Feb. 26, 1880] 



NATURE 



401 



anchored opposite the castle. The town, although fairly 

 clean and flourishing, affords wretched accommodation to 

 the traveller. We lived almost entirely on hard boiled 

 eggs and sweet malvasia wine ; even fish, butter, and 

 milk could only be obtained at uncertain intervals, and 

 breakfast had to be delayed because no bread was baked. 

 It reminded me, indeed, forcibly of some of the out-of-the- 

 way towns on the flanks of Aetna, such as Aderno, 

 Randazzo, and Bronte. 



Lipari is about ten and a half square miles in area. 

 The highest point is 1,97s feet above the sea. Every- 

 where the island betrays its volcanic origin. Tuff, 

 pumice, liparite (quartz-trachyte), and obsidian, are 

 constantly met with ; at San Calogero a hot spring 

 (198 F.) pours forth water charged with carbonic acid 

 and sulphuretted hydrogen, while the Bagno Secco dis- 

 charges steam, sulphurous acid, and (it is said, but I 

 think the statement requires confirmation) hydrochloric 



acid. The latter is rarely evolved from fumeroles dis- 

 connected with an active volcanic vent, as in the present 

 case. 



Vulcano is undoubtedly the most interesting member of 

 the group from a volcanic point of view. It lies between 

 four and five miles to the south of Lipari, and contains a 

 semi-active crater, which, as regards its usual dynamic 

 : activity, occupies a mean position between Vesuvius in its 

 present state of action, and an actual solfatara like that of 

 Puzzuoli. We landed at the Porto di Levante (/), and at 

 once made our way to the house of the manager of the 

 chemical works near the Faraglioni (g ). The greater part of 

 the island, including the crater, has lately been bought 

 by a Scotch firm, and chemical works have been estab- 

 lished near the base of the crater. The manager's house 

 is the only house on the island ; the workmen live in 

 caves in the sides of the Faraglioni, and usually go to 

 Lipari on Sundays to hear Mass and to see their friends. 



Sketch of the great central cone of Vulcano, with Vulcanello in the foreground, a a. outer crater-rings, culminating in Monte Saraceno; o, highest point 

 of central cope; c, great crater; d, small crater, called the Fossa Antica ; ^.obsidian lava-stream of 1775 ;//, road leading into the crater; g, the 

 Faraglioni. with the chemical works near it ; k, Vulcanello, showing two of its craters : i, the Atrio between the outer crater-rings and the central 

 cone ; *, the lava-stream proceeding from Vulcanello; /, Porto di Levante ; m, Porto di Ponente. (Taken by permission of Prof. J. W. Judd and 

 Dr. Henry « oodward, from the Geological Magazine, December vol ii ) 



Sulphur, alum, and boracic acid are the substances pro- 

 cured from the crater. We noticed also sublimates of 

 sulphide of arsenic, and salts of copper were found in 

 association with some of the aluminous incrustations ; 

 also chloride of ammonium. I have been assured by two 

 eye-witnesses that blue and green flames sometimes issue 

 from clefts in the bottom of the crater. The former 

 would of course be due to burning sulphur ; might not 

 the latter owe their colour to the boracic acid? 



Prof. A. Cossa {Gasetta Chimica Italiana, 1S78, p. 

 235-246) has pointed out that Vulcano furnishes the 

 richest supply known of caesium and rubidium. The 

 Faraglioni, also called rocca dell' alume, is a trachytic 

 mass much decomposed by sulphurous and sulphuric 

 acids ; potassium-alum is found in its cavities, associated 

 with the sulphates of aluminium and calcium, with 

 chloride of ammonium, and with the alums of thallium, 

 caesium, and rubidium. Iron and copper compounds are 

 also found in small quantities in the incrustations, also 



the sulphides of selenium and arsenicum, and traces of 

 sulphate of lithium. The most complex mixture of vol- 

 canic products hitherto found was discovered by Cossa 

 on the edges of a small fumerole at the bottom of 

 the crater of Vulcano. It was found to consist of the 

 sulphides of arsenic and selenium, chloride of ammo- 

 nium, boracic acid, sulphate of lithium, together with 

 caesium- and thallium-alums, and traces of the alums of 

 potassium and rubidium. To the south-west of the 

 Faraglioni there is a well containing about half a metre of 

 water through which bubbles of gas are continually and 

 rapidly rising. C. Sainte Claire Deville calls this la 

 Grotta del Cane dell' /sola di Vulcano. The gas analysed 

 by Cossa was found to consist of So per cent, of carbonic 

 anhydride, 194 of nitrogen, and o - 6 of oxygen. The 

 temperature of the water is 22° C. 



We ascended the crater of Vulcano by the zigzag path 

 // and on arriving at the summit we found beneath us a 

 very regularly formed crater (<\ which is nearly one-third 



