316 Notes, chiefly Geological, [No. 172. 



covered with their angular and rust-stained fragments. Glimmering 

 hornblende rock, veined with milky quartz, and a pale flesh-coloured 

 felspar alternate with the gneiss. The outgoings of two or three dykes 

 of basaltic greenstone are passed on the roadside. The surface of the 

 country from Seringapatam gradually rises as it approaches the ghauts. 



Periapatam. — This place is twenty-five miles westerly from Hus- 

 sairpore, and forty-three miles from Seringapatam. It stands on the 

 rise of the western ghauts from the table lands of Mysore, on the 

 frontier of the wild territory of Coorg. To the west the scenery is 

 mountainous and clothed with forest ; fifteen miles to the north rises 

 Bettadapore to the supposed height of 6,000 feet, one of the loftiest 

 summits of this part of the western ghauts : the elevation of Periapatam, 

 barometrically calculated, is 4,000 feet above the sea's level. 



The country between Hussairpore and the ghauts is a succession of 

 rocky risings and falls of the surface, covered for the most part with 

 reddish alluvial soil, over the face of which are scattered numberless 

 angular fragments of the surrounding rocks ; especially white and 

 iron-stained quartz, and occasionally kunker. Some of these alluvia 

 have not travelled far, since we often find the colour of the surface 

 soil a true index to the nature of the rock beneath : viz. dark-red or 

 coffee-coloured soil over hornblende rock and trap; light-red to sandy 

 soil over gneiss and granite ; light greenish-grey over talc-schist, and 

 white, or what is nearly white, over felspar and quartz rocks. 



The quartz beds, being usually harder than their neighbours, are 

 written in white bas-relief characters over the face of the country. 

 They never weather — like the felspars, hornblendes, and micaceous 

 rocks — into clay, but usually break up into fragments by imperceptible 

 fissures, into which water, impregnated with iron from the surrounding 

 weathered rocks, soon insinuates itself and stains the rock. At length 

 the particles, composing the fragments themselves, lose their cohesion, 

 and break up into an angular gritty sand. 



In the low grounds, intervening between the rocky swells, is a black 

 or dark-coloured mould, which I should hesitate to call regur. It ap- 

 pears to me to be the result, first of vegetation produced by water rest- 

 ing there (like the oases of the desert), and finally of artificial culture, 

 manuring, &c. 



In these vallies flourish groves of palms and wild dates ; and here 

 the ryot carries on his simple process of cultivation. 



