26 



Now then, what happens? Limestone is a chemical product, it is made 

 up of elements. Now, elements are simple things. We do not always under- 

 stand what elements are; we do not always understand what compounds are, 

 but it would be worth a whole lot to farmers and farmers' boys if they did 

 understand these things. They would be more interested in the work they 

 are doing, because they can see what is going on. Just like we go on and 

 plant corn, cultivate it and finally produce an ear of corn. A whole lot of 

 things happen there that we did not think about. A great many chemical 

 changes take place. If we had an understanding of them there would be a 

 whole lot more interest in the work we are trying to do. 



I want to illustrate that by this little simple reaction. I am going to 

 put a piece of limestone here on the board in a different form probably than 

 many of you have ever seen before. It is written by the chemist in this 

 way: CaCOa. When 1. see that I can't think of anything else but lime- 

 stone. Just the same as if I write the word "Limestone". When you see 

 that you don't need to see the rock, do you? There it is. That word tells 

 you that is limestone. This formula means the same to the chemist. That 

 is limestone in its pure state. It is made up of three elements calcium, 

 carbon and oxygen. 



Now what is an element? This thing as it stands we call a compound. 

 Just briefly let us define an element. There are certain elements that exist 

 as elements alone. Sulphur is an element. No matter where we get hold 

 of a piece of sulphur it is sulphur and nothing else. Nothing else is com- 

 bined with it. Carbon is an element represented by "C". A good example 

 of carbon is charcoal. Now when I was a boy we used to take sulphur. I 



Showing how the terraces are started by back-furrowing two rounds. 

 Note the smooth curves. 



(Courtesy Missouri Experiment Station) 



don't believe we practice those home remedies so much as we used to. 1 

 asked an audience some while back what we used sulphur for and somebody 

 said, "We would use it if we had the itch." I don't know whether I had 

 the itch. Mother made us take it. She did not know why, but she made 

 us take it. It was supposed to do us good. How about charcoal? That is 

 supposed to be pretty good for a sour stomach, isn't it? 



Now look here at this interesting thing that happens. You can take 

 those two elements, mix them together, take them internally and it doesn't 

 hurt you, but you take the two simple elements, sulphur and carbon, mix 

 them together in the right proportions and apply heat which will finally 

 dissolve them and form a liquid and you will produce a product that is 

 poisonous carbon-bisulphite. A poison we use to put in our wheat bins 

 to kill weevil. You see how simple chemistry really is. 



