22 JOURNAI^ OF THE 



g"ation has shown that the process takes place in at 

 least three different sta«»-es, and is probably due to the 

 action of different organisms. Kmile Marchal (Bui. 

 Acad. Belg-ique 1893 (3) 25, 727 abs. Chem. Cent. Blatt. 

 1894 2, 97) isolated some of the most prevalent soil or- 

 o-anisms and studied their action upon org-anic matter. 

 He was enabled to isolate by means of alkaline g-elatin 

 and peptone some thirty different species, all of which 

 chang-ed organic nitrogen into ammonia. Fifteen of 

 the number were energetic in effecting this change. 

 The Bacillus Nycoides, one of the most abundant in . 

 nature, produced ammonia from i^gg albumen, legumen 

 and gluten. A temperature of ^ibout thirty deg'rees C. 

 and a slight alkalmity was most favorable to its devel- 

 opment. Messrs. A. Muntz and H. Coudon (Ann. Ag- 

 ron. 19, 1893 No. 5 page 209) found that Bacilli, Bac- 

 teria, Micro-cocci, and 3^easts produced ammonia in 

 sterilized soils fnmi nitrogenous fertilizers. The pro- 

 duction of ammonia then is not due to the action of any 

 one species, but a great number of organisms have the 

 power effecting this change. Ammonia once formed 

 passes very rapidly into nitrates. This is shown by 

 the facts that although these organisms are continually 

 producing ammonia, yet only minute amounts of its 

 compounds can be detected in soils. It is also formed 

 in numerous other processes of putrefaction and decay, 

 the greater i)ortion of which escapes into the air to be 

 again brought to the soil by snow, rain and dew. It 

 is, however, generally admitted that plants may ab- 

 sorb some ammonia through the leaves, but the amounts 

 obtained in this way are believed to be very small. 

 When any considerable time has elapsed after a heavy 

 application of ammonium compounds to the soil, only 

 traces are found, whereas nitrates can be detected 



