1 



234 Topogra])hj, Scenery, Geology, ^c. 



but none of the rock remains: it may probably have been slate or 

 serpentine. Specimens perfectly similar were sent out to America 

 some years ago by the Rev. John Campbell, English missionary in 

 Africa. The veins appear firm, but they are easily slivered by a 

 knife, and then the fibrous structure appears delicate as that of the 

 asclepias syriaca, or milk weed. There is also marked with the 

 same No. (9.) a superb piece of prehnite, of a deep emerald green,, 

 and the surface crystallized in the usual form. It will be remembered 

 that Col. Prehn, after whom this mineral is called, first obtained it 

 at the Cape of Good Hope, but we cannot say whether it was from 

 the same locality with this specimen.] 



10. Stones given me by a Hottentot from the Roggeveld. The 

 large one, as large originally as the two hands when extended ; she 

 was very reluctant to give it up, saying that it was " her book. 

 The other she brought to me as a present, saying, " it was gold. 

 The former are said to be abundant in the Karroo. [The specimen 

 taken by the Hottentot for gold, is simply fine grained mica slate, 

 with bright spangles of yellow mica, often taken for gold by people 

 better informed on other subjects than Hottentots. The piece which 

 the Hottentot woman called her book, greatly resembles Basanite 

 or touch stone. It is gashed or cut, apparently by art, in innumera- 

 ble directions, and on all sides, except where it appears to have been 

 broken off from the larger mass.] 



11 and 12. Specimens from different strata I met with in ascend- 

 ing the mountain near Tullagh, which led into the above named nV- 

 -er Karroo, and from the top of which the land extends off an almost 

 level plain to the north and east. [This appears to be a rock ot 

 granular quartz.] 



13. Translucent pebbles, siliceous, stalactltic, &c., from the 

 Great Orange River, six or seven hundred miles from this. i^'S 

 river stretches almost across South Africa, and may be compared o 

 the string, while the ocean boundary will represent the wood part o 

 the Bushman's bow. [These are very beautiful fragments of chal- 

 cedony and agate, evidently rounded by friction in water ; the colors 

 are dehcate shades of grey, blue and white. It is probable that the 

 place whence they came abounds in similar things, and might aiior 

 fine subjects for the lapidary. It is not unlikely that these things in- 

 dicate a region of trap rocks, in which they were formed, and irom 

 •which they were detached.] 





