38 
BULLETIN 1187, U. S. DEPARTMENT OF AGRICULTURE. 
hydroxide solution, using methyl red as the indicator. Correct for 
blank on reagents and calculate first, the percentage of nitrogen, 
and then the percentage of protein by multiplying the per cent of 
nitrogen by 5.7. The apparatus for making protein tests is shown 
in Figures 22, 23, 24, and 31. 
Fig. 30. — Electric furnaces used in making ash determinations on flour. 
In cases where extreme accuracy is not needed, where the sample 
is very small, where time is a factor, or where it is necessary to dis- 
tinguish with certainty between samples with a medium and those 
with either a high or low nitrogen content, a great saving in time 
can be effected without seriously lessening the accuracy of the 
determination by using wholewheat kernels instead of ground material. 
