132 AMOUNT OF EAKTH CHAP. III. 



given time. We will begin with the first 

 method, as it was first followed. 



Near Maer Hall in Staffordshire, quick-lime 

 had been spread about the year 1827 thickly 

 over a field of good pasture-land, which had 

 not since been ploughed. Some square holes 

 were dug in this field in the beginning of 

 October 183*7 ; and the sections showed a 

 layer of turf, formed by the matted roots of 

 the grasses, J inch in thickness, beneath 

 which, at a depth of 2J inches (or 3 inches 

 from the surface), a layer of the lime in 

 powder or in small lumps could be distinctly 

 seen running all round the vertical sides of 

 the holes. The soil beneath the layer of 

 lime was either gravelly or of a coarse sandy 

 nature, and differed considerably in appear- 

 ance from the overlying dark-coloured fine 

 mould. Coal-cinders had been spread over 

 a part of this same field either in the year 

 1833 or 1834; and when the above holes 

 were dug, that is after an interval of 3 or 4 

 years, the rinders formed a line of black spots 

 round the holes, at a depth of 1 inch beneath 

 the surface, parallel to and above the white 

 layer of lime. Over another part of this field 



