THE CULTURE OP FAKM CBOPS. 



CHAPTER XII 



AMMONIA. ITS COMPOSITION, PROPERTIES, AND RE- 

 LATION TO VEGETABLE GROWTH. 



Ammonia has been previously mentioned as a compound 

 of nitrogen and hydrogen gases. It has some very inter- 

 esting and important properties in regard to organic mat- 

 ter, and has been made the subject of much study and ex- 

 periment by agricultural physiologists. It is a colorless 

 gas, but offers in its other remarkable properties, an instance 

 of the wonderful changes in matter made by chemical com- 

 bination. Its primary elements have .neither taste noi 4 

 odor, but when combined, this product has a most powerful 

 penetrating odor; a burning acrid taste : "extinguishes flame; 

 is not combustible as hydrogen is ; instantly suffocates ani- 

 mals; kills living vegetables, and corrodes their substance. 



It is absorbed in large quantities by porous substances ; 

 charcoal absorbs 95 times its own bulk of it ; peat takes up 

 a large amount of it, varying with its own condition ; decay- 

 ing vegetable matter also takes up and holds it in its mass; 

 porous soils, clay, and iron oxide mixed in the soils of a 

 red color, are capable of absorbing and retaining it within 

 their pores, when it is brought into contact with them. 



But water absorbs ammonia to a far greater extent than 

 any other substance. If a bottle filled with the gas is in- 

 verted in water, the water will instantly rush up and fill 

 the bottle, absorbing and dissolving the ammonia and occu- 

 pying its place. The solution of ammonia in water is 

 lighter than water to the extent of one-eighth; and has the 

 same properties as the gas itself. 



Ammonia is an alkali and combines with acids; changes 

 vegetable red colors to blue, and in combining with some 

 acid gases forms solid substances; as for instance when 

 carbonic acid gas is mixed with it, the two gases combine 



