120 Reviews — Pahnleri and Mallet on Vesuvius. 



I. — The Eruption of Vesuvius in 1872. By Professor Luigi 

 Palmieei, Director of the Vesuvian Observatory. With Notes 

 and an Introductory Sketch of Terrestrial Yulcanicity, etc., by 

 Egbert Mallet, Mem. Inst. C. E., F.E.S., F.G.S., etc. With 

 Illustrations. Imp. 8vo. pp. 148. (London : Asher & Co., 1873.) 



AS the particles of ashes, sand, and gravel contribute with the 

 scoriiB and lava to build up the cone of Vesuvius, so, by the 

 aid of larger type and leaded lines. Prof. Palmieri's modest little 

 pamphlet on the eruption of 1872 has been built up into 58 pages, 

 over which the translator has poured forth 78 pages of his own ideas 

 and theories by way of introduction, concluding with a substratum 

 of eight pages of notes. 



We do not wish it to be supposed for a moment that we under- 

 value the almost heroic labours of Prof. Palmieri, as with patient 

 care and untiring attention, he watches and records the varying 

 indications of volcanic energy, denoted by the seismograph and 

 electrometer, in his Observatory on the Crocelle, a part of the old 

 buttress-wall of Somma, by Vesuvius, even, as on the terrible 

 night of the 26th of April, 1872, when " the Observatory lay between 

 two torrents of fire, which emitted an insufferable heat," so that 

 " the glass in the window-frames, especially on the Vetrana side, was 

 hot and cracking, and a smell of scorching was perceptible in the 

 rooms." (p. 90.) 



Prof. Palmieri's report furnishes many very interesting details not 

 heretofore recorded. For example, the very diverse characters of the 

 lavas of 1871 and 1872. The former (1871) is characterized by 

 Prof. Palmieri as a " lava with a united surface." Mineralogically 

 it is " rich in leucite, and containing little or no pyroxene." The 

 latter (1872) is described as a "lava whose surface breaks up on 

 cooling, into fragmentary scoriae ; " its constitution shows it to be 

 "poor in leucite and rich in pyroxene." 



It is certainly remarkable that lavas so very different, both in 

 mineral constitution and external aspect, should have flowed out of 

 the same volcano within a few months of each other. Such rapid 

 changes in the products of the same vent prove incontestably the 

 great amount of change, both mineralogical and chemical, that is 

 continually going on in the subtex'ranean laboratory at no great 

 distance from its outward opening. 



" These (1872) lavas (says Palmieri) carried along in their course 

 a quantity of scoriae which had long been subjected to the action of 

 the acids of the fumaroles close to the craters ; and also many bombs 

 — round masses similar to those ejected from craters — some having a 

 diameter of 4 to 5 metres. These bombs must have flowed out with 

 the lava, for they are found through its whole course, and masses so 

 enormous were not tlirown up from the craters during tlie eruption ; 

 those lying on the cone near the craters seldom exceeding a deci- 

 metre in diameter." (p. lOo.) 



This also is a singular and not very intelligible fact. Volcanic 



