able, and because, when it is available, it tends to leach from the 

 soil. It is available when it is in the form of a nitrate — one part 

 of nitrogen, three parts of oxygen, united with one part of some 

 other element (Na NO^, nitrate of soda ; K NO,, nitrate of 

 potash or saltpetre; H NO^. nitric acid, etc). Th^' process of 

 changing nitrogen into nitrates i.s called nitrification. This pro- 

 cess is the work of germs or microbes in the soil ; and these 

 germs work most efficiently when the soil is not water-logged, 

 and when it is well tilled. The farmer should make his nitrogen 

 supply as he goes along ; and he makes it with tile drains, plows, 

 harrows and cultivators. 



But there are some plants which have the power of using the 

 nitrogen which is in the air in the soil. These are legu- 

 minous plants, — clovers, peas, beans, vetch, alfalfa. If there- 

 fore, the farmer cannot secure sufficient nitrogen by other means, 

 he may use these plants as green-manures. If his S3\stem of 

 farming will not allow him to use these plants, or if he does not 

 secure sufficient nitrogen when he does use them, then he can go 

 to the warehouse and buy nitrogen. 



12. The soil is not a mere inert mass : it is a scene of life and 

 activity. — This is the new and the true teaching. Soil which is 



wholly inactive is unproductive. Movements of air and water, 

 actions of heat and evaporation, life-rounds of countless micro- 

 scopic organisms, decay and disintegration of plants and soil 

 particles, — these are some of the activities of the fertile soil. If 

 our ears were delicate enough, we could hear the shuffle of the 

 workers, the beating of the hammers, and the roll of the tiny 

 machinery. All things begin with the soil and at last all 

 things come back to it. The soil is the cemeter3^.of all the ages, 

 and the resurrection of all life. If the soil is not idle, neither 

 should the farmer be. 



NoTK. Persons who desire to pursue this subject further should procure 

 King's book "The Soil," and Roberts' " Fertility of the Land." Pub- 

 lished by the Macmillan Co., New York, at 75 cents and I1.25 respectively. 



