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cessary ? How can he find time and opportunity to mas- 

 ter geology, chemistry, botany and physiology, and ap- 

 ply them in his daily pursuit ? And if success in his 

 culling is dependent on his profound knowledge of these 

 sciences, how a can he ever hope to succeed? The an- 

 swer to these questions is plain to him who observes and 

 reflects. Every farmer is not expected to master either 

 of these sciences, any more than he is expected to mas- 

 ter astronomy. But it does not follow because every 

 man is not, and cannot be an astronomer, that therefore 

 the truths of astronomy are useless, and Galileo, Kepler, 

 and Newton lived in vain. Every man cannot become 

 a mathematician, but who is there bold enough to deny 

 the value of mathematical science ? And so every man 

 cannot become a chemist, but the truths of chemistry 

 may nevertheless prove immensely serviceable to him. 



In all the sciences there are numerous principles and 

 results that may be learned and remembered by a little 

 application and that men habitually recognize and act 

 upon without being able to demonstrate the truth of a 

 single one of them. How many ships are safely navi- 

 gated from continent to continent, in accordance with 

 rules deduced by astronomical and mathematical science, 

 which rules the navigator obeys without understanding 

 the reasons of their existence. 



How many artisans shape their works in obedience to 

 geometrical laws who never in their lives saw a demon- 

 stration of the truth of those laws. And so when the 

 chemist, botanist or physiologist discovers a truth of 

 value to the agriculturalist, the latter may learn the fact 

 and successfully apply it though ignorant of the process 

 by which it was discovered. We all of us act upon this 

 principle every day of our lives. We take that to be 

 law which the judge declares is law, because we have 

 confidence in his honesty, ability and learning. For the 

 same reasons we take the potion that our physician pre- 



