274 Description of a Grotto at the Cape of Good Hope. 



the South Chamber and Vander-West-huissen's Chamber is so 

 narrow as scarcely to admit a large person, and is called Botha's 

 Poort or door, likewise Nel's Poort, is equally narrow between 

 Vander-West-huissen's and Thorn's Chamber. These apartments 

 constitute the whole of this very extensive scries of subterraneous 

 caverns ; and should there be any other apartments, they must 

 communicate by a very small passage, as I narrowly examined 

 every part. The beauty of some of the chambers cannot be de- 

 scribed. The production of the stalactites is very surprising ; 

 a single drop of water from the roof, in time will raise a column 

 50 feet high. A great many drops have produced cauliflowers, 

 pulpits, and other beautiful and romantic festoons, shewing the 

 remarkable action of water, and carbonic acid upon calcareous 

 rock. The Bath-house contains several basins of clear water. 

 Innumerable quantities of bats have taken up their residence here, 

 (apparently from the excrement,) from time immemorial — they are 

 the only inhabitants of these lonely regions. The heat is great, 

 and even oppressive at the farthest extremity. Had this beautiful 

 grotto been situated where it was more accessible to mankind, 

 and not so far in the wilds of a desert country, we should ere this 

 time have seen a proper account of it, by which means it would 

 have been plucked from the obscurity which shrouds it at present, 

 and have gratified the eyes of the curious, and the lovers of the 

 sublime. 



Art. XL On some undescribed Minerals. By H. J. A. 

 Brooke, Esq., F.R.S. 



Cliildrenite. 



About four years since I purchased at Tavistock, id Devon- 

 shire, three specimens of a mineral, said to have been taken from 

 some part of the ground which had been perforated for the canal 

 lately completed there. They were supposed to be carbonate of 

 iron, but it was obvious on looking at the crystals that they must 

 belong to some other substance. 



Intervening occupations prevented me for a long time from ex- 



