^4 CALCAREOUS MANURES— THEORY. 



dence of the remarkable and novel fact of the general absence of calca- 

 reous earth — and the information thence derived will be used to sustain 

 the following steps of my argument. 



All the examinations of soils in this chapter concur in opposing the ge- 

 neral application of the proposition that the deficiency of calcareous earth 

 is the cause of the sterility of our soils. And having stated the objection in 

 all its force, I shall now proceed to inquire into its causes, and endeavor to 

 dispel its apparent opposition to my doctrine. 



W, CHAPTER Vn. 



PROOFS OF THE EXISTENCE OP ACID AND NEUTRAL SOILS. 



Proposition 2— continued. 



Sufficient evidence has been adduced to prove that many of our most 

 fertile and valuable soils are destitute of calcareous earth. But it does not 

 necessarily follow that such has always been their composition ; or that 

 they may not now contain lime combined with some other acid than the 

 carbonic. That this is really the case, I shall now offer proofs to establish ; 

 and not only maintain this position with regard to those valuable soils, but 

 shall contend that lime, in some proportion, combined with vegetable add, is 

 present in every soil capable of supporting vegetation. 



But while I shall endeavor to maintain these positions, without asking or 

 even admitting any exception, let me not be understood as asserting that 

 the original ingredient of calcareous earth was always the sole cause of 

 the fertility of any particular soil, or that a knowledge of the proportion 

 contained, would serve to measure the capacity of the soil for improvement. 

 Calcareous soils, not differing materially in qualities or value, often exhibit 

 a remarkable difference in their respective proportions of calcareous earth ; 

 so that it would seem that a small quantity, aided by some other unknown 

 agent, or perhaps by time, may give as much capacity for improvement, 

 and ultimately produce as much fertility, as ten times that proportion, under 

 other circumstances. 



In all naturally poor soils, producing freely pine and whortleberry in . 

 their virgin state, and sheep sorrel after cultivation, I suppose to have been 

 formed some vegetable acid, which, after taking up whatever small quantity 

 of lime might have been present, still remains in excess in the Soil, and 

 nourishes in the highest degree the plants named above, but is a poison to 

 all useful crops ; and effectually prevents such soils becoming rich, by 

 either natural or artificial applications of putrescent manures. 



In a neutral soil, 1 suppose calcareous earth to have been sufficiently 

 abundant at some former time to produce a high degree of fertility— but 

 that it has been decomposed, and the lime taken up, by the gradual forma- 

 tion of vegetable acid, until the lime and the acid neutralize and balance 

 each other, leaving no considerable excess of either ; and that such are all 

 our fertile soils which are not now calcareous. 



These suppositions remain to be proved, in all their parts. 



No opinion has been yet advanced that is less supported by good 

 authority, or to which more general opposition may be expected, than that 

 which supposes the existence of acid soils. The term sour soil is frequently 

 used by farmers, but in so loose a manner as to deserve no consideration. 

 It has been thus applied to any cold and ungrateful land, without intending 



