04 PRACTICAL FARM CHEMISTRY. 



mixed with oxygen, rest upon every acre. This is 

 many hundred times as much as any 



from theTir. ^^^P could use, if it were in the proper 

 form for plant food, which it is not. A 

 considerable amount of speculation has been wasted 

 on this subject. Here we have the two elements in 

 greatest abundance, which combined, are so expen- 

 sive to procure, and which are just what our soils 

 need to make them rich; and if we could induce the 

 two free elements to enter into a chemical union, at 

 little cost to ourselves, we would have no need of 

 going to South America for nitrate of soda and salt- 

 petre, nor be concerned about where to get nitro- 

 genous fertilizers. The material is on hand, and 

 yet we cannot get it in shape for the use of plants. 



There are analogous instances in our relations 

 with chemistry. In water we have an inexhaustible 

 supply of a chemical compound which, if we could 

 but separate the chemical union, at little cost, and 

 get the two elements, hydrogen and oxygen in their 

 free, elementary state, would give us fuel and light 

 much more powerful than coal or gas. Here again 

 we have free access to the materials, and yet we 

 cannot utilize them with economy, merely because 

 the separation of the two elements would require 

 the same energy that they produce, and no more. 



We also know that the chemical combination of 

 hydrogen, oxygen, nitrogen and carbon, in certain 

 proportions, with a little seasoning of sulphur, 

 phosphorus and other elements, gives us our steak 

 for our breakfast, the mutton chops or fish for our 

 dinner, and the cake for our tea; and while all these 

 elementary materials are plentiful in nature, we 

 would soon starve if we had to depend on making 

 the combination in an artificial way. It is a pity 



