74 PROOFS OP NEUTRAL AND ACID SOILS, 



covered and filled to excess with leaves and other rotted and rotting 

 vegetable matters. Can a heavier vegetable manuring be desired ? 

 And as this completely rots during cultivation, must it not offer to 

 the growing plants as abundant a supply of food as they can re- 

 quire ? Yet the best product obtained may be from ten to fifteen 

 bushels of corn, or five or six of wheat, soon to come down to half 

 f those quantities. If the noxious quality which causes such injury 

 is an acid, it is as certain as any chemical truth whatever, that it 

 will be neutralized, and its powers destroyed, by applying enough 

 . of calcareous earth to the soil ; and precisely such effects are found 

 wherever that remedy is tried. On land thus relieved of this un- 

 ceasing annoyance, the young plants of corn no longer appear of a 

 pale and sickly green, approaching to yellow, but take immediately 

 a deep healthy colour, by which they may readily be distinguished 

 from any on adjoining ground, left in its former state, before there 

 is any perceptible difference in the size of the plants. The crop 

 will produce fifty to one hundred per cent, more, the first year, be- 

 fore its supply of food can possibly have been increased; and the 

 / soil is soon found not only clear of sorrel, but absolutely incapable 

 of producing it. I have anticipated these effects of calcareous ma- 

 nures, before furnishing the evidence ; but they will hereafter be 

 established by facts beyond contradiction. 



The truth of the existence of either acid or neutral soils depends 

 on the existence of the other ; and to prove either, will necessarily 

 establish both. If acid exists in soils, then whenever it meets with 

 calcareous earth, the two substances must combine with and neu- 

 tralize each other, so far as their proportions are properly adjusted. 

 On the other hand, if I can show that compounds of lime and vege- 

 table acid are present in most soils, it follows inevitably that nature 

 has provided means by which soils can generally obtain this acid ; 

 and if the amount formed can balance the lime, the operation of 

 the same causes can exceed that quantity, and leave an excess of 

 free acid. From these premises will be deduced the following 

 proofs. 



5th. It has been stated (page 57) that the process recommended 

 by chemists for finding the calcareous earth in soils was unfit for 

 that purpose, because some precipitate was always obtained, even 

 when no calcareous earth or carbonate of lime was present. Fre- 

 quent trials have shown me that this precipitate is considerably 

 more abundant from good soils than bad. The substance thus ob- 

 tained from rich soils by solution and precipitation, in every case 

 that I have tried, contains some carbonate of lime, although the 

 soil from which it was derived had none. The alkaline liquor from 

 which the precipitate has been separated, we are told by Davy, will, 

 after boiling, let fall the carbonate of magnesia, if any had been in 

 the soil ; but when any notable deposit is thus obtained^ it will 



