May io, 1924 Nitrate and Ammonia in Nitrogenous Materials 
531 
THE RECOVERY OF ADDED NITRATE IN THE PRESENCE OF TOBACCO 
The plan of this experiment was to digest the cured, pulverized tobacco in 
distilled water for 30 minutes by shaking every minute during the first and last 
five-minute periods. It was then filtered and two aliquots, each representing 
0.7 gm. of tobacco were withdrawn. To one was added either 0.25 gm. or 0.5 
gm. of sodium or potassium nitrate. Both determinations were made simul¬ 
taneously and the difference in the nitric nitrogen obtained represents that 
recovered from the added nitrate. No material differences were found in the 
different quantities and kinds of nitrate used. Some determinations, also, were 
made by connecting the flasks at once with the condenser and these are so desig¬ 
nated in the table. The tobacco samples were selected for their low nitrate 
content. Three contained 0.04 per cent and No. 80078 only 0.05 per cent 
nitric nitrogen. The results obtained are given in Table III. 
Table III —Recovery of added nitrate in the presence of tobacco 
Number 
Strowd 
method 
Modiflec 
met 
With Bun¬ 
sen valve 
1 Strowd 
hod 
With con¬ 
denser 
80078_ 
Per cent 
97. 1 
95. 2 
Per cent 
97.4 
98. 3 
95. 1 
97. 3 
97. 5 
96. 5 
Per cent 
91. 3 
88. 1 
Average____ 
96. 2 
97. 0 
89. 7 
80236 _ ______ 
98. 5 
94. 2 
97. 7 
89. 2 
Average _ __ 
96. 0 
80247_ __ _ 
99. 3 
98. 3 
97.2 
88. 3 
Average __ _ 
97.8 
80274 _ ___ 
98. 4 
97. 5 
95. 5 
97. 5 
Average _ _ 
96. 5 
A COMPARISON OF THE TWO PROCEDURES FOR NITRATE IN TOBACCO 
Two aliquots prepared in the same manner as previously described, each 
representing 0.7 gm. of the cured sample, were withdrawn from the same filtered 
aqueous extract of the powdered tobacco. One aliquot was used for the deter¬ 
mination and the other as a control, the latter having no Devarda alloy added. 
Some determinations, also, were made by the Strowd method in which the pre¬ 
liminary heating was for two hours instead of the prescribed one-hour period. 
The samples represent different grades of leaf, both of Burley and dark tobacco 
grown in Kentucky. The results obtained are given in Table IV. 
