 and 6. 



Why does hydrogen-ion concentration remain the same or show no 

 increase with the increased time of digestion, while the amount of N/20 

 barium hydroxid necessary to bring the solution to the concentration 



