•J8 LOCALITY AND FOHKST VLffKTATlON. 



the degree of division, or the nature of the grain of the soil, 

 must be ascertained. This can be done by shaking a sam- 

 ple, if necessary of each successive layer, with about three 

 times its volume of water in a graduated tube, until all parts 

 are thoroughly separated ; the tube is then placed in a 

 vertical position and watched. As coarse grains settle more 

 quickly than fine grains, it follows that the time occupied 

 compared with the thickness of the deposit indicates the 

 degree of division of the particles. A high degree of division 

 indicates a stiff soil, the presence of coarse grains the 

 reverse, and thus an idea can be formed of the degree of 

 porosity. 



If necessary, the capacity to absorb water, to attract it 

 from the subsoil, to retain it, and the hygroscopicity of the 

 soil can be ascertained by special experiments, l)ut in practical 

 sylviculture they are rarely called for. 



The exact composition of the soil can only be ascertained 

 by means of a chemical analysis. In practice the forester 

 can easily acquire the faculty of distinguishing in a rough 

 and ready manner between the several constituents. He 

 recognises: — Clay by a high degree of cohesion, a fatty 

 feeling, active absorption of water while emitting a clayey 

 smell, slow disintegration in water, slow drying followed by 

 cracking, frequently a grey colour, etc. ; loam by a lesser 

 degree of cohesion than in the case of clay, rougher feeling, 

 quicker disintegration in water, and generally a more reddish 

 colour ; Utuc by active effervescence if treated with an acid, 

 porosity, light whitish to greyish-white colour, which is, how- 

 ever, frequently turned red by iron, a rough but line grained 

 feeling, etc. ; sand by very slight cohesion, grinding between 

 the teeth, or hard grainy feeling, immediate disintegration 

 in water and rapid settling down in it, a light, glossy, shiny, 

 yellowish-white colour, often converted into red by iron, into 

 white by lime, into black by humus ; humns by its porosity 

 and light weight, peculiar smell like that of fresh garden 

 earth, rapid disintegration in water, wliicb remains dark 



