39 



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

 facts that will justify a broad and impregnable general- 

 ization, fit to be published, and constituting a noble con- 

 tribution 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 farmer has already suffered so much, — careless 

 statements and half-established conclusions, — you must 

 bring into the field exact weights and measures, exact ob- 

 servations 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 all sides. If 

 the case is one pertaining to an out-door crop, like wheat for 

 instance, consider the variety of elements 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, condition, 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 harvest- 

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

 ascertained that wheat subjected to one of the new ma- 

 chines, though fair in appearance, loses somehow a portion 

 of its germinating, or reproductive power; and finally, 

 not only the measurement but the weight of the yield, — 

 for, as you know, wheat of the same apparent plumpness 



