THE SOURCE OF THE NILE. 187 



The porphyry fliews itfelf by a line purple fand, without 

 any glofs or glitter on it, and is exceedingly agreeable to the 

 eye. It is mixed with the native white land, and fixed gra- 

 vel of the plains. Green unvariegated marble, is generally 

 feen in the fame mountain with the porphyry. Where the 

 two veins meet, the marble is for fome inches brittle, but 

 the porphyry of the fame hardnefs as in other places. 



The granite is covered with fand, and looks like flone of a 

 dirty, brown colour. But this is only the change and impref- 

 fion the fun and weather have made upon it; for, upon break- 

 ing it, you fee it is grey granite, with black fpots, with a red- 

 difh caft, or blufh over it. This red feems to fade and fuf- 

 fer from the outward air, but, upon working or polifhing 

 the furface, this colour again appears. It is in greater 

 quantity than the porphyry, and nearer the Red Sea. Pom- 

 pey's pillar feems to have been from this quarry. 



Next to the granite, but never, as I obferved, joined with 

 it in the fame mountain, is the red marble. It is covered 

 'with fand of the fame colour, and looks as if the whole 

 mountain were fpread over with brick dull:. There is alfo 

 a red marble with white veins, which I have often i'cen at 

 Rome, but not in principal fubjedts, I have alfo i'e?n it in 

 Britain. The common green (called Serpentine) looks as if 

 covered over with Brazil muff. Joined with this green, I 

 faw two famples of that beautiful marble they call Ifabella; 

 one of them with a yellowifh caft, which we call Quaker* 

 colour ; the other with a blucifli, which is commonly termed 

 Dove-colour. Thefe two fecm to divide the refpective 

 mountains with the terpentine. In this green, likewife, it 

 Was we faw the vein of jafper ; but whether it was ahiblutc- 



A a 2 Xy 



