May 10,1924 Nitrate and Amrnonia in Nitrogenous Materials 
535 
Table V .—Comparison of the modified Strowd and Ulsch-Street methods for nitrate 
in fertilizers —Continued 
Number 
Modified Strowd 
method for recovery 
of added nitric N 
Ulsch-Street method 
for recovery of added 
nitric N 
Filtered 
Not 
filtered 
Filtered 
Not 
filtered 
63902__ . 
Per cent 
b 15. 87 
6 15. 97 
d 15. 92 
Per cent 
c 16. 24 
* 16. 10 
Per cent 
Per cent 
c 16. 10 
* 15. 99 
Average_ ____ 
16. 17 
16. 05 
64026_ _ 
6 12. 80 
6 12. 42 
d 12. 28 
c 12. 28 
c 12. 23 
c 11. 92 
c 12. 19 
Average__ 
12. 26 
12. 06 
64773_ 
100. 0 
99. 1 
98. 8 
97. 7 
a 90. 2 
« 95.1 
77.5 
Average__ 
99. 6 
98. 3 
86.3 
64776____ 
96. 8 
98. 9 
97.7 
99.1 
86. 1 
Average_ 
97. 9 
98. 4 
64777... 
98. 3 
99. 7 
98. 8 
94. 2 
78. 0 
79. 2 
Average__ 
99. 0 
96. 5 
78. 6 
64813___ 
99. 1 
96. 5 
98. 6 
97. 7 
97. 7 
98. 8 
85. 3 
Average_ _ 
98. 1 
98. 1 
64828_ 
98. 6 
95. 4 
97. 1 
98. 3 
82.4 
Average—__ 
97. 0 
97.7 
& Total nitrogen in original sample by Kjeldahl-Gunning-Arnold method was modified to include nitrate 
and CuSO* used but no Hg. 
c Nitric nitrogen found in original sample by method indicated. 
a Nitric nitrogen found in original sample by the fertilizer department according to the ferrous sulphate- 
zinc-soda method. 
There was a slightly better recovery of the nitrate by the Strowd method 
but the results by both procedures are good except in those determinations 
where the flasks were connected at once with the condenser, in which case the 
results were lower. Here, as in the experiments where the nitrate alone was 
used, the results were contrary to what would be expected if there had been 
a loss of ammonia through the Bunsen valve. 
The results show that a better recovery of the nitrate was made by the modified 
Strowd than by the Ulsch-Street method. A slight modification of the latter 
method to provide a better reduction and distillation proved of decided advan¬ 
tage. This is shown in those determinations where the reduction was for 10 
96036—24f-4 
