222 



Statistical Heport on the 



[No. S5, 



constructed of this stone, in great use among the native drug- 

 gists. 



Quartz veins also occur, varying in thickness from a rupee to 

 several feet — the superior hardness and durability of the quartz 

 causes it to appear as a ridge in the sienite. 



Hard as the sienite and gneiss are, there are few rocks more 

 subject to disintegration and decay, and to consequent change ; of 

 these three are particularly well marked. 



1st. The ochreous degeneration — where the horneblende be- 

 comes decomposed, and a red, or more generally, a yellow ochre is 

 produced. The appearance put on by these rocks while undergo- 

 ing this change so nearly approximates to that of sandstone, that 

 from a hand specimen an experienced observer even might be de- 

 ceived regarding the real characters of the rock — but from this 

 error he would be freed by breaking it, when a nucleus of the 

 original rock would be discovered, surrounded by decomposing 

 layers of ochreous matter. 



2d. The steatitic degeneration — for such it is according to the 

 opinion of some G-erman mineralogists, who regard it as a change 

 analogous to the adipocere of animal matter — happens at a vil- 

 lage called Dummenapilly in the Vizianuggur pergunnah, where 

 it is mined and shaped into pots and cups by the blacksmiths. 

 The rock at the surface is gneiss with horneblende and mica for 

 two of its ingredients, and much less steatitic than what is found at 

 some depth — so much so as to render it unfit for being cut into 

 vessels — (can the pot stone of Mysore mentioned by Buchanan be 

 this rock ?) but it differs in its lithologic character from that 

 mineral. Pencils for school boys are manufactured from it, and also 

 lings for the use of the Lingayets around Warungul. 



3d. The mohrum, in which felspar would seem to be originally 

 the predominant rock — it is frequently cut by veins of disintegrat- 

 ed limestone, and nodules of hard limestone are also found in it : 

 may not the lime have acted as a powerful agent in forwarding the 

 decomposition by the formation of neutral salts ? 



^. ^^^^^ Oxygenerated iron ore, sp. gravity 4-3 to 



4'8, giving an average of 4*5, extensively found 

 and worked. 



2d. Titaniferous iron ore, sparingly found and not worked — a 

 specimen in my possession was dug up in sinking a well at Hun- 

 numcondah in the soft mohrum. 



