88 WHAT IS A SUCCESSFUL EXPERIMENT .? 



3. What is a successful experiment ? 



In pronouncing whether an experiment has been successful 

 or not, it is necessary to have a clear idea of the purpose for 

 which it has been made, and of its fitness to attain that pur- 

 pose under the circumstances in which it is tried. 



Generally, however, an experimental application may be said 

 to be successful, either economically or theoretically 



1. When it causes the production of a decidedly larger crop 

 than would have been raised without its assistance in the exist- 

 ing circumstances. 



2. When the crop, after paying the additional cost of the 

 application, leaves a larger profit than it would otherwise have 

 done. 



3. When it illustrates the mode of action of the substance 

 applied upon a given crop, in given circumstances or throws 

 light upon some obscure point, in theory or practice. 



4. In this sense it may often be considered successful when, 

 after repeated trials, it is found to produce no sensible effect 

 whatever. A decidedly negative result may often be as useful 

 as a positive one, not only by preventing the outlay of money 

 on the part of the practical man, but by clearly proving or dis- 

 proving some theoretical question. 



5. When it suggests new, further, and perhaps more inter- 

 esting experimental researches. 



In this last case, an experiment may prove of great value to 

 the theory of agriculture, and may ultimately be productive of 

 great benefits to the progress of knowledge. Indeed, all new 

 steps in knowledge are suggestive of further research ; and it is 

 one of the most valuable consequences of beginning to ex- 

 periment, with however little knowledge of the subject at 

 first, that a thinking and reading man comes by degrees not 

 only to see his way clearly through what he is actually doing, 

 but to ask new questions of himself, which new experiments, 

 probably never before thought of by any one, can alone 

 enable him to answer. Almost every result he obtains suggests 

 to him further inquiries, when its true meaning is perceived or 

 suspected ; and thus not only is a habit of strict investigation 



