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Here is limestone. We are going to put that on a soil that is acid. 

 Now, let's see. Limestone plus acid, we will take hydrochloric acid, 2HCL. 

 It happens in chemistry that it takes two pounds of HCL to react with one 

 pound of CaCOs, so we write "2" before the HCL. Chemical action is just 

 like simple arithmetic, if we don't get too deep into chemistry. 



I will write another equation. Two plus two plus four equals what? 

 Any child will tell us it will equal eight, or it will equal four plus four. 

 Anybody can understand that. A chemical equation is just exactly the same 

 thing. We bring these two things together. They unite. This calcium 

 hooks on to that chlorine and forms CaCl 2 , plus this carbon, this oxygen, 

 hooked up with that and forms H 2 CO 3 , which is another acid; by bringing 

 the three things together the limestone and acid unite and form a salt that 

 is harmless to the soil, another acid that is a weak acid, that can't exist as 

 such, and this acid breaks up into H 2 O (water) plus C0 2 (carbondioxid). 

 The water remains in the soil without harm, and the CO 2 passes into the air 

 in the form of a gas. No matter what kind of acid is in the soil that re- 

 action takes place and produces a salt that doesn't do our soil any harm. 

 That salt is closely related to another salt that you use every day, NaCl. 



Now I wonder if I have gotten into too deep water, but that is all there 

 is to putting lime on your soil. What I am getting at, friends, is this: if 

 you have a boy that is interested in farming, like Mr. Meis' boys, if he under- 

 stood this simple thing wouldn't it mean more to him when he limes his soil, 

 if he knows just what happens, than if all he would know is "I am putting 

 lime on here just because Smith says so"? 



That is as far as I am going into chemistry in these problems that we 

 consider complex and it just depends on how deep we go. Mr. Mann can 

 go into the problem of phosphorus and he can put equations on the board 

 that none of us can translate because he has gone into the subject not only 

 from the practical standpoint but from the chemist's standpoint. However, 

 we don't all need to go into the subject that deeply. We do not all need 

 to know it as the chemist knows it. I am giving you this more for your 

 boys. If you have got a boy give him a little simple chemistry. 



LAND TERRACING SAVES WASHING. 



There is one more hobby that I want to present. I take it that this 



View of terraces after a rain showing how they catch the soil and 

 also how they check the flow of water down the slope and carry it around 

 the hill. 



(Courtesy Missouri Experiment Station) 



