Revieics — 0. F. RodwelVs Etna. 521 



verticillate arrangement of the fruit, and of what I believe to be the 

 leaves {Aster ophjllites or Sj)henophjlluin) , constitute no difficulty 

 preventing us from accepting this conclusion. Brongniart long ago 

 pointed how commonly a verticillate foliage occurred amongst living 

 Lycopods." Figures of this interesting form are given (pi. 64, figs. 

 23-27), and also of Peronosjporites, figs. 28-38. J. M. 



II. — Etna : A History of the Mountain and its Eruptions. By 

 G. F. KoDWELL. With Maps and Illustrations. (0. Kegan 

 Paul & Co., 1881.) 



THE Memoir on Mount Etna, or Monte Gibello, which Mr. Eodwell 

 reprints from the Encyclopcedia Britannica, contains little that is 

 new. He refers to the writings of Lord Winchelsea, Sir William 

 Hamilton, and Patrick Brydone, and the later works of Elie de 

 Beaumont and of Sartorius von Waltershausen, the latter being 

 undoubtedly the finest and most exhaustive work on the volcano. 

 Etna is about the grandest natural object to be met with in Europe ; 

 as was pointed out by the late Prof. Jukes, we should have to put 

 Snowdon on Ben Nevis, and Carrantuohill, the highest pealc in 

 Ireland, on the summit of both to make a mountain like Etna. 

 There are two cities, Catania and Aci Eeale, and sixty-two towns or 

 villages on its slopes. By reason of the wonderful fertilit}'- of the 

 soil and the healthiness of the climate, it is far more thickly popu- 

 lated than any other part of Sicily or Italy ; more than 300,000 

 persons live on its sides; the population of the habitable zone of 

 Etna amounts to 1424 per square mile. Even Lancashire, the most 

 populous county in Great Britain (of course excepting Middlesex), 

 and the possessor of two cities which also furnish more than a 

 million inhabitants, has a population of only 1479 to the square mile. 

 The minor craters round the centre cone are to be counted by 

 hundreds. The account of the ascent, and the stay on the way at 

 the Casa Inglesi, is much like that which we have all read in daily 

 papers or weekly journals. The summit was reached just before 

 sunrise, and Mr. Eodwell had the good fortune to see the projection 

 of the triangular shadow of the mountain across the island, a hundred 

 miles away. The shadow appeared vertically suspended in space at 

 or beyond Palermo, and resting on a slightly misty atmosphere ; it 

 gradually sank until it reached the surface of the island, and as the 

 sun rose it approached nearer and nearer to the base of the mountain. 

 The more purely scientific part of this memoir does not appear to be 

 strong; "hydrochloric acid," he writes, "is said to frequently issue 

 from the crater." The snow which falls on the mountain is stowed 

 away in caves and used by the Sicilians during summer. A ship 

 load is also sent to Malta, and the Archbishop of Catania derives a 

 good deal of his income from the sale of Etna snow. During the 

 descent the apparent nearness of the minor cones and of the villages 

 at the base of the mountain strikes the observer. They appear to be 

 painted on a vertical wall, and although from ten to fifteen miles 

 distant, seem to be almost within a stone's throw. This is the efl'ect 



