APPENDIX B. 



sole, and whether a single or a double team will generally be needed to 

 cultivate it properly. Also whether stock can be allowed to pasture the 

 land soon after rain. Comparison with the known land of neighbors 

 will also thus become easy, and in a measure the crops best adapted to 

 the physical qualities of the soil, subsoil and substrata, taking into 

 account their respective depths, will at once be at least approximately 

 determined. The presence of coarse and fine sand in greater or less 

 amounts will also be thus readily ascertained, allowing estimates of the 

 percolative properties ; the latter can, of course, be more practically 

 tested in the field, in the manner described in chapter 13, page 242. 



A more definite estimate of the amount and kind of sand present in 

 the soil materials can be obtained by washing the kneaded sample into 

 a tumbler, and allowing a thin stream of water to flow into it from a 

 faucet while gently stirring the turbid water. The clay, together with 

 the finest silts, will thus be carried off over the rim of the glass, and 

 sand of any desired degree of fineness, according to the strength of the 

 stream of water used, will be left behind. The kind and amount of 

 these sandy materials can then be estimated, or definitely ascertained 

 by weighing or measuring. 



This will, generally speaking, be as far as the uninstructed farmer can 

 readily go ; but these simple operations will give him an insight into the 

 nature of his soil and subsoil that will enable him to avoid a great many 

 costly mistakes. 



RECOGNITION AND MEANING OF THE SEVERAL SOIL MINERALS. 1 



Those somewhat familiar with scientific methods and operations, and 

 supplied with pocket lens or microscope, can profitably go much farther 

 towards the definite ascertainment of the permanent cultural value of 

 the land, by the study of the minerals of which the sand is composed, 

 and which as a rule represent those from which the entire soil has been 

 formed ; therefore indicate in a general manner its chemical compo- 

 sition. Such examinations are specially feasible and important when 

 soils are not far removed from their parent rocks, as in most of the 

 arid region, and in the states north of the Ohio. In the Southwestern 

 states, in the coastal plain of the Gulf of Mexico, the original soil 

 minerals have usually been too far decomposed to admit of definite 

 identification. Sand is there as a rule made up of quartz grains of 

 many varieties, with only an occasional tourmaline and pyroxene. 



Among the prominent soil minerals, quartz is almost always recogniz- 

 1 For more details see chapters 3 and 4. 



