WHAT SCIENCE HAS DONE FOR GARDENING. 15 



commercial fertilizers were given to the agricultural 

 world, and the fraud in the manufacture was eliminated 

 by the analytical skill of the chemist. A few years ago 

 the terms phosphoric acid and potash were known and 

 understood by a few, but now they are common words 

 in the vocabulary of the most ordinary gardener and the 

 most obscure farmer. And yet this is the work of the 

 chemist, and to him only must the gardener render 

 thanks for the great benefits accruing to the land and 

 plant in the use of fertilizers. 



The improvement of the soil by cultivating leguminous 

 plants in order to accumulate nitrogen from the atmos- 

 phere is a well-known fact, but the discovery of the germ 

 principle, by which the plants have the power to extract 

 this nitrogen from the air, was made in the laboratory of 

 a German scientific investigator. Because of this dis- 

 covery it is now possible to successfully cultivate peas, 

 beans, clovers and other similar plants in localities where 

 before the discovery of this germ principle it was next to 

 impossible to secure satisfactory results. 



Science has even stepped in to instruct on the subject 

 of the cultivation of the soil, and much that is now 

 known on this question is due to the investigations con- 

 ducted at the State Experiment Stations under the 

 direction of men with scientific training on such subjects 

 as: (1) Why shallow plowing should be resorted to in the 

 cultivation of certain plants which develop a large system 

 of surface roots; (2) under what conditions deep plowing 

 should be done, and (3) why the land should not be plowed 

 while in a wet condition; (4) the value of rest to the land, 

 and (5) the rotation of crops. 



Most that is known in reference to irrigation and the 

 value it is to those sections of the country where long, 

 dry seasons are common must be credited to scientific 

 research. Irrigation has made it possible to reclaim land 



