184 Lessons in Nature Study. 



things. We will dig up a few pounds of top-soil and put it 

 on a board. Now let us mix it until it is fine and all alike 

 throughout Now let us weigh out exactly a pound. 



Charlie, can you weigh it ? Here is a pound. How 

 many ounces is that ? Now we will feel of it. Is it dry ? 

 No, it is moist. How can we get the water out of this soil ? 

 That is right. We must dry it We will put it in paper and 

 carry it back to school and put it under the stove or over 

 the heater for several hours. Mary may stir it at recess, 

 and Georgie may stir it at close of school. To-morrow we 

 will weigh it once more to see if it has lost any of the water. 

 When the soil has had time to dry in the air, have it weighed 

 once more. It will be found to have lost some of its 

 weight. This is called " air-drying." Record the loss of 

 weight by drying. Later question as follows : The soil lost 

 some of its weight when we dried it. Did all the water pass 

 away ? Is it perfectly dry ? Let us see. Here is a tin pan. 

 Let us put the soil in the pan and set it in a hot oven. Per- 

 haps Mrs. Martin, across the way, will let us use her oven. I 

 will ask her myself. We will put it into the oven and leave 

 it there until noon. How long will that be, Charlie ? Yes, 

 it will be nearly three hours. This is called " kiln-drying " 

 or " fire-drying." 



When dried thoroughly, we will weigh it again. Now 

 how much has it lost ? Now if we could get rid of the veg- 

 etable matter, we would be able to tell how much mineral 

 matter there is in this pound of soil. 



How can we get rid of the vegetable matter ? Can we 

 pick it all out ? Oh, no ; we must burn it out. Let us now 

 put it on this flat fire-shovel and put it into the stove and 

 leave it there. We must stir it once in a while, but be care- 

 ful not to push any off the shovel. What part burns ? Yes, 

 it is the vegetable matter which burns. Will the sand or 

 clay part burn ? Oh, no ; they cannot burn. How does it 

 burn ? It does not burn with a flame. No ; it smokes and 

 smoulders away. The vegetable matter is going up the 

 chimney now. Can you see it ? It is smoke. When it 



