1196 Nurmaor Chanderi Cotton. [No. 132. 



or the action of the elements : although the Vindhya mountains 

 abound in chasms from 300 to 800 feet in depth, and present on 

 the south a precipitous scarp of 1,500 feet; and the Nerbudda has 

 farther sapped into the rock some 800 feet, reckoning from the foot of 

 those mountains. The immediate deposit upon this rock in Nimar is 

 generally a deep bed of clay, mixed with lime, sand, and kankur. Oc- 

 casionally rotten sandstone prevails : and upon this stratum lies the 

 black soil generally found upon trap formations, though not peculiar 

 to such. This averages perhaps fifteen feet in depth near the river, 

 but is deepest when found on higher flats, having been less worn 

 by the elements. This black soil is generally supposed to be the 

 debris of the trap formation, and from thence to take its hue ; I con- 

 fess I doubt the correctness of this theory. Trap is colored wholly by 

 the black, or purer oxide of iron. It is decomposed by the absorption 

 of an additional volume of oxygen by the iron, which increasing its 

 mass, rends the rock into powder. In this condition, the color of the 

 trap is a rusty red, and incapable I think of giving that intensely 

 black dye to a soil composed of its particles. I speak under correc- 

 tion, having no means of analyzing the soil. But as a similar hue 

 occurs in soils resting upon granite and other formations, I have been 

 more disposed to ascribe it to the presence of carbon, than of iron. 

 It is singular that under this soil, the richest diamond mines 

 in the world are found. The fact, that a stratum of clay and kankur 

 is interposed between the trap rock and the black soils, seems to 

 countenance my theory, and the yearly destruction of the jungles in 

 Malwa by fire, would in the course of ages have supplied an abundance 

 of carbon. But if, as is said, this black soil form under the blowpipe, a 

 black glass, the theory can scarcely be maintained with any confidence.* 

 The natives prefer the blackest soil for all kinds of cotton, and in 

 fact, for every purpose. The other soils are all more or less impo- 



* The black cotton soil certainly owes its colour also to the protoxide of iron, and not 

 to carbonaceous matter. See Transactions of the Agricultural Society Vol. vi. p. 208, in 

 which are quoted three analyses of this soil from Bundelcund. It is possible that the 

 black soil may be owing to the decomposition of a kind of trap no longer existing, which 

 contained a greater proportion of alkali, (soda, or potash) than the present and more 

 enduring kinds of the rock, or it may have been an original volcanic product? or a 

 volcanic mud of a peculiar kind ? The question is one far too obscure and complicated 

 to be discussed in a note, and indeed to be discussed at all in the present state of 

 our knowledge. — H. P. 



