130 Account of Barren Island in [April, 



here presents. I should not suppose that these masses were thrown 

 from the volcano ; as in that case, it appeared to me they would 

 have been agglutinated together when in a state of fusion from intense 

 heat, and also fixed to the surface. The impression on my mind at 

 the time was, that some faint convulsion of the earth had elevated 

 them directly from below. Along this dark tract there was no ashes, 

 nor any thing indeed but the rock itself. On reaching the base of 

 the cone, I casually picked up the specimen No. 2. Here viewing 

 it, I judged the elevation to be half a mile to the top ; but in my 

 estimation of distances I do not pretend to be even near the truth. 

 It sloped so suddenly from about halfway up to the top of the 

 cone, that I considered it next to impossible to climb to the mouth- 

 We ascended however 30 or 40 yards, sinking ancle-deep in ashes, 

 at each slip, and I here took up the specimens Nos. 3 and 4, and 

 the other two smaller pieces. I did not bring away any specimen 

 of the ashes, but the color exactly resembles that of No. 3. In the 

 whole of our ramble, we did not meet with a spot capable of yielding 

 any vegetation, with exception of the withered grass formerly alluded 

 to : nor, although we looked anxiously for fresh water among 

 the rocks, could we perceive the smallest signs of it. The geogra- 

 phical site of the Island as given by Horsburgh seems perfectly 

 correct ; at least it agreed with my observations. The shore is 

 extremely steep, and a ship may almost rub her side against the rock. 

 Close in shore we could observe either tides or currents setting on 

 eddies round some of the points ; and in pulling from where we first 

 endeavoured to land, to where we did land, we were in ripplings." 



On examining the specimen No. 1, it is evident that it must have 

 undergone the action of fire ; and notwithstanding the above opinion to 

 the contrary, it has in all probability been ejected from the crater of 

 the volcano. On this point indeed we have positive evidence, as Cap- 

 tain Blair, in Col. Colebrooke's description, declares he saw these masses 

 thrown out from the volcano in a state of ignition, " many of which 

 rolled down the cone, while they were close to it, and bounded a 

 considerable way beyond them." The black scoria seems to derive 

 its color from an impregnating iron ; it contains minute crystals and 

 grains of felspar. The specimen No. 2, resembles the former, but 

 has been thrown from the volcano at an earlier period, and exhibits 

 the contained crystals in a state of decomposition. No. 3 is a very 

 compact lava, containing embedded in its substance distinctly crystal- 

 lized basaltic hornblende. No. 4, though vesicular, is more compact 

 than the two first varieties. Besides the felspar, it contains some dark- 

 colored crystals, the nature of which I have not fully ascertained. 



