WHITE BUELEY TOBACCO. 337 



try, except in the principal blue grass counties, is very 

 much broken, and nearly every member of the Lower 

 Silurian formation is exposed at one or more places in 

 the district. This gives within limits a considerable 

 variation in the composition of the soil, but all of it is 

 made fertile by the presence of the carbonate and phos- 

 phate of lime. The principal tree growth on the best 

 tobacco soils is hickory, white oak, jtulip tree, beech, 

 walnut, hackberry, black locust and ash. All this 

 growth indicates a very fruitful soil. Where the white 

 oak is the prevailing growtfi the soil is called "oak 

 soil." The soils in every part of the district are exceed- 

 ingly durable, and where apparently exhausted, if they 

 are abandoned for a few years, fresh plant food will be 

 supplied by the disintegration of the shaly beds and 

 the soft limestones that underlie them. Many of these 

 limestones contain such a large percentage of phos- 

 phoric acid as even to make them, when pulverized, val- 

 uable as a fertilizer. 



The great unevenness of the surface of the country 

 maket tillage difficult. The slopes of the hills, except 

 when kept in grass, soon become scarified with unsightly 

 gullies. Clean culture, such as tobacco requires, soon 

 makes the land unproductive, not, as many suppose, by 

 the amount of fertilizing material extracted from the 

 soil by that crop, but because of the rapidity and ease 

 with which the soil is carried from the hillsides to the 

 valleys. However, the region is fortunate in having a 

 subsoil and rocky strata beneath, which hold in store a 

 large amount of unexpended plant food, which is una- 

 vailable until it has been liberated by the crumbling of 

 these underclays and rocky beds through the effects of 

 weathering. Unlike almost any other region not 

 alluvial, the fertility of the soil is renewed by time, as 

 interest gathers upon a fixed capital. 



While a few planters prefer the old lands, and 



