the minerals also give place to the cement until ihe whole mass 

 terminates below in a fine argillaceous substance, with an imper- 

 fect slaty structure and a spanish-brown aspect. 



This rock being much softer in its nature than the basalt and 

 more affected by decomposing agents, the number of fragments 

 are consequently greater in proportion, and much more finely pul- 

 verised, forming the little soil, which supports some of the scatter- 

 ed and scanty patches of the vegetation of these islands. 



The minerals embraced in this rock are generally confined to its 

 upper part where it unites and passes into the incumbent amygda- 

 loid, many of them are also in common with that rock. They consist 

 chiefly of quartz, crystalline and amorphous, amethyst, chalcedo- 

 ny, cachalong, agate, red jasper, felspar, zeolite, calcareous spar 

 in rhombic crystals, sulphate of barytes, a minute crystal resem- 

 bling black spinelle, sulphuret of iron and green carbonate of cop- 

 per. 



The only appearance of an organized remain that I any where 

 saw, was a fragment of carbonized wood imbedded in this con- 

 glomerate. It was in a vertical position, about two and a half feet 

 in length and four inches in diameter : its colour is black, exhib- 

 iting a tine ligneous structure, the concentric circles are distinctly 

 visible on its superior end, it occasionally gives sparks with steel, 

 and etlervesces slightly in nitric acid. 



There are a number of active volcanoes in the vicinity of these 

 islands, indications of which are daily seen in the pieces of pumice 

 found strewed along the beach. Capt. Weddel saw smoke issu- 

 ing from the fissures of Bridgeman's island, a few leagues to the 

 N. E. Palmers land, situated one degree south : what little is 

 known of it, which is only a small portion of its northern shore, con- 

 tains several. Deception island also, one of this group, has boil- 

 mg springs, and a whitish substance like melted felspar, exudes 

 from some of its fissures. 



The rocky fragments on these islands are generally very hard 

 and little liable to the disintegrating influence of the atmosphere, 

 and rarely indeed are they subject to a power capable of agitating 

 them sufficiently to remove even the acuteness of their angles, 

 consequently but a small quantity of soil can any where be found, 

 and when discovered, being destitute of the necessary ingredients 

 that give tatness to the earth elsewhere, it affords but a few scattered 

 patches of vegetation, which appear to struggle hard for the small 



