PUTTING THE SOIL IN CONDITION 113 



scrutiny discovers signs and symptoms upon 

 which he bases his judgment as to the disease 

 that has made us sick, and the remedy to be ap- 

 plied. 



The same principle must be applied to the 

 diagnosis of our soils which have lost their crop 

 producing power, to ascertain the nature and ex- 

 tent of its ills and the remedy to be applied. 



The skilled physician knows the very structure 

 of the human body and the tissues that make it 

 up. He knows its origin, the conditions that 

 enhance or retard its growth, and the food needed 

 to sustain it. It would therefore seem that he 

 who seeks to cure the diseases of our worn and 

 worn-out soils must possess some skill as a "soil 

 doctor"; that he should know the very origin of 

 soil; that soil is that upper stratum of the earth 's 

 surface composed of substances which furnish 

 food for plant growth ; that soil was produced or 

 made up by the wearing down or decay and dis- 

 solution of rocks, the washing of sand and decay 

 of vegetable or organic matter; and he too must 

 know the food it needs to make it fertile. 



The writer does not believe that in order to be- 

 come a "soil doctor" it is necessary that one 

 should become skilled in the science of chemistry 

 or other sciences. Bather he should become the 

 student of Nature, sit at her feet and observe 

 her ways. 



While the study of the sciences may teach us 

 that the three elements of potash, phosphorus 

 and nitrogen are necessary to make fertile soils; 

 that these elements are vitally necessary because 

 they increase the quality, fruitfulness, early ma- 



