74 BOARD OF AGRICULTURE. 



Dr. Sturtevant. Generally speaking. I am speaking 

 of agricultural soil. 



Mr. Whitaker. "Would not soil wliick contained a 

 large amount of vegetable matter be more likely to retain 

 the minerals that you placed in it than soil that contained 

 less vegetable matter ? 



Dr. Sturtevaistt. I don't- want to open that matter. It 

 will open up too extended a discussion. I don't want to 

 give any half truths. 



Mr. Whitaker. My experience is this, that if you take 

 clear sand, and try to pass water impregnated with foreign 

 substances through it, a large portion of it will be very 

 likely to pass through the sand; if that sand is mixed with 

 ashes or clay, it will not pass through so fast ; if that sand 

 and clay are mixed, say with very fine charcoal, or some 

 other vegetable partly decomposed, or decomposed almost to 

 become carbon, that* will help to retain the water : so that 

 the passage of the water really depends in great measure on 

 the condition of the soil. Now, I will tell you how every 

 one of you can try this experiment for yourselves, without 

 having to go back to any one. Just take a champagne 

 bottle, if you like, or any other bottle ; invert that, and break 

 the bottom off; fill it with sand within an inch or two of the 

 top ; and then put in your liquid, and see how it gets out of 

 the bottom. Then make a mixture of clay and sand, and 

 pour on your liquid in the same way ; then make another 

 mixture with very finely powdered charcoal, and try the -same 

 experiment. You will thus find how different soils will leach. 

 It is a simple experiment, and one that you can all test; 

 and we shall find, as a general thing, that we learn fully as 

 much from plain, simple experiments as we do from larger 

 laboratories, and they make an impression on our minds. 

 You will find that the mixture put into the bottle that con- 

 tains charcoal allows the least water to pass througli ; that 

 which has the clay comes next ; and the sand allow:s it to 

 pass off rather freely. So we are met in agriculture every- 

 where with a great many circumstances which modify our 

 opinions. 



Now, I should like to ask Dr. Nichols one question. He 

 says that a horse that is worked to a considerable extent 

 will void less nitrogenous and fertilizing matter in its excre- 



