EXPERIMENTAL FARMING. 351 



crop and the disease, either through a contaminated soil, or by 

 contact with diseased potatoes. 



Experiments with the potato might also be made, in regard 

 to its connection with the atmosphere. It is possible that the 

 source of the disease may be meteorological ; that it is some 

 effect produced by the atmosphere upon the vine, and commu- 

 nicated from the foliage to the tuber. But enough has already 

 been said to show that thousands of new facts it may be needful 

 to ascertain, before we can obtain a clue to the cause of the 

 potato disease. Let us not despair, however, until every possi- 

 ble mode of experiment has been unsuccessfully tried, of yet 

 discovering the means of averting this great calamity. 



12. It is highly important to learn the comparative profitable- 

 ness of scientific and empyrical farming ; understanding by the 

 former the custom of reducing enlightened theory to practice in 

 cultivating the ground, and by the latter the art of tilling the 

 ground by the rule of precedent and experience, and of fertiliz- 

 ing by composts prepared, not on chemical principles, but 

 according to rules ascertained by practice. The latter, or the 

 empyrical system, is the most certain and indeed the only safe 

 one in the hands of a merely practical farmer ; as the use of 

 decoctions for the sick is more safe in the hands of an uneduca- 

 ted physician, than the concentrated and to him unintelligible 

 drugs of the apothecary. But the question is not wdiether we 

 can substitute any thing better than compost, in the place of it, 

 under circumstances that render it abundant and easily pro- 

 cured ; but whether, under circumstances in which compost is 

 hard to be procured, the use of chemical fertilizers may not be 

 reduced to such method and science, as to be equally cheap, 

 sure and efficacious. 



Such experiments are constantly on trial by cultivators in 

 different parts of the world ; but they are no less worthy of 

 being tried on the society's farm. We cannot trust implicitly 

 to the published results of the trials of substances which form a 

 staple article of manufacture and commerce, because they are 

 invariably puffed beyond their merits, like patent medicines, by 

 those who are interested in their sale. The society, which is 

 not likely to enter into any commercial speculation by the man- 

 ufacture of fertilizers, may be considered a disinterested body, 



