46 EVILS RESULTING FROM BAD EXPERIMENTS. 



upon another spot to which this manure has not been applied. 

 But to ascertain the precise effect of this one influence, every 

 other influence likely to modify it must be excluded. This is a 

 requirement of vital importance one exceedingly difficult to 

 be attained ; which requires attention to many circumstances ; 

 which has been very frequently neglected ; and which, as I shall 

 hereafter show, has not only led to very discordant results in 

 different places, but has greatly lessened the value of nearly all 

 the field experiments that have hitherto been published. 



The reader will see the necessity of not only accurately 

 observing and recording results, but of tracing and attributing 

 them to their precise causes, if he considers the evils that flow 

 from the publication of experimental results which have not 

 been carefully attained. Thus a badly made or imperfectly 

 observed and criticised experiment, is- not merely time and 

 money lost, but it leads 



1. To the adoption and introduction, among our received 

 views and into our standard books, of incorrect results, and of 

 erroneous deductions and opinions. Thus error is perpetuated, 

 and becomes every day more widely spread, and more difficult 

 to be afterwards removed or eradicated. 



2. To loss of money in practice by the evil advice it gives. 

 Practical men, for example, who are ill able to afford it, may 

 be induced by a published result to expend money on 

 manures, or on methods of improvement, which, in their circum- 

 stances, are unworthy of attention, and can only lead to loss. 

 Every one who is at all interested in the art of husbandry will 

 see the economical importance of this observation, and will in 

 all probability recollect cases in which such loss has actually 

 been sustained. 



3. To the neglect of further researches or experiments of a 

 similar kind, on the part of purely scientific agriculturists. The 

 belief that a thing is already done that certain published 

 experiments have explained or established it is a sure bar 

 against further inquiry ; and a belief of this kind has caused 

 important theoretical principles to encumber our works upon 

 scientific agriculture, and, to a certain extent, to guide our 

 practice for many years, which more accurate experimental 



