9 6 SCIENTIFIC AGRICULTURE. 



7. What is zoology ? Why should the farmer know some- 

 thing of this science? What does geology treat of ? Why 

 should the fanner study it? With what does the mechanic 

 supply the farmer? What does physics treat of? Why should 

 the farmer have some knowledge of chemistry ? 



8. Why should the farmer have a general acquaintance with 

 the sciences mentioned ? What relation do they sustain to agri- 

 culture ? 



9. What sciences are of most importance to the farmer? 

 What improvements in farming implements are mentioned ? 



10. What benefits has agriculture derived from chemistry ? 

 n. How does the chemist proceed in his investigations? 



What is it proposed to show ? 



CHAPTER II. 



THE ORIGIN, COMPOSITION, AND CLASSIFICATION OF SOILS. 



12. What is the soil? Of what does it consist? Where 

 does the organic matter come from ? When burned, what is 

 left ? What do geologists suppose the earth to have once been ? 

 What happened as it cooled down ? Of what does soil consist ? 



13. What is meant by mechanical agencies ? What by 

 chemical? Give examples? Are these agencies always at 

 work? 



14. What is included under the term "rock"? What 

 agencies disintegrate rocks? How does water act? How 

 does thorough cultivation help this disintegrating action ? 



15. With what do the elements of a soil vary ? Does the soil 

 always rest on the rock from which it was formed ? What is an 



16. What causes the difference in the quality of soils ? Are 

 there many simple substances ? 



17. How many elements are certainly known ? Which are 

 gases ? Liquids ? Solids ? Are there any permanent gases ? 



18. How many elements are concerned in the growth of 



