Notices of Memoirs — Dr. Jolinston-Lavis on Vesuvius. 515 



size of a man's body, was clothed with the most glistening white 

 lining, and from the roof and walls showers of crystals fell from 

 time to time. These were not visibly red-hot in bright diffused 

 daylight, but looking towards the shaded inner extremity of the 

 cavity, a bright red incandescence was visible. In a short time, with 

 suitable apparatus, I collected over two kilogrammes of this material 

 absolutely free from mechanical impurities. 



Along many of the cracks of the lava beautiful glassy crusts of 

 halite, more or less impure, were formed, and often showed a dull 

 red heat in daylight. These crusts on being removed become 

 rapidly opaque and milky in hue, and audibly cracked into starch- 

 like columns, due to the rapid contraction on cooling — producing, in 

 fact, a miniature basaltic structure. 



About February 5th, 1894, the lava was issuing in very small 

 quantity, and by the 7th showed no trace of movement. Yet even 

 in May cracks in the lava near its point of exit were incandescent 

 some distance in, and the saline incrustations mentioned above were 

 in full perfection. 



Coincident with the arrest of the lateral outflow, the lava rose in 

 the chimney, and the red reflection from the top of Vesuvius that 

 had been absent for so long, with rare exceptions, was again almost 

 daily visible. The level of the lava in the main chimney soon rose to 

 the bottom of the new crater that had been forming, and increasing 

 in size during the time the lateral issue of lava had been going on, 

 and commenced the filling up of that cavity by the formation of a 

 cone of eruption, so that almost coincident with the arrest of the 

 leakage of lava laterally the central activity changed from the crater- 

 and dust-forming stage to the lava cake- and cone-forming stage. 



I made a careful examination of the summit of Vesuvius about 

 the middle of May. The crater in an east and west direction was 

 about 150 m. in diameter, and its depth, then decreasing, was 

 about the same. The walls were remarkably steep, in some places 

 even vertical or overhanging. The bottom could be seen with diffi- 

 culty owing to the crumbling nature of the edges. The walls are 

 nearly all covered by sublimates or dust that has adhered and crusted 

 them over, so that several dykes, both solid and hollow, can no longer 

 be distinguished. This is especially the case with the one formed 

 during the 1891 outburst. The details of the great rift of the 

 1880-81 and subsequent eruptions on the east side of the great 

 cone were still easily discernible. On the south side, and a little 

 to the east, a wall of rock stands out from the side of the crater 

 and is directed nearly towards the centre. It is capped by a pinnacle 

 of rock, and is really the old dyke of the 1885 eruption. 



Just to the east of that wall, and partly owing to its existence, 

 the slope of the inside of the crater is less in that direction. Here 

 the guides had made a little path for a few metres down. On ex- 

 amining carefully the condition of things from its lower termination, 

 which so far aided little the view of what was going on at the crater- 

 bottom, 1 found that by extending it down a slope, and then cutting 

 a ledge farther round to the east at a suitable point, a bracket-like 



