162 Plowing and Hoeing. [March, 



But another important object in plowing and hoeing, is to bring 

 a fresh and new surface of moist soil to the atmosphere. For 

 every time this is done, the new surface absorbs a fresh portion of 

 ammonia from the atmosphere. Leaving out of view, then, the 

 pulverization of soil, and the destruction of weeds, we see that 

 another object is gained by a frequent stirring of the soil. Plants 

 are thereby furnished with a greater amount of ammonia, from 

 which the nitrogenous compounds in the crop itself are increased. 



We may sura up in a very few words, the most important ob- 

 jects of plowing and hoeing. 



1. The new exposed surface brought up by the plow or hoe, 

 absorbs caloric in a greater proportion than when the same surface 

 is covered M'ith growing vegetables. In the spring the soil is 

 warmed then, by means of the plow. 



2. Plowing and hoeing aids and facilitates the absorption of 

 oxigen from the atmosphere. The protoxide of iron in the soil, 

 becomes a peroxide. 



■!. The peroxide of iron, when freshly formed, is readily decom- 

 posed by the organic matter in the soil. In other words, by this 

 means the organic matter is burnt; by which it becomes an oxid- 

 ized body, and capable of entering into combination with inor- 

 ganic elements. 



4. Water is decomposed also by the peroxide, by which means 

 hydrogen is liberated; and which being in a nascent state, is dis- 

 posed to enter into combination with nitrogen. This gives the 

 soil ammonia, and of course indicates the method by which nitro- 

 genous compounds are generated in the living vegetable. 



5. Every fresh moist surface absorbs of itself the floating free 

 ammonia of the atmosphere, so that a double source of this im- 

 portant element is provided for in the chemistry of nature. 



Remarks. If the foregoing are not the only ends which are 

 accomplished by plowing and sow^ing, it is plain that these 

 must be among the most important. 



W^e see from the foregoing view of the subject, that the analy- 

 sis of soils is an important object, were it for^the single purpose 

 of determining the amount of iron in the soil, and the states in 

 which it exists. And we see too that those writers upon agricul- 

 ture, the editors of our journals, have only a faint view of the 

 chemistry of nature, when they have undertaken to cry down che- 

 mical investigations of the soil. 



Correct and productive, or profitable husbandry, must rest upon 

 a knowledge of the physical and chemical laws of nature. A 

 manufacturer might just as well think of extracting profits from 

 the old mode of spinning wool and cotton, as the husbandman to 

 obtain the largest profits from a farm by dint of labor alone, un- 

 assisted by the lights of modern science and modern improvements 

 in the implements of husbandry. 



