were collected on April 25, 19 14. Section 281 had received but one 

 application at the rate of 12.5 kilos per 100 sq. ft. on December 3, 1913, 

 while applications at the rate of 1250 g. per 100 sq. ft. were made to Section 

 264 at 15 different intervals of about two weeks after December 20, 19 13. 

 Analyses were made of upper and lower portions of the plant separately 

 in order to show any localization of nitrogen in the more vigorously grow- 

 ing portion of the plant. 



Table V. — Total Nitrogen Determination on Foliage. 



Sample No. Plant No. Section. Portion. Condition. Nitrogen. %. 



I I 



2 



3 4 



4 



5 I 



6 



7 II 

 8 



9 4 

 10 



II 11-15 



12 



13 16 



14 



15 20 



16 



17 7 



18 



The total nitrogen content of the plants varied from once and a half to 

 more than twice the normal value found in the previous set. Average 

 values for the plants from Section 264 are 6.44% and 4.43%, respectively; 

 for those from Section 281, 4.63% and 3.24%. In each case the more 

 vigorously growing portion contained the larger percentage of nitrogen 

 and the increase over the lower portion is considerably greater in the 

 section to which the smaller applications were made during the entire 

 season. No clear relation is shown between the nitrogen content and 

 the degree of injury. Considerable tolerance for ammonium sulfate is 

 shown when it was applied to the soil in quantities not heavy enough to 

 produce immediate, serious injury. The fact that the dead plants had no 

 higher total nitrogen content than those only injured is evidence that part 

 of the nitrogen when added in small quantities was changed to a nontoxic 

 form, since the dead plants were in this condition as early as March 21, 

 while the living ones though injured undoubtedly continued to take up 

 the salt in solution until samples were taken. 



A series of ammonia determinations was made on the sap from "checks" 

 and ammonium sulfate fed plants of the set of 1 2-9-14. Folin's micro- 

 method for the determination of free" ammonia was used, the excess of 



