36 On the Red Marl Formation of Mysore. 



taining embedded rounded pebbles, but I believe this to be 

 generally almost superficial, and to be probably a recent 

 aggregation of the debris washed from the surface. 



The surface yields easily to the native plough, and 

 produces crops of Raggy, Iwaree, and Cholum without 

 irrigation, but generally the upper part which has been 

 disintegrated by cultivation is so superficial, that an exten- 

 sive surface may sometimes be seen where the soil has been 

 entirely washed ofF by the heavy rains, leaving the bare 

 naked original rock, bearing on it the crossed scratches or 

 small channels produced by the point of the plough. 



It is remarkable that in this formation both kunkur and 

 carbonate of soda are almost unknown, while from the soil 

 in the hollows, muriate of soda, mixed with muriate of lime, 

 are commonly found, and the separation of the muriate of 

 soda is a manufacture of considerable extent. 



The depth of the red marl is very various, sometimes be- 

 ing more than thirty feet, while at others it is not more 

 than two or three, and in other parts the red marl is alto- 

 gether wanting, the coarse white kaolin* which universally 

 underlies it appearing at the surface. 



By sections in the nullahs it appears that this formation 

 is universally underlaid by a continuous bed of granite, 

 which appears also to have an undulating surface, for at 

 various points it protrudes in the shape of smooth, i-ounded 

 masses, sometimes of great magnitude, as at Nundydroog. 



* The author here uses the term kaolin, and from his accurate know- 

 ledge of the constituents of rocks he is doubtless perfectly right. We 

 have however availed ourselves of the discretion he has kindly intrusted 

 to us, of suggesting the term "porcelain clay," which is the same thing, 

 while the term is much better understood by the generality of readers 

 in almost every sense. As the improvement of Pottery in India is now 

 becoming an object of public interest, Captain Campbell, in the course 

 of his valuable researches may be able to point out the best variety 

 of the clay in question, for this important purpose. — Ed. Cal. Journ. 

 Nat. Hist. 



