28 EXPERBIEXT STATION. [Jan. 



grams of manure (analyzing .05 per cent, of nitrogen and G8.57 

 per cent, of moisture) were placed in a glass vessel and enclosed 

 within a bell glass similar to the ones used in the above tests, 

 with the exception that the bell jar was provided with glass 

 tubes for the ingress and egress of air. The air passing into 

 the bell jar was made to pass through a solution of sulfuric 

 acid to remove anj traces of ammonia which might be present 

 in the atmosphere. Upon leaving the bell jar the air was made 

 to pass through a standard solution of half normal hydro- 

 chloric acid, which was to absorb any ammonia which might 

 be given off in the process of decomposition of the manure. 

 The exit tube from the flask of standard hydrochloric acid was 

 attached to an aspirator to provide a steady current of air 

 through the apparatus. The apparatus was made perfectly air- 

 tight by sealing, so that no air could enter the bell jar except 

 by first passing through the sulfuric acid arranged to remove 

 all traces of ammonia. An analysis of the standard solution of 

 hydrochloric acid at the end of the experiment showed the fol- 

 lowing amount of nitrogen, expressed in fractions of a gram 

 .001709. The infinitesimal amount of nitrogen liberated may 

 be due to the fact that the steady current of dry air which was 

 constantly passing through the bell jar removed the greater 

 part of the moisture from the manure, thus retarding and pre- 

 venting its natural decomposition. 



For the purpose of verifying the results of the foregoing ex- 

 periments a series of tests was instituted similar to those pre- 

 viously descril)ed, with the exception that 50 grams of each 

 fixer were used and the experiment covered a much longer 

 period of time, beginning March 21, 1901, and continuing 

 through the spring and summer, concluding Feb. 1, 1902. 



In the following table the first column shows the amount of 

 nitrogen contained in 450 grams of the manure. The second 

 column shows the nitrogen given off during the experiment, 

 both in grams and percentage, as determined by a chemical 

 analysis of the manure samples before and after the experiment. 

 The third column shows the nitrogen absorbed as determined by 

 a chemical analysis of each fixer at the conclusion of the ex- 

 periment. 



