8 



Journal of Agricultural Research 



Vol. XVI, No. I 



The figures given under first neutralization to Ph 8.3 are obtained as 

 follows: The number of cubic centimeters of NJ20 barium hydroxid 

 obtained by titrating to Ph 8.3 are subtracted from the number of cubic 

 centimeters obtained by titrating to Ph 9.3. This difference is added 

 to the figures in the last column of Table I. The figures so obtained are 

 assumed to be the same as if the formaldehyde had been added at the 

 concentration Ph 8.3 and then the titration resumed till the concentration 

 Ph 9-3 was obtained. The figures under first neutralization to Ph 7 

 were calculated in the same way except that the differences between the 

 number of cubic centimeters in the columns under Ph 7 and Ph 9.3 in 

 Table I were used. 



The calculations made on these assumptions show that the "formol" 

 or titratable nitrogen obtained by first titrating to Ph 8.3 and then 

 adding the formaldehyde is over twice that obtained by titrating first 

 to Ph 9.3 and then adding the formaldehyde. And further, if the for- 

 maldehyde is added at Ph 7 and the titration is then continued to the 

 concentration Ph 9.3 the amount is over four times as great. 



The results obtained by this method of calculation raises the question, 

 To what point of concentration should the solution be titrated before 

 the formaldehyde is added? To throw light on this point an extract 

 from wheat digested at 40° C. for four hours was used. It was 

 prepared as the other extracts used in this investigation. This 

 was then titrated to the points Ph 7, Ph 8.3, and Ph 9.3, first without 

 adding any formaldehyde, and second by adding the formaldehyde before 

 starting the titration. 



Corrections were made for the differenpes in volume of these two. 

 These corrections were o.i and 0.2 cc. The following results were 

 obtained (Table III). 



Table III. — Quantity of NI20 sodium hydroxid required for neutralization with and 



without formaldehyde 



One hundred-cc. portions of extract from the wheat prepared in the 

 same way were then used to see what differences would be obtained if 

 the formaldehyde was added after the titration had been made to the 

 following concentrations: Ph 7, Ph 8.3, and Ph 9.3. 



