194 LECTURES. 



and saline manures, such as guano, salt, plaster, lime, &c, experiment 

 with them repeatedly and accurately on the small scale, so as to learn what 

 the crops say about their value. Where phosphates have been heavily 

 applied, it is probable that ammonia or nitrogenous manures, or per- 

 haps lime or potash, may next exert the most beneficial action, and 

 vice versa. Be sure of enough, not only as regards the quantities, but 

 also the kinds of matters applied. 



But our subject requires treatment which only a volume can give 

 space for. The recent progress of knowledge, thanks to the scientific 

 farmers and agricultural philosophers of England, Germany, and 

 France, demands a series of chapters on manures that are as yet 

 unwritten, but, when rightly produced, will be alike novel, interesting, 

 and useful to the true American farmer, who cultivates with equal 

 assiduity the "soil and the mind." 



