SUMMARY OF CHAPTERS. 



1. ORIGIN AND FORMATION OF SOILS. 



Introduction. 



Chapter I. Physical Processes of Soil Formation. 



" II. Chemical Processes of Soil Formation. 



" III. Chief Soil-forming Minerals. 



" IV. The Various Rocks as Soil-Formers. 



" V. Minor Mineral Ingredients of Soils. Mineral Fertilizers. 



Minerals Injurious to Agriculture. 



2. PHYSICS OF SOILS. 



Chapter VI. Physical Composition of Soils. 



" VII. Density, Pore Space, and Volume-Weight of Soils. 



" VIII. Soil and Subsoil ; Causes and Processes of Differen- 



tiation ; Humus. 



" IX. Soil and Subsoil ; Organisms Influencing Soil-Con- 



ditions. Bacteria. 



" X. Soil and Subsoil in their Relations to Vegetation. 



" XI. Water of Soils ; Hygroscopic and Capillary Moisture. 



" XII. Water of Soils ; Surface, Hydrostatic, and Ground- 



water ; Percolation. 



" XIII. Water of Soils ; Conservation and Regulation of Soil 



Moisture. Irrigation. 



XIV. Absorption by Soils of Solids from Solutions. Absorp- 

 tion of Gases. The Air of Soils. 



" XV. Colors of Soils. 



" XVI. Climate. 



" XVII. Relations of Soils and Plant-Growth to Heat. 



3. CHEMISTRY OF SOILS. 



Chapter XVIII. Physico-Chemical Investigation of Soils in Relation 



to Crop Production. 

 XIX. Analysis of Virgin Soils by Extraction with Strong 



Acids, and its Interpretation. 

 XX. Soils of Arid and Humid Regions. 

 XXI. Soils of Arid and Humid Regions continued. 

 XXII. Alkali Soils, their Nature and Composition. 

 XXIII. Utilization and Reclamation of Alkali Lands. 



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