Fo ° df ° r in the soil. The nitric ferment is a microscopic plant 



somewhat like the yeast used for leavening bread, and 



224 for fermenting malt liquors; and under favorable con- 

 ditions of temperature and moisture, and in the pres- 

 ence of oxygen is propagated with marvelous rapidity 

 in the soil. One of the results of the life of this minute 

 plant is the formation of Nitrates. 



Nitration is extremely feeble in winter and at tem- 

 peratures below 40° F. almost entirely ceases. It is 

 most active at about 98° F. to 99° F., and is more rapid 

 in the dark than in bright sunlight. At temperatures 

 over 100° F. the formation of Nitrates rapidly decreases 

 and at 131° F. entirely ceases. As we have just stated, 

 it has been noticed that the nitric ferment thrives best 

 in the dark, hence, this is one good reason for making 

 compost beds under sheds or in sheltered situations. 

 When so made the conditions for nitrification are more 

 favorable and the beds are protected from the leaching 

 action of storms. 



To ensure rapid nitrification all the food elements 

 required by the nitric ferment must be present. The 

 ash ingredients of plants, phosphates, ammonia, car- 

 bonaceous matter, and an excess of oxygen must be 

 present. 



Peat containing much copperas, coal-tar, gas-lime 

 containing sulphites and sulphides, kill the ferment. 

 The Nitrate ferment is developed during the slow de- 

 cay of organic matter in all soils. 



Materials Used in Making Commercial 

 or Chemical Fertilizers. 



Nitrate of Soda or Chile Saltpetre 

 Nitrate of Soda occurs in vast deposits in the rainless 

 <S.it itr^ districts of the West coast of South 



America, chieny in Chile, Irom whence 

 it is imported to this country for use in chemical manu- 

 facture and in agriculture. As imported into the United 

 States, Nitrate of Soda usually contains about fifteen 

 per cent, of Nitrogen. Nitrate of Soda resembles com- 

 mon salt, with which and sodium sulphate it is often 



