386 SELECTIONS FROM ADDRESSES. 



be like regarding the half as larger than the whole. But the 

 fact that half of the matter in a bushel of grain can be spared 

 without a serious diminution of the fertilizing power of the 

 other half representing the whole, suggests the inquiry, whether 

 it is not practicable to separate still more of the carbon (coal) 

 and elements of water, known to form more than ninety per 

 cent, of most crops, and thus render all manure produced on 

 the farm, or in cities and villages, far more portable? Why do 

 one hundred pounds of guano often add one thousand to a crop 

 of potatoes, seven hundred to one of corn, or three hundred to 

 one of wheat ? If the essential elements of fertility in land 

 can be concentrated at all by art and science, in imitation of 

 nature in forming the dung of birds and nightsoil, who does not 

 see that there is opened to the husbandman a new and in- 

 viting field for research and discovery ? Young men who may 

 now be disposed to limit the resources of nature within narrow 

 bounds, for the production of the invaluable fruits of the earth, 

 will live to see how greatly they were mistaken. 



An acre of soil one inch in depth weighs about one hundred 

 tons. The roots of clover descend from twenty to thirty inches 

 in search of their appropriate aliment ; and I have traced them 

 to a greater depth. By estimating the mass of earth to the 

 depth of only twenty inches as available for agricultural pur- 

 poses, we have 2000 tons of soil and subsoil in an acre. Now, 

 so small an amount of gypsum as fifty pounds has added over 

 1000 to the clover hay grown upon an acre ; and 100 pounds 

 have increased the crop more than 2000 pounds. 



Where did the matter come from which formed this immense 

 gain in the weight of the harvest ? 100 pounds of plaster of 

 Paris really contain a fraction less than eighty of lime and the 

 oil of vitriol ; the other twenty being what is called " water of 

 crystalization." As gypsum operates with marked eff'ect on 

 limestone soils in western New York, where the use of lime 

 alone does no good whatever, I am induced to regard the sul- 

 phur in this fertilizer as the element that really adds so largely 

 to the growth of vegetation. Doubtless it will appear incredible 

 to you that i8| pounds of available sulphur in 100 of gypsum, 

 should cause the organization of some 95 pounds of carbon 



