No. 144.] 177 



All fertile soils contain carbon, alumina, sand, and the various 

 inorganic requirements of plants, and these latter (inorganic re- 

 quirements) are in part freed from their prison houses (the inter- 

 nal portions of particles) by the chemical actions consequent upon 

 the decay of decomposable manures. 



Putrescent manures, those of vegetable and animal origin, as 

 they decompose, assume the gaseous (air like) form, and as gases, 

 are either absorbed by the soil or rise and escape from it into the 

 atmosphere That these decomposable substances do not descend 

 into the soil to any material distance, either when in solution in 

 water or in the gaseous form, is proved by the following facts, 

 well known to all observing farmers : 



If an old barn-yard be dug to a depth of three inches below 

 where the earth has ever been disturbed, the soil will be found to 

 contain no portion of the decomposed matters carried down in so- 

 lution. 



If the brown liquor of a barn-yard be poured on top of a bar- 

 rel of earth, and suffered to filter downward through the mass, 

 the color, odor, and all other matters of a putrescent kind, will 

 be abstracted from the solution by the soil, and water colorless 

 and inodorous, will run from the bottom of the barrel. If the soil 

 had not this property, water from wells could not be drunk, as 

 the soluble portions, consequent upon the decay of vegetation, 

 would all pass down into the wells, and render the water useless 

 as a beverage. 



Now, what is it in the soil that exerts this curious influence *? 

 Simply the carbon and alumina which it contains, as is proved by 

 the following experiment : 



Fill three barrels with pure sand, entirely free from all other 

 substances. Leave one of these barrels of sand in its natural state; 

 to another add five per cent, of finely divided carbon (charcoal), 

 evenly mixed throiigh(ut it; and to the third, five per cent of 

 alumina (common clay). Bore small holes in the bottoms of these 

 barrels, and then pour the brown liquor from the barn yard on top 



[Assembly, No. 144.] L 



