CLIMATE AND SOIL 35 



It is owing to the great soil improving qualities of the 

 beech that the woodman will be often recommended to grow 

 this tree together with the more valuable species. Although 

 in many places beech timber is not of very great value, yet 

 a place should be found for it in every wood, as other and 

 more valuable species will grow better in mixture with beech 

 than without it, as they get the advantage of the humus and 

 improved soil, while, in addition, they grow cleaner timber 

 owing to the heavy cover of the beech, which kills ofif the 

 branches. This is easily observed in any oak and beech 

 wood ; where the oak has been grown densely surrounded 

 with beech it will almost always be found to be taller, cleaner, 

 and of better shape than when it has been grown pure ; if 

 a wood of pure oak has reached the age of about a hundred 

 years the soil will almost always be found to have deteriorated 

 under it, while humus is conspicuous by its absence ; the oaks 

 will also almost certainly be very branched. 



A good rough method of determining the quality of the 

 soil is to dig holes here and there throughout the area to 

 a depth of four feet if rock is not found at a less depth. One 

 side should be made vertical, and on this the thickness of 

 humus and of the different layers can be measured. To 

 determine the degree of porosity place a little soil in a test 

 tube with three times its bulk of water. Shake well and 

 allow it to settle. The rough grains of sand and gravel fall 

 to the bottom, and then the fine grains of sand ; the clay comes 

 down in a fine state of division and forms a layer above the 

 sand, while humus or vegetable matter floats on the surface. 

 From the proportion of sand and clay the degree of porosity 

 can be determined sufficiently accurately for all practical 

 purposes, the more sand there is the more porous being the 

 soil. To decide whether much lime is present pour a few 

 drops of dilute hydrochloric acid on to a little soil ; if there 

 is a distinct effervescence lime is present. 



