214 JOURNAL, R.A.S. (CEYLON). [VOL. II., PART II. 



Nuwara Eliya. Quartz, if deeply impregnated with oxide 

 of iron, will also moulder away, but not quite so soon as the 

 other mineral constituents of hypogene rocks. 



Before I had observed the immense lithomargic hills of 

 Uva and Nuwara Eliya, it was difficult for me to believe 

 that large mountain masses of hard rock could disintegrate 

 so completely into lithomarge. When there are, however, 

 such unequivocal proofs of rocks, several hundred feet high, 

 mouldering away into kaolin or white procelain clay in some 

 parts, and in others into lithomargic earths and clays of 

 various colours and consistence, it is not difficult to account 

 even for the formation of the harder forms of laterite. In 

 sections made in Nuwara Eliya for the construction of roads, 

 successive layers of sienitic gneiss are seen in various stages 

 of decomposition, and these layers retain in some parts, 

 where the decay is not far advanced, the original lines of 

 stratification. Some of these layers are of pure kaolin, 

 others of a reddish or yellowish clay; some mixed of all three, 

 giving a beautiful variegated surface to these exposed parts 

 of the hills. In half-decomposed portions of some of the 

 hills on the plains of Nuwara Eliya may be seen dark red- 

 dish spots, which are formed of decomposed garnets, and in 

 other hills are seen scaly graphite. Adularia and ceylonite 

 are sometimes found in the beds of clay. If such then be 

 the striking illustration of the decomposition of one form 

 of gneiss in which hornblende and felspar prevail, it is easy 

 to conceive other forms of granitic or gneissic rocks weather- 

 ing into laterite in other circumstances and other situations. 

 Laterite in any shape is not found in Nuwara Eliya. The 

 stones used here for building are half-decomposed gneiss 

 obtained from lithomargic hills, and it is yet to be 

 ascertained how long these will last. I fear that the 

 decomposed stone is too felspathic to last many years. 



The presence of lignite in some of the laterites of Southern 



