Note on Chapter XII. 



In this Chapter (XII.) Mr. Blanford has very fully entered on the discussion of the cha- 

 racter and distribution of the recent deposits of the districts he has visited. These views 

 I do not desire at the present, either to support with additional evidence, or to gainsay, 

 although there is nauch which might be urged, but I think it just to others who have also 

 examined these districts, to state that in many respects their views differ from those of 

 Mr. Blanford. Omitting any question of how far the tenn ' soil' may be justly applicable to 

 many of the deposits described above, my own examination of a large part of these districts 

 and the investigations of others in the same and other portions, lead us to think that very 

 much larger areas than are spoken of above, are covered with soils (?) or deposits which are 

 solely the results of the local decomposition of the underlying rocks. This appears unquestion- 

 ably the case with a very large part of the Cuddalore sandstone country. 



The non-fertile character of what is called ' regiu-' in Trichinopoly is noticed. I would here 

 desire to express a caution against the very lax use of this term ' regm-' or ' cotton soil,' which 

 appUes it indiscriminately to all clays which have even a tendency to a blackish colour. 

 Clays varying in the amount of their organic matter from 1 per cent, to 12 or 14 per cent, ; 

 in the amount of their lime from 2 to 17 per cent. ; in then- colour from a deep black to a 

 sandy grey, and in their texture from a fine and strongly adhesive clay to an earthy sand, have 

 been all set down as ' cotton soil' or ' regur,' although their origin must have been different, and 

 their agricultural capabilities essentially distinct. 



There is, too, as it seems to me, too hasty and too locally based, a generalization, in stating 

 that this ' regur' occurs always in the lower portion (relatively) of any given part of the 

 country. In many cases where I have noticed that it does occur in these relative depressions, 

 the fact appears simply due to the washing off of the previously existing thin coat of regur fi-om 

 the higher ridges, by the ordinary pluvial action of the country : thus exposing the red soil 

 beneath. This red soil is far more universally spread out under the regur than is allowed above. 



That the ' lal' or red sandy soil and the regur are both aqueous deposits is clear to any 

 one who looks at them, and I am not aware that any doubt on this point has existed. But 

 it appears to be a very unnecessary restriction or limitation of the source or cause of the forma- 

 tion of such deposits, to speak of them as only the result of lagoon or salt-lake action. 

 Black soil of this kind is in course of every-day formation in every jheel or marsh in the coimtry, 

 at the distance of hundreds of miles fr'om the actual sea, as well as close by. And there seems 

 no reason whatever to suppose that the same processes of formation or deposition have not 

 been in operation long before the surface of the country had entirely assiuned its present foim. 



I think it equally certain that neither the black mud at the bottom of jheels nor the 

 deposits in lagoons, would exhibit any remarkable resemblance to the typical characters of 

 regur, until after these muds had been exposed to subajrial influences for a considerable time. 



Much of what is above (Chap. XII.) referred to as * lal' is what by other wiiters has been 

 called laterite. Another instance of the diflSculty of getting rid of a lax use of a very 

 indefinite term if once adopted. — T. Oldhasi. 



I 



