KEFOET OF THE CHEMIST. 1.43 



Water, dctermiued at 100= C 7.100 



Carbouaceoiis matter G. 964 



Humus, soluble iu a solution of carbouato of soda 1. G73 



Insoluble bumus, (extracted by caustic potassa) 0. 213 



Sesquioxides of iron and aluminium l-l. 096 



Phosphoric acid 0. 206 



Alkalies, (potassa and soda) 0. 740 



Insoluble silica 63. 070 



Oxide of manganese 2. 072 



Lime 3. 166 



Loss 0.700 



100. 000 



The first observable feature in this table is the entire absence of sul- 

 phuric acid, or any other of the sulphur compounds. Next to this is 

 the large per cent, of humus, which, in the fresh soil, most probably 

 exists as humic acid in combination vrith alumina and iron, forming- 

 insoluble humates of these bases, which v\'ill account for the very small 

 amount of soluble matter in the soil. In a clay subsoil, charged with 

 water to the point of saturation for at least a portion of the year, the 

 organic matter which it contains will be converted into humic acid, 

 instead of undergoing the usual decomposition into carbonic acid, am- 

 monia, and water, which a free exposure to the air will effect. This 

 explains, also, the fact that crops which draw their nutriment from the 

 soU by superficial roots are not unfavorably aflected in these spots, the 

 surface-soil being more exposed to the air aud less subject to saturation.' 

 Liebig,in his Laws of Husbandry, (page 91,) alluding to this character of 

 soils, says : " Upon deep-rooting plants, such as turnips, clover, sainfoin, 

 X)eas, and beans, organic matters, accumulating largely in the subsoil, 

 act very injuriously, especially in clay, where they decay much more 

 slowly than in lime soil. * * * All these processes, however obscure 

 in themselves, are put an end to by applying lime to such a field." 



What this soil needs is, 1st, a thorough underdrainage which will relieve 

 the subsoil from saturation during the rainy months, and permit the air to 

 circulate freely through it at all times. The soft limestones of the cre- 

 taceous and tertiary formations give a substratum for the soil almost 

 absolutely impervious to water. These strata lying nearly horizontal, 

 as they do generally in Texas, will necessarily have depressions on their 

 surface, forming basins which will retain the water, and saturate the sub- 

 soil, till evaporation relieves it.. 2d. After the subsoil has been relieved 

 from saturation by uuderdrains, it should be broken with a subsoil- 

 plow so as to bring it more fully under the influence of the air. Sub- 

 soiling, however, will be of no value unless there is first a good under- 

 drainage ; for the rain, saturating the subsoil, will run it into a mass, and 

 its adhesive quality will make it as compact and as impervious to the 

 air as it was before it was broken. 3d. A heavy dressing of quicklime, 

 deeply plowed iu, would take up and neiitralize a large amount of humic 

 acid, and thus relieve other elements of plant-food which arc now locked 

 up as insoluble humates. But without underdrainage the effect of lime 

 will at best be but temporary; for lime on a saturated subsoil tends to 

 render it ultimately more compact aud impervious. Gypsum will greatly 

 improve these soils by furnishing sulphuric acid, an indisi)ensable ele- 

 ment of plant-food iu which they are very deficient. We would 

 therefore prescribe for these poison-soils, Ist. Thorough under- 

 drainage; 2d. Subsoil breaking; 3d. A heavy dressing of lime and 

 gypsum. 



