SCIENCE AND PRACTICE OF FEEDING 65 



Magnesia 10.2 parts 



Iron oxide 3.7 " 



Phosphoric acid 19-5 " 



Silica ! 6.0 " 



Chlorine 3.0 " 



Sulphuric acid 4.7 " 



If the food supplied to the plants were 

 based upon a literal assumption of the facts 

 as demonstrated by the analysis, we should 

 probably be obliged to go to the druggist 

 to have it prepared. The practical experience 

 of many growers for years, however, has 

 demonstrated the fact that soils generally 

 contain enough of most of the elements 

 necessary to the development of all forms 

 of plant life. The soils found in practically 

 all parts of the United States, with the 

 exception of the Western deserts and alkali 

 regions, contain more or less of all the ele- 

 ments in the structure of the chrysanthe- 

 mum. Generally there is an insufficient 

 supply of some of the elements for the 

 highest development of the plants; conse- 

 quently we must supply the deficiency. 



ELEMENTS OF PLANT FOOD 



As it is practically impossible for us to 

 know positively how much of the different 



