90 THE ANALYSIS OF SOILS. V. 



A slice from this side is then cut with the spade to a 

 suitable depth and about 3 or 4 inches in thickness. 

 This is placed on a clean board to be mixed with the 

 other samples obtained in a similar way from other 

 parts of the field. Finally, these sub-samples are mixed 

 together thoroughly with a trowel or the spade, the 

 sticks, large stones, and roots being removed, and a 

 sample of 2 or 3 kilograms taken for analysis. 



(2) Another, more laborious, plan is to have wooden boxes 



6 inches square and 12 inches in depth to hold the 

 samples. A large hole is then dug at the selected spot 

 and a square prism of soil is left in the centre ; this is 

 carefully trimmed with the spade until the box will just 

 slip over it. The surface of the prism is freed from 

 vegetation, the box is inverted over it, and by means of 

 the spade the box with the column of soil is removed, 

 a label giving particulars of the sample put in, and the 

 lid screwed on. A sample of the soil and subsoil in 

 situ is thus obtained which can be further treated in 

 the laboratory. Several of such samples can be united 

 before a final sample is taken. 



(3) A quicker and in many ways a satisfactory method of 



sampling consists in taking specimens by means of a 

 2 or 2^ inch auger, the borings being placed on a board, 

 a number of them (a dozen or more) from various parts 

 of the area to be examined being mixed together and 

 taken for analysis. A board about 2'6"xl'3 // , with a 

 hole in it just large enough to easily pass the auger, 

 will be found convenient to stand upon and also to 

 receive the borings. 



For general purposes a chemical analysis of the soil is all 

 that is usually done, but great importance is undoubtedly to be 

 attached to its physical properties (e.g., specific gravity, real 

 and apparent, specific heat, conductivity for heat, absorptive 

 power for salts and for water, size of particles, capillarity), 

 and in America and Germany soils are examined with a view 

 to determining these properties and expressing them quantita- 

 tively ; but for methods the student is referred to the waitings 

 of Knop, Kcenig, and Wiley. It is usual to submit the soil to 



