AGRICULTURAL EXPERIMENTS. 455 



throughout the country, the sounder your basis for an induction. 

 Then let these records, bearing the stamp of more precision 

 than is common in county reports hitherto, duly and responsibly 

 authenticated, be brought together and collated by competent 

 hands, — and you have got a body not of theories but of facts, — 

 facts that will justify a broad and impregnable generalization, 

 lit to be published, and constituting a noble contribution to 

 substantial science. 



One prime difficulty that will attend these processes will be 

 an inadequate sense of the liability to deception. If you would 

 meet those enemies to real advancement from which the fiarmer 

 has already suffered so much, — careless statements and half- 

 established conclusions, — you must bring into the field exact 

 weights and measures, exact observations of climate and 

 weather, exact attention to every element that may influence 

 the result. Such credulous rules of evidence as suffice for tea- 

 table gossip, or stories of table-rappings, will not answer. 

 There must be a search for disturbing causes, not on one side 

 only, but on all sides. If the case is one pertaining to an out- 

 door crop, like wheat, for instance, consider the variety of ele- 

 ments you have got to watch and include in your report. There 

 is, first, the quality, species and pedigree of the seed sown ; there 

 is the time of sowing ; there is not only the composition of the 

 soil, but its mechanical preparation, its comminution by plough 

 and harrow, its situation as regards exposure to the sun, latitude^ 

 springs of water, and the antecedent crops taken from it ; then 

 there is the whole subject of manures, as to ingredients, condi- 

 tion, amount, and mode and time of application ; then the direct 

 treatment of the crop on the ground ; the cost of labor ; then 

 the subtle and fugitive meteorological changes ; then the relation 

 of the growth to diseases ; still further, there is the harvesting 

 threshing, and winnowing, — for it has lately been ascertained 

 that wheat subjected to one of the new machines, though fair in 

 appearance, loses somehow a portion of its germinating, or re- 

 productive power ; and finally, not only the measurement but 

 the weight of the yield, — for, as you know, wheat of the same 

 apparent plumpness ranges over a difference of five or ten 

 pounds' weight to the bushel. Now, it is not till you have 

 brought into your registration each of these twenty-three speci- 



