14 BOARD OF AGRICULTURE. 



employed be reserved for farther experiment, if the Board of Agricul- 

 ture should consider it expedient to pursue the investigation during the 

 next year, 



Jabez Fisher, 

 John Brooks, 

 Josiaii White, 



Committee of the Board. 

 Boston, March 1, 1859. 



As in the moral world, each individual should be held account- 

 able only for his own deeds of good or evil, so in the natural 

 world, each individual circumstance or condition should be 

 entitled to, and should receive, only the credit due to the influ- 

 ence exerted by itself as such. If this principle is admitted, 

 and we do not see how it is to be denied or controverted, an 

 experiment in that department of vital chemistry which applies 

 to the vegetable world to be of any value, must be conducted in 

 such a way as to isolate, so to speak, the particular item under 

 consideration, that the effects or results which follow may be 

 referred directly to their specific causes. In inorganic chemis- 

 try there is no difficulty in doing this. A single experiment is 

 often of equal value with a thousand, because all the surround- 

 ing conditions are perfectly known and controllable ; but in 

 agriculture the case is entirely different. Here the conditions 

 are either inappreciable, or out of our power to control, and it 

 is only by the aggregation of a large number of experiments, 

 that we can obtain through an average result, an approximation 

 to the exact relation between cause and effect. 



It was thought that a careful performance of this experiment 

 by a thousand or more of the best farmers in the State, would 

 give results of such a character as to enable us to determine to 

 a comparative certainty, the best depth of applying manures 

 upon all the different soils which are to be found under cultiva- 

 tion, and what variations might be required by differences in 

 the kind of manure used, the crop grown, the depth of plough- 

 ing, various meteorological conditions and other circumstances. 

 Pains were taken to give the directions in such a way that the 

 experiment should be readily comprehended and easily per- 

 formed, and all the conditions of each individual experiment 

 should be precisely the same throughout, except the particular 

 depth at which the manure was to be applied ; thus isolating 



