IN'TRODUCTION. XIX 



root when in certain quantities. The advantages of 

 phosphoric acid have been pointed out, as well as the 

 mistake in using non-soluble phosphates, as Liebig 

 and several others have done for years. 



Potassic fertilizers, however successful they have, 

 been in Germany, the author considers that their use 

 should be to a certain extent restricted, as they do not 

 facihtate the formation of the sugar, and few advan- 

 tages can be derived from their employment. The cal- 

 careous fertilizers, as shown, are of the highest im- 

 portance when the soil does not contain sufficient lime, 

 these facilitating the action of the acids of the stratum 

 below. To make even more evident the advantages 

 of the chemical fertilizer over barnyard manure, com- 

 parative experiments have been given which clearly 

 show the truth of this apparently mere hypothesis. 

 Knowing these facts, what manures can be recom- 

 mended? Evidently these vary according to the 

 localities ; and the author has endeavored to give the 

 various methods of ascertaining the most suitable for 

 a given soil, these being principally based upon expe- 

 rience. Besides these, various fertilizers are sold, and 

 highly recommended for beet culture, the composition 

 of which has been thought of interest. 



The advantages of a small or large seed have been 

 carefully studied, and the importance of each farmer 

 growing his own has been pointed out. These seeds 

 after being placed in the soil germinate under the in- 

 fluence of certain agents. Touching the advantages 



