SCIENCE IN AGRICULTURE. 235 



while be grows old and is unwilling to wait forever. 

 He is able and ready to buy fertilizers, and does buy 

 right and left, without knowing whether his land 

 needs Lime, or Phosphate, or Potash, or something 

 very different from either. Say he purchases $2,000 

 worth of one or more of these fertilizers : it is highly 

 probable that $1,500 might have served him better if 

 invested in due proportion in just what his land most 

 urgently needs ; and I unflinchingly believe that we 

 shall yet have an analysis of soils that will tell him 

 just what fertilizers he ought to apply, and what 

 quantity of each of them. 



Science has already taught us that every load of 

 Hay or Grain drawn from a field abstracts therefrom 

 a considerable quantity of certain minerals say 

 Potash, Lime, Soda, Magnesia, Chlorine, Silica, 

 Phosphorus and that the soil is thereby impover- 

 ished until they be replaced, in some form or other. 

 As no deposit in a bank was ever so large that con- 

 tinual drafts would not ultimately exhaust it, so no 

 soil was ever so rich that taking crop after crop from 

 it annually, yet giving nothing back, would not ren- 

 der it sterile or worthless. Sun and rain and wind 

 will do their part in the work of renovation ; but all 

 of them together cannot restore to the soil the mineral 

 elements whereof each crop takes a portion, and which, 

 being once completely exhausted, can only be replaced 

 at a heavy cost. Science teaches us to foresee and 

 prevent such exhaustion in part, by a rotation of 

 crops, and in part by a constant replacement of the 



