Journal of Agricultural Research 



Vol. XVI, No. 1 



Table I. — Hydrogen-ion concentration of ivheat extracts made at different temperatures 

 and periods, together with the quantity of Njso barium hydroxid used in the titrating to 

 change the hydrogen-ion concentration 



Tem- 

 pera- 

 ture. 



5 

 S 

 5 

 5 



20 

 20 

 20 

 20 

 20 

 20 

 20 

 20 



40 

 40 

 40 

 40 

 40 

 40 

 40 

 40 



50 

 50 

 50 

 50 

 50 



Time. 



5 minutes. . 

 30 minutes. 

 60 minutes. 

 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 hours. . . . 

 16 hours. . . 

 24 hours. . . 



5 minutes. 

 30 minutes 



1 hour 



2 hours. . . . 

 4 hoiirs. . . . 



Volt 

 reading. 



663 



661 

 666 

 661 



662 

 ,662 

 ,667 

 ,663 

 ,661 

 ,661 

 ,661 

 ,656 



.650 



•655 



■ 654 



• 643 



• 654 

 •653 

 .651 



■ 654 



.651 

 .652 



•653 

 .648 



■655 



Ph 

 values. 



6.60 



6-57 

 6.65 



6.57 



6.58 

 6.58 

 6.67 

 6.60 

 6-57 

 6- 57 

 6-57 

 6.48 



6.36 

 6.46 

 6.44 

 6.26 

 6.44 

 6.43 

 6-39 

 6.44 



6-39 

 6. 41 



6.43 

 6.34 

 6.46 



Quantity of Ntzo barium hydroxid used 

 to titrate to — 



0.686 or 

 Ph 7- 



Cc. 



0-5 



•5 



• 4 



1-5 



1. I 



1-3 

 1-5 



2. 2 



3-4 

 3-4 



4-5 



1.9 

 3-4 

 4.4 

 4.9 

 5-2 

 5-7 

 6.3 

 6.9 



3-2 



3-5 

 4.0 



5-8 



5-3 



0.760 or 

 Ph8.3- 



Cc. 



1-3 



1.6 



5-5 



2. I 

 3-1 



14-3 

 16.8 



3-9 



7-4 



II. I 



14-3 

 17-3 

 17.9 

 18.0 

 18.2 



6.5 

 10. 4 



13-7 

 16.3 

 16. 4 



0.820 or 

 Ph9.3- 



Cc. 



2.8 



3-1 

 3-0 

 9.0 



4.9 



7-3 



8.8 



II. 8 



13-5 

 19. o 

 22. 4 



5-4 

 10. 7 



IS- 7 

 19. I 

 22. 4 

 23.8 



23 9 



24. I 



9.0 

 14.9 

 18.2 

 21. 4 



21-5 



Volt 

 reading 



after 

 adding 

 formiil- 

 dehyde. 



0.820 or 

 Ph9-3 

 after 

 adding 

 formal- 

 dehyde. 



Cc. 



0.778 



•785 

 .790 



.778 



•763 

 .761 



•763 

 .768 

 .770 

 . 762 

 .770 

 .770 



.780 

 .771 

 .772 

 . 762 

 .772 

 .776 

 .776 

 .780 



. 762 

 .770 

 •774 

 •774 

 . 780 



Cc. 



2.9 



3-1 

 3-5 

 3-7 

 4-4 

 4-7 

 4-9 



^•7 

 2>-2> 

 3-7 

 4-3 

 4. I 

 4.0 

 4. I 

 4.2 



3-5 

 3-6 

 3- I 

 3-2 

 3-0 



The data in Table I show the following results : 



1. The average hydrogen-ion concentration of the extracts obtained 

 at 5° C. is Ph 6.60; at 20° C. it is Ph 6.59; at 40° C. it is Ph 6.43; and 

 at 50° C. it is Ph 6.52. Thus, the higher temperature gives an extract 

 of slightly higher hydrogen-ion concentration. 



2. The hydrogen-ion concentration does not increase with the dura- 

 tion of digestion. The average volt readings at 40° C. for 5 minutes, 30 

 minutes, and i hour is 0.653, corresponding to Ph 6.43. The average 

 volt readings for 8, 16, and 24 hours are also 0.653, corresponding to 

 Ph 6.43. The longer or shorter period of digestion does not increase nor 

 decrease the hydrogen-ion concentration. The sHght variations obtained 

 at 20° and 50° for the different periods are so small that they do not 

 modify the above statement. 



