NATURE OF SOIL 



29 



Phosphoric acid is P 2 5 . Common table salt is Nad (sodium 

 and chlorin). 

 Following are the formulas for various common substances : 



Acetic acid C 2 H 4 O 2 



Ammonia NH 3 



Aniline NH 2 (C 6 H 5 ) 



Arsenious oxid .... As 2 O 3 



Carbon dioxid . . . . CO 2 



Carbonic oxid .... CO 



Chloroform CHC1 3 



Ferric oxid (iron rust) . . Fe 2 O 3 



Ferrous oxid FeO 



Hydrochloric acid . . . HCl 



Mercuric oxid .... HgO 



Nitrate of soda .... NaNO 3 



Nitric acid HNO 3 



Nitric oxid . . . . 



Nitric peroci 1 . . . 



Nitrous oxid . . . . 



Saltpetre . . . . . 



Starch . . . . . . 



Strychnine . 



Sugar, cane . . . . 



Sugar, grape or glucose 



Sulfate of potash . . . 

 Sulfuretted hydro^n . 



Sulfuric acid . . . . 



Sulfuric oxid . . . . 



Sulfurous oxid . . . 



NO 



NO 2 



N 2 



KN0 3 



C 6 H 10 O 5 



C 21 H 22 N 2 O 2 



C 12 H 22 O n 



6 12 

 K 2 S0 4 

 H 2 S 



so a 



The Soil 



The soil, as the farmer understands it, is the soft tillable covering or 

 epidermis of the earth. It is derived primarily from disintegrated rock, 

 but all productive soils contain organic remains, or materials derived 

 directly from these remains. Some soils, as those in swamps, are very 

 largely organic. 



Classification of soils in respect to origin (Merrill) 



Sedentary 



( Residual deposits 

 I Cumulose deposits .1 

 Colluvial deposits 



Transported 



f Residuary gravels, sands, clays, wacke, 



laterite, terra rossa, etc. 

 Feat, muck and swamp or palludal 



soils, in part. 

 j Talus and cliff debris, material of 



avalancHes. 



Alluvial deposits, i Modern alluvium, marsh and swamp 

 including the J deposits, estuarian clays. Loess and 

 aqueo-glacial . [ adobe in part. 



J Wind-blown material, sand-dunes. 

 J3olian deposits . Adobe and loess in part. 



t Morainal material, either lateral, ter- 



Glacial deposits . J minal, or ground moraines, drum- 

 lins, etc. 



NAME 

 1. Gravel 



Coarse sand 

 Medium sand 

 Fine sand . . 

 Very fine sand 

 Silt . . . . 

 Clay . . . . 



Classification of soil constituents (U. S. Dept. Agric.) 



SIZE OP PARTICLES 

 (diameters in millimeters) 



2.0 to 1.0 



1.0 to 0.5 



0.5 to 0.25 



0.25 to 0.1 



0.1 to 0.05 



0.05 to 0.005 



0.005 to 0.0000 



