828 



The process by which the loss of nitrofren may l>e prevented, that of 

 nitrification of ammonia, takes place, as is well known, extensively in 

 nearly all soils, and fn'qnently in the storing of barnyard manure when 

 the ventilation is sutficient- In tlie latter case the nitrification is 

 believed to be of no advantage, since reduction, the result of which has 

 been referred to above, is also going on in the fermenting mass. The 

 author refers to experiments bearing on the question of the loss of fi-ee 

 nitrogen in tlic processes of nitrification. Dcht'rain* and Tacket both 

 observed a loss of nitrogen in the nitrification of soils. Elirenberg.| 

 on the contrary, was nnable to note any loss of nitrogen, but in his 

 experiments the ventilation is said to have been incomplete. S<'hir>s- 

 ing's§ exi)eriments lead him to conchide tliat tlicre is not necessarily 

 a loss of nitrogen in nitrification, even when the latter is very ener- 

 getic. This lack of uniformity in tlu' results ulttained by tlilTerent 

 persons the author is unable to account for, luit more will be s;«id upon 

 this subject in the discussion of his experiments further on. 



The subject of the «.'nrichment of soils in nitrogenous <'omiM)unds at 

 the exi^Mise of the free nitrogen of the atmos|)here iscarefjilly leviewed 

 in all its Ix'arings. 



The author then reports experiments by himsilf which were made to 

 study the liberation of nitrogen in the decompositi(Mi of organic nitrog- 

 enous material in well-ventilated soil. The exjteriments were made 

 to settle the much disputed iiuestion, whether or not an escape of free 

 nitrogen accompanies nitrification. They were carried on in a closed 

 apparatus from which the air was excluded and which was ]»laced in an 

 «»ven at L'S^-;{L'" ('. The apparatus was tilled with a mixture of oxygen 

 and hydroi^en in the proportion to form water, which Avas sui»plied by 

 electric generators within the api)aratus. Prior to the experiment the 

 air in the apparatus was thoroughly expelled by the gas mixture, and 

 at intervals during the progress of the exi)erinu'Tit samples of the gases 

 were taken for analysis. Two sets of apjiaratus were used. The first 

 contained 14.S."i() grams of a mixture of 10 ]»arts of gnuind blo(Ml, .">(► 

 parts of garden soil, and 10 ])arts of calcium carbonate, the last being 

 introduce«l to present the most favorable conditions for nitrification. 

 The second apparatus containe«l 14..'»0(!1> grams of a mixture of .30 jiarts 

 of bone meal, 40 parts of soil, and 1L' ])arts of calcium caibonate. The 

 experinu'uts were cojninenced about the middle of March and <'ontinued 

 to the first of .lune. The results showed that in the first week, while 

 an «'in'rgetic ammonia lernientation was going on, there was either no 

 free nitrogen liberated or only mere traces. Later, during the course of 

 the saltpeter formation, it is believed the losses of free nitrogen were 

 relatively large. The amount of nitrogen liberated in the first 

 experiment was 16 c. c.=L'0 mg., ami in the second 9 c. c. = ll mg. 



' •Ann. Agron., 13 (1887), p. 24ll '~^'^ 



t I.aiulw. .T.ilirl.., 18 (1880). p. 439. 

 tZ.'itsrli. f. physiol. nii-m.. 11 (1887). p. It.".. 

 §C^'uip- rend., 108 (1889), ji. 'J05, an<l U)9, p.lL'3. 



