CALCAREOUS EARTH, 23 



become carbonated), all these are the same chemical substance ; but 

 none of these names would serve, because each would be supposed to 

 refer to such certain form or appearance of calcareous earth as they 

 usually express. If I could hope to revive an obsolete term, and, 

 with some modification, establish its use for this purpose, I would 

 call this earth calx-^ and from it derive calxing, to signify the 

 application of calcareous earth, in any form, as manure. A general 

 and definite term for this operation is much wanting. Liming, 

 marling, applying drawn ashes, or the rubbish of old buildings, 

 chalk, or limestone gravel, all these operations are in part, and 

 some of them entirely, that manuring which I would thus call 

 calxing. But because their names are different, so are their effects 

 generally considered not only in those respects where differences 

 really exist, but in those where they are precisely alike. 



Calcareous earth, in the agricultural sense here assumed (calx, 

 or carbonate of lime), has almost no existence as an ingredient of 

 soil throughout all the great Atlantic slope of the United States 

 north of Florida. Nor has it any existence, separate from soil, 

 unless as lime-stone rock and travertine in the mountain region, 

 and subterranean beds of fossil shells in the tide-water lands. In 

 England, France, and some other parts of Europe, this earth occurs 

 as chalk, in beds of great thickness and vast extent of surface. The 

 whiteness of chalk repels the rays of the sun, and its open texture 

 permits water to sink through almost as easily as through sand. 

 Thus calcareous earth alone, or when constituting the bulk of a 

 soil, is remarkable for possessing some of the worst qualities of 

 both sand and clay. 



But though the true chalk, which is so widely spread in Europe, 

 does not exist in North America, there are very extensive regions 

 of this continent of which the soils are composed in part, and their 

 subsoils mainly, of calcareous earth, and which may be considered 

 as chalk soils and subsoils in an agricultural, though not a geo- 

 logical sense. Such are most of the a prairie" lands of Alabama, 

 Mississippi, and Arkansas } and (as I infer from analogy) of Texas, 

 and of the vast prairie region west of the Mississippi River. The 

 " everglades" of Florida, as I infer, and the nearest sea islands 

 also, are of like constitution. The subsoil and inferior layers, 

 known in many cases to be several hundred feet thick, are like an 

 impure chalk, composed principally of carbonate of lime (of which 

 there is a proportion from 70 to more than 80 per cent.), inter- 

 mixed intimately, or combined, with fine clay, which constitutes the 

 small remaining part. This great formation of impure calcareous 

 earth may be considered as either a very rich marl, or a poor chalk ; 

 and similar to true chalk in every relation to agriculture, except (in 

 consequence of its argillaceous admixture) in being, in most cases, 

 as much impervious to water as true chalk is the reverse. 



