NATURAL GROWTHS OP DIFFERENT SOILS. 49 



they remained visible only in a few places, where they had been 

 most abundant. The accuracy of this inference will hereafter be 

 examined. 



The natural growth of the shelly soils (and of those adjacent of 

 similar value) is entirely different from that of the great body of 

 our lands. Whatever tree thrives well on the one, is seldom found 

 on the other class of soils or, if found, it shows plainly, by its 

 imperfect and stunted condition, on how unfriendly a soil it is 

 placed. To the rich river margins are almost entirely confined the 

 black or wild locust, hackberry or sugar-nut tree, and papaw. The 

 locust is with great difficulty eradicated, or the newer growth of it 

 kept under on cultivated lands j and from the remarkable rapidity 

 with which it springs up and increases in size, it forms a serious 

 obstacle to the cultivation of knd on the river banks. Yet on the 

 wood-land only a mile or two from the river, not a locust is to be 

 seen. On shelly soils, pines and broom-grass \Andropogon scopa- 

 rius] cannot thrive, and are rarely able to maintain even the most 

 sickly growth. 



Some may say that these striking differences of growth do not 

 so much show a difference in the constitution of the soils, as in 

 their state of fertility; or that one class of the plants above named 

 delights in rich, and the other in poor land. No plant prefers poor 

 to rich soil or can thrive better on a scarcity of food, than with 

 an abundant supply. Pine, broom-grass, and sheep-sorrel, delight 

 in a class of soils that are generally unproductive but not on 

 account of their poverty; for all these plants show, by the greater 

 or less vigour of their growth, the abundance or scarcity of vegetable 

 matter in the soil. But on this class of soils, no quantity of 

 vegetable manure could make locusts flourish, though they will 

 grow rapidly on a calcareous hill-side, from which all the soil 

 capable of supporting other ordinary plants has been washed away. 



In thus describing and distinguishing soils by their growth, let 

 me not be understood as extending these rules, without exception, 

 to other soils and climates than our own. It is well established 

 that changes of kind in successive growths of timber have occurred 

 in other places, without any known cause; and a difference of 

 climate may elsewhere produce effects, which here would indicate 

 a change of soil. 



Some rare apparent exceptions to the general fertility of shelly 

 lands are found where the proportion of calcareous earth is in great 

 excess. Too much of this ingredient causes even a greater degree 

 of sterility than its total absence. This cause of barrenness is 

 very common in France and England (on chalk soils), and very 

 exlensive tracts are not worth the expense of cultivation, or im- 

 provement. The few small spots that are rendered barren here are 

 seldom (if ever) so affected by the excess of oyster or mussel shells 

 5 



