CHAPTER XXIV. 



OTHER FERTILIZING POWERS AND EFFECTS OF CALCAREOUS EARTH. 



WHEN stating the supposed powers, or modes of operation, of 

 calcareous earth, or of the salts of lime generally, as ingredients 

 of soils, by which their presence caused fertility, and their absence 

 or great deficiency maintained barrenness (Chap. VIII.), no power 

 or quality was named which had not been either inferred in ad- 

 vance of any known results of calxing, or observed in natural 

 soils, or otherwise, soon after the commencement of my practical 

 applications. Also, subsequently, in Chap. XIX., when either re- 

 capitulating, or stating for the first time, the results of calxing, 

 none were named (unless incidentally and slightly), which had not 

 been obtained from my own practice, or by personal observation of 

 the practice of intelligent and trustworthy co-labourers in this 

 mode of improvement. There remain to be presented other or 

 greater effects than had been anticipated, or known early from ex- 

 perience ; and also other auxiliary and important causes for such 

 unexpected measure of benefit produced by calcareous manures. 



My own early practice in calxing was mostly on acid soils. The 

 much smaller surface of neutral soils, though also marled, was not 

 observed for the effects through a course of years nor carefully, by 

 experiment, for less time, in but few cases. On such soils, my 

 theory promised no early perceptible benefits ; and late returns 

 could not well be known and estimated, except from large surfaces, 

 as a whole field, or the greater part of a farm. 



But though my high and hilly farm of Coggins had but a small 

 proportion of neutral soil, most of the lower and level lands on the 

 tide-water of James river consisted principally of soil of that kind. 

 These best lands of the lower James (as of all the other tide-waters 

 of Virginia) have evidently been formed by the deposit of alluvial 

 earth, subsequent to the general " upheaving" of the higher-lying 

 and greater body of the surrounding lands from below the bottom 

 of the ancient ocean ; yet long before the present degree of eleva- 

 tion of the general surface had been completed, by the producing 

 geological causes. These ancient alluvial lands are always low, in 

 comparison to the adjacent lands of different and earlier formation; 

 yet so much elevated above the present greatest height of the 

 river, that they have as little of the characteristic defects of " low- 

 ground," as if not of alluvial formation. The common geological 

 origin of these lands, and their common sources of materials, have 

 served to give to them a general uniformity of character and 



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