ANALYSIS OF SOILS. 235 



&quot; Now, the results of the analysis give a sufficient account of 

 the failure of the sainfoin.&quot; [But it seems it can be cultivated 

 upon it two or three years in succession.] &quot; The soil contains 

 one per cent, of sulphate of the protoxide of iron, (green vitriol 

 of commerce,) a salt which exerts a poisonous action upon plants. 

 Lime is not present in quantity sufficient to decompose this salt. 

 Hence it is that sainfoin will not thrive in this soil, nor indeed 

 lucern, or any other of the plants with deep roots. The evil 

 cannot be obviated by any method sufficiently economical for 

 the farmer, because the soil cannot be mixed with lime at a 

 depth of five or six feet.&quot; [It requires some courage for a man 

 even to think of such a thing.] &quot; For many years, experiments 

 have been made in vain, in order to adopt this soil for sainfoin 

 and lucern, and much expense incurred, which would all have 

 been saved, had the soil been previously analyzed. This ex 

 ample affords a most convincing proof of the importance of 

 chemical knowledge to an agriculturist.&quot; * 



Now, I think the strong impression which will be upon every 

 practical man s mind, in looking at these analyses, will be, the 

 utter impossibility of meeting the cases, arid of adapting the cul 

 tivation and manuring with any very exact reference to the 

 chemical condition of the soil ; that is, of prescribing for the 

 patient. I admit that the application of chemical analyses or 

 tests to the soil may be of very great importance in detecting 

 the existence of any substance, as in the latter case for example, 

 which is poisonous to vegetation ; though even here, the exist 

 ence of the evil itself, and the remedy, are left somewhat in 

 uncertainty. I believe it may be of great utility in determining 

 the general and predominant characteristics of a soil ; but with 

 great respect for science, and for the labors of those men who, 

 by their distinguished attainments, have conferred the highest 

 benefits upon the community, I can come to no other conclusion 

 than that any expectation of adapting our cultivation, upon any 

 extended scale, to these minute diversities of soil, is illusory; 

 and that the most illustrious chemist living may be challenged 

 in vain to prescribe any practicable culture adapted to meet, with 



* These examples of analyses of soils are by Sprengel, and taken from Liebig s 

 Agricultural Chemistry, from the chapter on the Chemical Constituents of Soils, 

 p. 208, 3d American edition. 



