102 



LIME IN ASHES OF VARIOUS PLANTS. 



1849.] 



Additional and practical proofs of all these powers of calcareous 

 earth will be furnished, when its use and effects as manure will be 

 stated. I am persuaded, however, that enough has already been 

 said both to establish and account for the different capacities of 

 soils for improvement by putrescent manures. If the power of 

 fixing manures in soils has been correctly ascribed to calcareous 

 earth, that alone is enough to show that soils containing that in- 

 gredient, in proper quantities, must become rich; and that alumi- 

 nous and silicious earths mixed in any proportions, and even with 

 vegetable or other putrescent matter added, can never form other 

 than a sterile soil.* 



[* The several peculiar or stronger powers for increasing fertility and 

 production ascribed above to calcareous earth in soil, are {hose which were 

 presented to my mind either in advance of all practical applications of the 

 earth as manure, or otherwise were the results of actual observation 

 within a few years after the commencement. The chemical laws and 

 agencies were of course gathered from books. The confirmatory facts 

 were mostly found in my observation of the characters of natural soils, and 

 in the earliest results of my calcareous manurings. It is not necessary 

 here, and would scarcely be proper, to adduce other powers of calcareous 

 manures, learned from much later practical results, or which have since 

 been presented by later and much more scientific investigators. Sundry 

 other useful and some very important agencies of calcareous earth in soils 

 may be seen in the "Lectures on the Applications of Chemistry and 

 Geology to Agriculture," by J. F. W. Johnston. It is gratifying to me, 

 that this author in most respects sustains my doctrine ; though in some 

 points we are entirely opposed. These differences, as well as the most im- 



