Chap. III. BROUGHT UP BY WORMS. 135 



long existed as poor pasture and was so 

 swampy that it trembled slightly when 

 stamped on, was thickly covered with red 

 sand so that the whole surface appeared at 

 first briglit red. When holes were dug in 

 this field after an interval of about 2|- years, 

 the sand formed a layer at a depth of | in. 

 beneath the surface. In 1842 (i.e., 7 years 

 after the sand had been laid on) fresh holes 

 were dug, and now the red sand formed a 

 distinct layer, 2 inches beneath the surface^ 

 or 1-J inch beneath the turf; so that on an 

 average, '21 inches of mould had been annu- 

 ally brought to the surface. Immediately 

 beneath the layer of red sand, the original 

 substratum of black sandy peat extended. 



A grass field, likewise not far from Maer 

 Hall, had formerly been thickly covered with 

 marl, and was then left for several years as 

 pasture; it was afterwards ploughed. A 

 friend had three trenches dug in this field 

 28 years after the application of the marl,* 



* This case is given in a postscript to my paper in the 

 ' Transact. Geolog. See' (Vol. r. p. 505), and contains a serious 

 error, as in the account received I mistook the figure 30 for 80. 

 The tenant, moreover, formerly said that he had marled the field 

 thirty years before, but was now positive that this was done in 

 10 



