Geology of Southern India. 195 



tion."* Could an analogous observation to this, on the aggre- 

 gation of the constituents of minerals in a state of igneous 

 fluidity be obtained, a most important light would be 

 thrown on their occurrence in detached and massive por- 

 tions in rocks of igneous origin. In the present, as in 

 many other instances, geology must claim this boon from 

 the sister science of chemistry. 



At Mallepandy, a village about ten or twelve miles from 

 Kisnagherry, a beautiful specimen of epidote, of the usual 

 dark green colour, was found imbedded in a mass of true 

 granite, which was here observed, though not to any consi- 

 derable extent. The sienite was found to be peculiarly 

 large grained, and the crystals both of the hornblende and 

 felspar distinctly defined ; on one fragment of the rock, 

 which had been precipitated from the higher ground, a large 

 quantity of iron pyrites in cubical crystals was observed. 

 The country between this village and Wanianabaddy presents 

 the same general features, veins of porphyry outcrop at 

 about a mile from the latter place, exhibiting occasionally 

 small nests of chlorite. The road in many places passes 

 over the underlying granite, which is more abundant here 

 than usual, and the large quantity of mica scattered over its 

 surface causes it to glitter in the light of the sun like bur- 

 nished silver. Many water-worn fragments of different rocks, 

 greenstone, basalt, compact and vescicular, reddish coloured 

 sienite, so small grained as readily to be mistaken for sand- 

 stone, are found strewed over the sandy plain surrounding 

 Wanianabaddy. They are brought most probably from the 

 distant hills by the Palar river, which during the monsoon 



* Note. Will carbonate of lime treated as above with alumina segregate 

 similarly to silex ? If it does, then may not the occurrence of layers of nodular 

 kunkar in clay be explained on the same principle as the occurrence of like 

 layers of flint in chalk ? The question admits of an experimental reply, and 

 an effort to obtain this is now in progress. R. B. S. 



2d 



