1847.] Effect of Plants on the JYutriment of Soils. 143 



heaps of the fragments of these rocks might be turned to good ac- 

 count as tertilizers, provided a disintegration could be affected. 

 In many instances, there is not the slightest (hfficulty in bringing 

 them to a pulverulent mass. Where they resist decomposition, 

 piles of the debris, if heated, would crumble more speedily to pow- 

 der. If they were coarsely pulverized, the mechanical effects in 

 many cases would be important, especially on the argillaceous 

 soils; and they would slowly yield up their potash, phosphates, 

 magnesia and lime, to supply the annual waste to which the soil 

 is subjected by cropping. Rocks which contain sulphuret of iron 

 undergo a rapid disintegration, and afterwards a thorough decom- 

 position. In these rocks are contained, in all cases, valuable fer- 

 tilizers, which are available by the aid of quicklime. From them 

 a large amount of gypsum may be obtained by means of the lime, 

 in addition to the other soluble matters which the rock may con- 

 tain. 



13, In conclusion, I feel justified in saying that the available 

 means within the reach of the farmers of New York are much 

 greater than has been supposed. The gypsum, marls, limestones, 

 peat, and broken down shales, either gypseous or calcareous, 

 miy be employed at a reasonable expense, not only to sustain the 

 soil in its present state of fertility, but to increase considerably 

 its productiveness." 



THE EFFECT OF PLANTS ON THE DISTRIBUTION OF 

 NUTRIMENT IN SOILS. 



The uhimate effects of plants on the nutriment in soil, depends 

 upon circumstances. The immediate effects in all cases of grow- 

 ing plants, is the same. The latter is to bring from below the 

 food, and convert it into organized matter. When this is done 

 in the case of weeds, it operates beneficially, provided they are 

 saved and allowed to rot in heaps, and afterwards redistributed 

 over the surface; or which amounts to the same thing, either lie 

 in the position where they grew, and there decay. By this ope- 

 ration they have brought a quantity of food to the surface, which 

 is not taken away. Weeds do not then impoverish soil, though 

 they divide the food of the store-house, the earth, with more valu- 

 able plants, as grains. Trees, which survive for centuries, ope- 

 rate somewhat differently. They take up the food and store it 

 up for their use, or rather convert it into wood, and this matter 

 may be considered as being lost to the soil, inasmuch as they are 

 finally removed from the fields. It is true a large portion is re- 



