AND THE NEIGHBOURING ISLANDS. 



161 



The granite is more compact and finer grained, as if compressed by the 

 quartz rock, while in a semifluid state. Veins of red granite, and bed-like 

 masses of it are observed in the neighbourhood, (No. 21). In the old 

 stockade on the north side, we saw a rolled mass of primitive greenstone, 

 (No. 25.), probably part of the ballast of some vessel, as none like it is to 

 be found in situ, near Pinang. 



VI. Pulo Jerajah is the largest and loftiest of the islands round 

 Pinang, from the east coast of which it is distant about three-quarters of 

 a mile. It is about two and a half miles in length, and nearly a mile in 

 breadth at its broadest part. Its greatest height is at its north end, 

 where the hill is between three hundred and four hundred feet above the 

 level of the sea. It is entirely composed of fine grey granite, with a small 

 proportion of mica, and is of no interest in a geological point of view. The 

 soil is a fine red clay, and the trees grow to a great height, with remark- 

 ably luxuriant foliage. 



VII. Pulo Kra. Two islands close to the main land of the 3Ialayan 

 peninsula, near Batta Kawang, are so named : they are separated from 

 each other by a narrow channel: each is about a mile long, and about 

 four hundred yards in breadth, rather lofty and thickly covered with wood. 

 Their creoloirical structure resembles that of Saddle island, above described, 

 distant from them fully thirteen miles, with Pulo Rimau, of granite for- 

 mation, between them. The principal rock of the northernmost, Pulo Kra, 

 is a kind of argillaceous schist, which is of a laminar structure, and 

 disposed in strata dipping at an angle of about forty-five degrees to the 

 south-east ; traversed by veins of quartz, with a crust apparently of metal- 

 lic matter running down in long black perpendicular lines along the face 

 of the rock, occasionally crossing each other 

 in a net-work fashion ; thus — 

 It is of various colours and consistence, pro- 

 bably as it has been more or less subjected to 

 the action of the weather. It is sometimes 

 greyish white, (Nos. 27, 2H, and 31.) sometimes 

 reddish, (No. .')().) sometimes blue, more or 

 less deep, Nos. 20 and 29). Every where it presents the laminar 



2 s 



