472 EEPORT OF NATIONAL MUSEUM, 1899. 



According to Dr. L. Sambon, as quoted by Dr. H. J. ,rohn.ston-Lavis: 



All the best pumice of commerce is obtained from the northeast region of the island 

 of Lipari, extending a.s far as the summit of Mte. S. Angelo on its northern slope. 

 * * * It is excavated at the Fossa Castagna near M. Pelato, at M. Chirica, and 

 on the shore of the Mosche. 



I visited a quarry of M. Pelato on the outer southern side. The height was about 

 1.50 m. and 1 m. large. The entrance was sustained by poles, faggot-s of brushwood, 

 and stones; at first one descended for 160 steps, then one ascended for about 50 m. 

 where two naked men were digging in the dull light of an oil lamp. In decending 

 I met some young men who were carrying up baskets full of pumice. They wore 

 short coarse linen drawers, and on their naked breast hung the blessed scapulary. 

 On my arrival at the workes they made me sit down on an empty basket while 

 I watched the men dig out the pieces of pumice, often the size of a human head, 

 from the embedding matrix, which is composed of different sized fragments and 

 dust of the same material, pressed together, and forming an incoherent tuff. 

 They told me of their poor wages, and the dangers of their work in con.sequence of 

 the frequent collapse of the workings, killing men and youths. It was horrible to 

 hear those accounts of misery and misfortune at the bottom of these caves. 



The low roof and narrow passage from which every moment fragments detached 

 themselves seemed to threaten the collapse of the whole; and it was with great relief 

 that I again reached the daylight. Only a few weeks previously a quarry of M. 

 Pelato had collapsed and buried some workmen, and more than two days work were 

 required to reach them. These unfortunate men, saved by a miracle, returned again 

 to their work, for what else could they have done to obtain bread? 



Prolonged and curious was at all times the discussion concerning the origin of 

 pumice. It was believed to be amianthus decomposed by fire, by Pott, Bergman 

 and Demeste; calcined lignite or schist, by Vallerio; scorified marl by Sage and 

 granite that had become blown up and fibrous by the effect of fire and water by 

 Dolomieu. The latter asserted having found inclosed in some pieces of pumice frag- 

 ments of granite. He also declares that he had seen masses of granite which took on 

 gradually the fibrous structure and other characters of pumice; so that he concluded 

 that granite or granitoid schist was the primitive material which by the effect of the 

 volcanic fire passed to the state of the pumice. Finally he declares he sent speci- 

 mens to all the most learned geologists of the time. Spallanzani, who visited that 

 same locality and hunted in every part of Campo Bianco in a most diligent manner 

 but without being successful in finding the granite of Dolomieu, says wittily that 

 probably the French geologist had carried them all away. Spallanzani himself, on 

 the contrary, considers that pumice and obsidian are the result of fusion of great 

 masses of intermediate lavas which one encounters on all parts of the mountain. 

 Prof. J. F. Blake recently, probably ignoring the observations of Spallanzani, is sat- 

 isfied in finding in that locality "Mother-pumice" as he has baptized it, from which 

 also is derived the obsidian. But pumice, obsidian and all intermediate rock varie- 

 ties more or less scoriaceous are but different forms of the same eruptive product. 

 The whole history and modifications of pumice have been worked out by Dr. John- 

 ston-Lavis, who has shown that by studying these eruptive products the w^hole 

 mechanism of volcanic action in general is explained and the sequence of eruptive 

 phenomena of any volcanic focus can be made out. * * * 



When we descend to the shore of the Beja delle pomice by the gorge to the South 

 East of the great obsidian flow, the slopes facing the lava are composed of immense 

 deposits of pumice in which hundreds of holes are observable, marking the excava- 

 tions made in search of the larger masses of this valuable rock, much of which could 

 be seen in the numerous baskets standing at hand. The sight of the enormous 



