A WORD ABOUT MANURES. 291 



every careful farmer, there is another class of manures call- 

 ed "artificial," and these can be procured at any place by a 

 sufficient outlay. But they are costly, and it requires a sci- 

 entific acquaintance with their properties, before the ordina- 

 ry farmer will have the courage to invest in them. In other 

 words, he must be able to see why and how his money will 

 be returned' with interest. 



In orcler to properly understand the requirements of 

 plants^ it is essential the action of the different manures" 

 should be known, together with an approximate knowledge 

 of the constituents of the soil. Soils are the result of the 

 degradation, or breaking down, from various causes, of 

 rocks. Through the great convulsions of nature, this tri- 

 turated dust is mingled together, so that every species of 

 rock formation is represented in every handful of clay. 

 Were this not the case, we would have over limestone rocks a 

 great mass of unproductive pulverized carbonate of lime; or 

 over granite, we would see nothing but the sparkling atoms 

 of quartz and mica, and over each stratum there would be 

 the constituents of that rock, and hence no vegetation would 

 charm the eye or delight the heart, to say nothing of our 

 digestive wants. Through the agency of perfectly natural 

 causes, (water principally), the soils have been intimately 

 mingled. By this wise provision vegetation, in every spot in 

 the world, finds some elements necessary to its existence. 

 But it sometimes happens, that there is a deficiency of 

 some of the elements, and again that there is a surplus. In 

 the great alluvial swamps decayed vegetable matters exist 

 to such an extent that some cereals do not thrive well, 

 and oh the other hand, on the steep mountain sides, by the 

 action of washing rains, this matter has been carried oft. 

 Again, in many sections, the fertile matters have been ex- 

 hausted, so nearly so, that the products of the soil cease to 

 be remunerative. It is the province of scientific agricul- 

 ture to point out these deficiencies and direct the remedy. 



The soil originally consisted simply of the debris of the 



