130 Practical Farming 



Micro- There is also a wide difference in the fer- 



organisms as ^ilizing value of the soHd and Uquid portions 

 a Manurial ,> ■, r • i r ^i -^ 



Factor ^^ ^^^ manure of animals, so far as the nitro- 



gen is concerned. Carefully conducted ex- 

 / periments have shown that, as compared with nitrate 

 of soda, the sohd parts of the manure have an effec- 

 ^veness of but lo per cent.j while the liquid part has 

 an effectiveness of 90 per cent, as compared with the 

 nitrate, which is very nearly equal to that of sulphate of 

 ammonia. The nitrogen of the liquid portion of the 

 manure is very rapidly converted into ammonia, and thus 

 may rapidly escape into the air. It has also been shown 

 that the effectiveness of the nitrogen in the solid materials 

 of the manure is not increased by mixing with them the 

 liquids, but that the conversion of the nitrogen in the 

 urine into ammonia is hastened by the admixture of 

 the solid excrement and straw. The changes in manure 

 are carried on by microscopic organisms, which multiply 

 with inconceivable rapidity, and thus accomplish wonderful 

 results. 



These micro-organisms or bacteria are plentiful in the 

 manure as soon as it leaves the animal body, and it is be- 

 lieved that many of them come from the stomachs of the 

 animals along with the excrement. The air of the stables 

 always swarms with them, and the latter furnishes myri- 

 ads; and, since we can detect the smell of ammonia at 

 once, it is evident that they are promptly at work. Some 

 of these bacteria are denominated aerobic, since they 

 require the oxygen of the air in order to hve and grow; 

 while others flourish only in the absence of air and are 

 therefore termed anaerobic. Those that require air for 



