of Salem and Barramahal. 155 



his system of geology do not apply perfectly to that of 

 India, and in many points is at variance with Indian ob- 

 servations. Dr. Boase's primary geology is very useful, and 

 is the best we have ; but that also, for many reasons, does not 

 perfectly apply to India. 



In drawing up the following descriptive account of the 

 granite of this district, all the accessible works of authors 

 (excepting the costly volumes of the Geological Society, 

 which are a sealed book to most persons in India,) have been 

 consulted and digested; and such geological and mineralo- 

 gical terms have been adopted as appeared least objection- 

 able. It has been impossible to append to all the terms 

 made use of accurate definitions and considerations of the 

 propriety of their use ; because, if this had been done, the 

 paper would have been a treatise on petrology, instead of a 

 descriptive account. As an instance, the term syenite may 

 be misunderstood, which is here made use of, not as applied 

 to a granitic rock, but to a speckled granular aggregation of 

 hornblende with some felspar and quartz, which definition 

 will agree with Jameson's, if its application to a granitic rock 

 is excluded. 



General appearance of Granite. 



The general appearance of granite is very variable, and I 

 think it probable that it will be found that its outward 

 form is connected with its mineralogical composition and 

 mode of aggregation. 



Dr. Christie's description appears well adapted to the 

 granite of the Barramahal ; he remarks : " Rugged hills with 

 " bold denticulated outlines lie heaped together in the 

 " greatest irregularity, or occasionally form an obscure ridge, 

 " the crest of which, when interposed between the spectator 

 " and the evening or morning sun, presents the most fan- 

 " tastic forms. Some of these ridges, when their dark 

 " outline is seen at twilight against a ruddy western sky, 

 " emulate in their varied forms the capricious shapes of 



