56& BURNT CLAY. 



texture is changed. In its natural state it is so adhesive, that 

 air cannot get into it, nor water out of it. It also offers great 

 mechanical opposition to the. passage of roots through its viscid 

 mass, and hence it is exclusively inhabited by a coarse and 

 worthless vegetation. Burning changes all this ; the particles 

 of clay lose their adhesiveness, and this alone gives a new 

 character ,to the soil, which offers freedom to the entrance 

 of air and exit of water, and which crumbles readily away 

 beneath the advancing roots of a soft and succulent race of 

 plants. Such changes are in themselves most important ; but 

 this is not aU the difference between burnt and unburnt clay. 

 The roots of plants, which were before unable to decay, are 

 reduced by fire to their saline constituents, and so enrich the 

 land. And, moreover, the burnt particles of clay acquire the 

 power of absorbing ammonia from the air, and holding it within 

 their pores till showers fall and wash it into the land, where it 

 immediately acts as a nourishing food to the crops. 



Mr. W. Paul, of Cheshunt, says, " It lias .been the custom here for 

 some years, in spring, when the operations of pruning, &c. are ended, 

 instead of suffering the rough branches to lie about, presenting an 

 untidy appearance, to collect them in a heap, and build a waU. of turf 

 round them in a semicircular form, about three feet high. They are 

 then set fire to, and when about half burnt down, such weeds and other 

 rubbish as collect in every garden, and will not readily decompose, are 

 thrown on the top, and earth is gradually cast up as the fire breaks 

 through. During the first two or three days no ordinary care is requi- 

 site to keep the pile on fire, but after this, if the fire is not allowed 

 to break through and thus expend itself, it will certainly spread 

 through the whole heap, and almost any amount of soU may be burnt 

 by still adding to the top. The soil we burn is the stiffest loam that 

 can be found within our limits, and is rather of a clayey nature ; also 

 turf from the sides of ditches and ponds, in itself naturally sour and 

 full of rank weeds. The clay thus burnt has been found beneficial in 

 every instance. In black garden mould, where Peach-trees were dis- 

 posed to sucker and oanker, despite of animal manures and drainage, 

 two or three annual dressings of burnt earth appear so to have altered 

 the soil that they now grow clean, vigorous, and healthy, are free from 

 suckers, and produce roots completely matted with fibre. The like 

 success has attended its application to other fruit-trees. During the 

 summer of 1842, six beds of Tea-scented Roses, growing in an alluvial 

 loam (the adjacent fields are of the same soil, and grow large crops of 



