362 jMmoviTrfo^oa »oiw. 



Observations If I am ask^d liow to improve a certain field, I should 



and enquiries . ■,. , , • ■, , , . , , . , 



respecting the"! immediately wish to ascertain what is the nature of itg 



improvement soil; in which kind of earth it is deficient: and in what it 

 of poor soils. , , 



superabounds. 



If it be all clay, its proportion of chalk and sand must 

 be added; and, v/here these cannot be had, substitutes 

 may perhaps be found: stiff clay soil is made more open, 

 in some countries, by burning portions of it in heaps, and 

 then ploughing the hardened earth into the land. 



If the soil be sand, a frequent source of barrenness in 

 different parts of Suffolk (where I have seen Whole acres 

 of barley blown away,) then clay becomes useful, and 

 marl the best possible ingredient*. 



An ingenious man, having obtained a grant of some 

 waste sandy land, which, till then, had been wholly un, 

 occupied, was allowed to enclose as much as he could 

 cultivate. He found near the foot of a hill a stratum of 

 clay, with which he covered, the first year, an acre of 

 sand, and then sowed it with grass seeds; this succeeding, 

 he followed up his plan year after year, till he formed a 

 complete surface of grass on many acres, — which, ploughed 

 up last year, produced hira nine quarters of oats per acre. 

 Thus laud, which, but seven years ago, would not have 

 jnaintained a single sheep, became fertile, and of consider- 

 able value t. 



These premises being granted, and the facts established 

 on the authority of many and repeated experiments; let us 

 see, if any theory can be formed to account for the cir- 

 cumstance, why a mixture of the earths should be neces- 

 sary for the purposes of agriculture. 



The changes which take place iu combustion, and those 

 ch'anges which constitute or exhibit animal and vegetable 

 life, have often been compared: Food which supports fire, 

 (as oxygen) is well known to contribute to the support of 



* Common marl contains from 66 to 80 parts of pure chalk ; 

 the remainder- is in various proportions pure earth of alum and 

 siiex, Kirnuan. 



t This system, on a much larger scale, has been pursued by one 

 of the most intelligent farmers in Suffolk, Mr. Rodwell, for M'hich 

 W obtained a medal from the Bath Agricultural Society. 



life ; 



