CONTENTS 



INTRODUCTORY 



In the Scientific Study of Soils, Chemical, Physical, and Bio- 

 logical Considerations are involved . . 



CHAPTER I 



THE ORIGIN OF SOILS 



Sedentary Soils, and Soils of Transport Weathering 

 The -Composition of Rock-forming Minerals and their 

 Weathered Products Distinction between Soil and Sub- 

 soil General Classification of Soils . . .6 



CHAPTER II 



THE MECHANICAL ANALYSIS OF SOILS 



Nature of Soil Constituents : Sand, Clay, Chalk, and 

 Humus Methods of Sampling Soils Methods for 

 the Mechanical Analysis of a Soil Interpretation of 

 Results ....... 36 



CHAPTER III 



THE TEXTURE OF THE SOIL 



Meaning of Texture and Conditions by which it is affected 

 Pore Space and Density of Soils Capacity of the Soil 

 for Water Surface Tension and Capillarity Percola- 

 tion and Drainage Hygroscopic Moisture . . 66 

 zi 



