AND ITS DISEASE. 57 



at the planting; however old they may be if not 

 exhausted by overcropping ; for the continual stir- 

 ring of the soil as in the peach orchard and the 

 turning in yearly with the plow all vegetable 

 growth, that may be made through the growing 

 season, and the fallen foliage of the trees in the fall; 

 together with the exposure of the soil to the de- 

 composing actions of rains and frost arid other 

 atmospheric influences, make soluble that which 

 was before insoluble for the support of plants. 

 From rock and stone and pebble ^nd grains of sand, 

 down even below a microscopic atom is developed 

 this important agent, potash, which plays its in- 

 comprehensible role in the support of vegetable 

 and animal life. All these elements are at work 

 in their proper seasons, furnishing lime, potash 

 and other alkalies to the soil, the same as we ob- 

 serve in Virginia for the past century, furnishing 

 slowly but surely a returning supply of plant food 

 to be husbanded, it is to be hoped, more carefully 

 for the present and succeeding generations. 



We may assume that the peach, apple and pear 

 contained in their first introduction into the coun- 

 try the same quantities and relative proportion of 

 ingredients in their composition that they now do, 

 and that no complaint was then made in the North 

 that the soil had become exhausted of its potash 

 and lime ; nor is there any complaint now in the 

 South where the orchards thrive and produce from 

 fifty to sixty years. The shortened life and failure 



