226 On Manures. 



be made, between burning it into ashes, and merely torre- 

 fying it. When thoroughly burnt, the whole texture of the 

 soil is destroyed, and clay is reduced into a species of dried 

 earth, divested of all soluble matter, and which can only act 

 mechanically on the soil. But when clay is merely torrefied, 

 or scorched, the staple of the soil is but little reduced ; and as 

 it is during that process, that the clay acquires fertilizing pro- 

 perties, it is evident, that the more slowly it is carried on, the 

 better will be the manure produced. 



5. Sea-ooze, or Warp. This substance abounds at the mouths 

 of friths, estuaries or arms of the sea, and of the rivers which 

 run into them. It is of a most enriching nature, and adds to 

 the staple of the soil. It is used as a top-dressing in spring, 

 for crops both of grain and grass, more especially for the lat- 

 ter. It is an excellent material for composts, particularly for 

 thin soils. The late public-spirited Duke of Bridgewater, 

 between the years 1790 and 1800, made considerable use of 

 sea-ooze, brought up from the Mersey, in barges, by his ca- 

 nal, to lands near Worsley. It promotes the improvement 

 of garden soils in a manner hardly to be credited ; and wheat 

 or oats, manured with sea-ooze, are little subject to rust, mil- 

 dew, or any other disorder ( Z45 ) 



6. Canal, Pond, or River Mud. This article is not of equal 

 use in every instance, as much of its quality depends upon the 

 substances with which it is mixed. Where the water is re- 

 sorted to by cattle, or water-fowl, or receives the washings of 

 towns, houses, farm-yards, &c. or the immediate drainage of 

 large tracts ( Z4<s ), it is richer, and will prove valuable, in what- 

 ever way it is managed ( a47 ). It must at any rate add to the 

 staple of the soil with which it is mixed, and bring with it 

 some useful ingredients. In the Netherlands, it is found by 

 the gardeners of Ghent, that the mud of canals and rivers is 

 much improved in its quality, when it is exposed, in small 

 heaps, to a winter's frost, and a summer's sun, before it is 

 used. This proves how much the success of agriculture de- 

 pends upon rninuticB. For the same substance, which, if mixed 

 with the soil, immediately after being taken up, might be of 

 little or no use, may, when properly prepared, be highly con- 

 ducive to fertility. 



7. Road Scrapings The mud raked and shovelled from the 

 public roads, may, with great advantage, be used as an in- 

 gredient for forming composts, particularly for clay soils. 

 Where the stones of which the roads were made, consist of 

 limestone, such a compost is singularly useful. In particular 

 instances it is even more economical, to purchase road scrap- 



