62 BOARD OF AGRICULTURE. 



planted the field with corn. Where this heap had stood the 

 corn looked burnt, and when the dry time came on, the 

 surface of that ground, four inches below where the manure 

 lay, was covered with nitre. You will find that it will permeate 

 the soil for as much as eight or ten inches. The soil seems 

 to have a wonderful affinity for the salts of manure. You will 

 find that water from a manure heap, running over a ploughed 

 field, will lose all its coloring in running a few rods, and be 

 perfectly white. Nature always manures upon the surface. It 

 is a question whether the benefit of manure will not always be 

 as great placed upon the surface as in any other position. I 

 have seen manure spread upon a gravelly knoll in a pasture, 

 and left upon the surface of the land, and the result was most 

 excellent. 



Mr. Grout. — I rise for the purpose of putting an inquiry in 

 regard to the basis we are working upon. "We are treating of 

 soils for the production of corn. To get that corn we are 

 obliged, here in New England, to use manures ; and the appli- 

 cation of manures is of course a very important item in the 

 case, and, in connection with it, the kind of manures to be used 

 on different soils. I should be glad to hear from Dr. Hartwell 

 and Mr. Bull the character of the soil in the cases to which 

 they referred. Professor Agassiz suggests a questit)n in regard 

 to the depth to which the roots of corn penetrate. I have 

 examined that matter myself, and I have found the roots about 

 two inches under the surface. They do not run to a very great 

 depth. They need the heat of the sun, and sometimes the 

 moisture of the dews will affect the roots of the corn. They 

 perfectly permeate the whole surface ; they reach into every 

 particle of manure that is applied there. I once, in cultivating 

 some potatoes, found that the roots ran nearly across the row. 

 Thinking it would injure the crop to hoe them, I left three or 

 four rows to see what the effect would be, and I don't think I 

 had half as many in those rows as where I hoed. 



Now, the application of manure, unless we know the kinds of 

 soil as well as the season in which it is to be applied, is like 

 prescribing the same kind of medicine for all sorts of diseases. 

 We cannot safely calculate upon the effect. I think we ought 

 to understand the character and composition of the soil, and 

 what kind of manure is required for different soils. ' Unless we 



