PREFACE. XI 11 



asserted that the facts are themselves denied. If science 

 declares that we have made progress in substituting 

 for deficient farm-yard manure its active ingredients, or 

 tliat superphosphate of hme is no special manure for 

 turnips nor ammonia for corn, it is imagined that the 

 utihty of these substances is contested. 



Long disputes have arisen about misconceptions of 

 this kind. The practical man does not understand the 

 inferences of science, and considers himself bound to 

 defend his own views. The contest is not about scientific 

 principles, Avhicli he does not understand, but about the 

 false conceptions he has formed of them. 



Until this contest is ended by agriculturists themselves 

 taking an active part in the matter, science can offer no 

 effectual aid. I am doubtful if this time has yet arrived. 

 I build my hopes, however, on the young generation 

 who enter upon practice with a different preparation 

 from their fathers. As for myself, I have reached the 

 age when the elements of the mortal body betray a 

 certain tendency to commence a new circle of action, 

 when we begin to think about putting om^ house in 

 order, and must defer to no later period what we have 

 still to say. 



As every investigation in agriculture requues a year 

 before we have all the facts before us, I have scarcely 

 any prospect of living to see the results of my teaching. 

 The only thing that remains for me to do, under these 

 circumstances, is to place my views in such a manner 

 before the public, that there can be no possibility of 

 misconception on the })a.rt of tliose who will give tlieiii- 



