156 KtmSERIES. 



ARTICLE 1. 



WEAK MANURES. 



The most commonly available weak manures are (1) clay, (2) 

 lime, (3) marls (4) fine saud, (5) wood-ash, (6) charcoal, (7) 

 surkhi-ash, (8) vegetable mould and (9) weak composts. 



1. CLAYS. Under this head we may include also loams and the 

 ooze and crust of fine earth found at the bottoms of tanks and stag- 

 nant pools. These and the true clays correct the want of consistence 

 and hygroscopicity of sandy soils and render them cooler, besides 

 preventing manurial matters from being carried away beyond the 

 reach of the young plants by subsoil drainage. In the case of light 

 soils full of organic remains, an admixture of clay, besides giving 

 them better consistence, prevents the two energetic action of the 

 organic matters, which are retained by the clay and yielded up to 

 the plants only in proportion to their requirements. 



2. LIME. Quicklime, used as a top-dressing, is applied with 

 great advantage to new soils containing a large quantity of un- 

 decomposed or only partially decomposed organic substances, which 

 it rapidly reduces, thereby forming carbonic acid, ammonia, phos- 

 phates, and other useful compounds. Such are peaty grounds and 

 recently broken up grass-lands, and also soils that have been for 

 some time treated with farmyard manure and vegetable mould. 

 Lime acts beneficially on the soil also by decomposing inert com- 

 pounds of soda and potash, which it thus releases for the use of 

 plants. Lastly, besides being itself an important element of plant 

 food, it loosens the texture of stiff clays and gives a certain amount 

 of cohesion to loose sands. 



3. MARLS. These have the same physical effect as the clays, 

 except that they produce warmer soils. Containing a large quan- 

 tity of lime, they exert, to a considerable extent, the same beneficial 

 influences as lime. 



4. FINE SAND. This is added to a stiff clayey soil to diminish 

 its compactness and to increase its capacity for heat. Silt is the 

 best adapted for the purpose on acount of the smallness of the 

 grains of sand of which it is composed, and also because it general- 

 ly contains some nutritive organic and mineral matters. Calcare- 

 ous sand is obviously preferable to a purely silicious sand. 



5. WOOD-ASH. Wood-ash forms an excellent manure, con- 

 taining, as it does, a very large proportion of potash and soda and 

 a considerable quantity of phosphates and sulphates. But it is 

 too expensive a manure to be used separately, and it is, therefore, 



