96 THE PRINCIPLES OF ENGLISH AGRICULTURE. 



generally that the advantage of draining is that it causes the 

 passage from the dormant condition of soil into the active 

 condition. I have no doubt that it does. We might add 

 this to the previous considerations. The free entrance of air, 

 the free entrance of water charged with carbonic acid gas, the 

 constant contraction and expansion of the soil, all help to 

 reduce soils and to reduce the mineral matter of soils from 

 an insoluble and unavailable condition into an active and 

 available condition. But there are a great many more con- 

 siderations, and those considerations we ought to see brought 

 out in the answers which are given to such a question as this. 



Unfortunately this change from a dormant condition of 

 soil to an active condition is used as an answer to such a vast 

 variety of questions, that when we read so much about these 

 dormant constituents and their change into an active state, 

 we feel inclined to become a little impatient. For instance, 

 if we ask in a question-paper Why farmyard manure is such 

 an excellent manure ? we are told, " Because it changes the 

 dormant constituents into active constituents." We may ask 

 Why autumn cultivation is excellent ? and the answer is, 

 " Because it changes the dormant constituents into active 

 constituents." Or we may ask for the theory of tillage 

 operations, and the theory of all tillage operations appears 

 to be, "that they change the dormant constituents into active 

 constituents." Or we may ask a drainage question, and are 

 told the same thing. 



Now of course we want, if possible, to take both teachers 

 and students out of anything like a narrow groove, and it is 

 for that reason that I think all the other features ou^ht to 



O 



be brought prominently before students, and they should 

 be encouraged to look upon the subject- in a wider manner, 

 and from as great a number of points of view as possible. 



