34 CALCAREOUS MANURES— THEORY. 



ments may be found of some particular soils being considered of that cha- 

 racter. These statements, even if presented by the authors of general 

 treatises, would only seem to present exceptions to their general rule of the 

 almost universal diffusion of calcareous eartii in soils. But, so far as I know, 

 no such exceptions are named in the descriptions of soils in any general 

 treatise, and therefore have not the slightest influence in contradicting or mo- 

 difying their testimony on this subject. It is in the description of soils of 

 particular farms, or districts, that some such statements are made; and 

 even if no such examples had been mentioned, they would not have been 

 needed to prove the existence, in Europe, of some soils, like most of ours, 

 destitute of calcareous earth. These facts do not oppose my argument. I 

 have not asserted, (nor believed, since I have endeavored to investigate this 

 subject,) that there were not soils in Europe, and perhaps many extensive 

 districts, containing no calcareous earth. My argument merely maintains, 

 that these facts would not be inferred, but the contrary, by any general and 

 cursory reader of the agricultural treatises of Europe with which we are 

 best acquainted. It has not been my purpose to inquire as to the existence, 

 or extent, of soils of this kind in Europe. But judging from the indirect 

 testimony furnished by accounts of the mineral and vegetable productions, 

 in general descriptions of different countries, I would infer that soils 

 having no calcareous earth were often found in Scotland and the northern 

 part of Germany, and that they were comparatively rare in England and 

 France. 



With my early impressions of the nature and composition of soils, de- 

 rived in like manner from the general descriptions given in books, it was 

 with surprise, and some distrust, that, when first attempting to analyze soils, 

 in 1817, I found most of the specimens entirely destitute of calcareous 

 earth. The trials were repeated with care and accuracy, on soils from 

 various places, until I felt authorized to assert, without fear of contradiction, 

 that no naturally poor soil, below the falls of the rivers, contains the small- 

 est proportion of calcareous earth. Nor do I believe that any exception to 

 this peculiarity of constitution can be found in any poor soil above the 

 falls ; but though these soils are far more extensive and important in other re- 

 spects, they are beyond the district within the limits of which I propose to 

 confine my investigation. 



These results are highly important, whether considered merely as serving 

 to establish my proposition, or as showing a radical difference between 

 most of our soils, and those of the best cultivated parts of Europe. Putting 

 aside my argument to establish a particular theory of improvement, the 

 ascertained fact of the universal absence of calcareous earth in our poor 

 soils leads to this conclusion, that profitable as calcareous manures have 

 been found to be in countries where the soils are generally calcareous in 

 some degree, they must be far more so on our soils that are quite destitute 

 of that necessary earth. 



CHAPTER V. 



RESULTS OF THE CHEMICAL EXAMINATIONS OP VARIOUS SOILS. 



Proposition 2. — continued. 



The certainty of any results of chemical analysis would be doubted by 

 most persons who have paid no attention to the means employed for such 

 operations ; and their incredulity will be the more excusable, when such 



