408 BOTANICAL GAZETTE [MAY 
Total nitrogen 
Total nitrogen was determined by the ARNOLD-GUNNING method 
as modified to include nitrate nitrogen. This method is described 
by MaTueEws (6). 
Nitrate nitrogen 
The nitrate nitrogen was determined by the SCHLESING- 
WAGNER method as modified by Kocu. The method is described 
in detail by Woo (15) in his chemical study of Amaranthus. To 
test the accuracy of this method a five-tenths per cent solution of 
potassium nitrate was used. Theoretically, 2 cc. of this solution 
should give 2.22 cc. of gas calculated to standard conditions. 
The average result of several determinations was 2.15 cc., which 
was about 97 per cent of the calculated amount. The precaution 
necessary to insure the success of the process as described by 
Woo is that all the solutions must be entirely free from oxygen. 
The presence of oxygen tends to cut down the amount of gas 
absorbed, thus causing a low result. 
In making the determinations, aliquots containing 5 gm. of 
the original samples were extracted with two 100 cc. of water for 
one-half hour each. This extract was then treated with lead 
acetate to precipitate the proteins which caused much trouble 
unless removed. The samples were made up to volume of 250 cc. 
and filtered, then 100 cc. of the clear solution representing 2 gm. of 
the dry material was concentrated on the steam bath to about 
20 cc. and the NO gas determined. The following represents a 
determination as run in duplicate from a sample: 
Aliquots in 6. (a Ws ee a S00 
Total volume of gas pce Ae Re ee 1.66 cc 
Volume of unabsorbed gas ................ 6.0% >. 
Volume of absorbed NO gas................ O.98°: << 
Barometic pressure 749.7 mm., temperature.. 24.5 
Volume at standard conditions............. °. ce. 
Equivalent milligrams of KNO,............. 0.0076 
Equivalent milligrams of NO,.............. 0.005 
Discussion 
It is important to note the variation in the sulphur content of 
the hay from the widely separated districts. From the tabulated 
