190 



THE SYSTEM OF FARM-YARD MANURING. 



but because they have resulted in fully estabhshing a 

 number of facts which will for all time to come retain 

 their validity as safe bases for scientific conclusions. 

 Science owes the deepest gratitude to the excellent pro- 

 pounder of these inquiries, and to the worthy men who so 

 zealously performed their task ; the only thing to be 

 regretted is, that the experiments upon unmanured plots 

 were not carried out in all cases. 



It is evident that the action of farm-yard manure upon 

 a field can be properly estimated only if it is known before- 

 hand what amount of produce the field will give without 

 any manure : and first of all we shall consider the crops 

 produced on five fields in five different parts of Saxony, 

 in the four-year rotation above mentioned. 



These results lead to the following considerations. 



The term unmanured, as applied to these fields, is 

 meant to designate the condition in which they were left 

 at the end of a rotation by a succession of crops. 



These fields had been manured at the beginning of the 

 rotation ; and had they been manured afresh, tliey would 



