THE FARMER'S BUSINESS 37 



earth. In this connection no truer statement was ever made than 

 that written more than three thousand years ago: 



In the sweat of thy face shalt thou eat bread, till thou return unto the 

 ground; for out of it wast thou taken for dust thou art and unto dust shalt 

 thou return. Gen. 3 : 19. 



The Great Work of Plants. The elements which compose an 

 animal body are gathered from various sources, and as such they 

 are only in one of the stages or forms in the cycles through which 

 they pass. A speck of phosphorus, for example, contained in an 

 animal body may have been gathered from a cabbage head or a 

 turnip ; it tarries there for a lifetime, then continues its wanderings 

 through the ages; and the only way it can again become a " build- 

 ing block" in an animal body is to become built up in the tissue 

 of some edible plant. 



Plants not only furnish building materials for animal bodies, 

 but they also supply them with fuel for heat and energy. Thus a 

 great work of plants is to bring together carbon, oxygen, nitrogen, 

 mineral elements and water and build them into foods for man 

 and beast. 



The Farmer's Business. Since man and beast must eat to 

 live and grow, the farmer's big business is to raise those plants 

 which have been found good for foods. Not only must he provide 

 foods but materials for clothing as well. In order that the farmer 

 might do this most successfully he must understand soils and the 

 principles upon which crop production depends. 



Demonstration. Materials Needed. Material and apparatus necessary to 

 generate and demonstrate characteristics of oxygen, hydrogen and carbon 

 dioxide gas: Samples of the elements aluminum, calcium, magnesium, sodium, 

 potassium, phosphorus and carbon; lime, wood ashes, one-fourth of a pound 

 of dry grass or clover hay, a baking powder can. 



1. Object. To demonstrate the properties of oxygen, aluminum, calcium, 

 magnesium, sodium, potassium, carbon, hydrogen, lime and carbon dioxide. 



2. Object. To explain the true meaning of potash. 



Procedure. Fill a baking powder can, having a perforated bottom, with 

 wood ashes and leach out the potash. Evaporate. 



3. Object. To show that plants contain mineral matter. 



Procedure. Burn about 4 ounces of dry grass or clover hay and note 

 the residue. 



Questions. (a) What are ashes? 



(6) Where did this material come from originally? 



(c) What escaped during the burning? 



(d} What part of clover hay is carbon? 



(e) What is the per cent ash content of clover hay? 



