of the great Sicilian volcano. He opens with a history of the mountain, 
or rather of the knowledge of the mountain, then describes its physical 
features in detail, including in this category the peculiarities of distribution 
of animal and vegetable life upon its surface; gives an account of his 
experience of an ascent to the summit, which includes many useful hints for 
those who may desire to follow in his footsteps; and finally notices the 
various towns situated on the slopes of Etna itself, which are interesting in 
many respects, and appear to be in a flourishing and increasing condition. 
The fifth chapter contains a chronological account of the recorded eruptions 
of Etna, of which the author notes seventy-eight, the earliest in the time of 
Pythagoras, b.c. 525, the latest in 1874. The earlier traditions, which would 
carry back the activity of the mountain as far as the year 1226 b.c., are 
mentioned by Mr. Rodwell, but not regarded as sufficiently authentic to be 
relied on. In most cases, but especially with reference to the more violent 
eruptions, the phenomena manifested are briefly described. In the sixth 
chapter the author descants, briefly, as may be supposed, upon the geology 
and mineralogy of the great volcano, and here we find references to recent 
investigations by Professor Silvestri, and to the results of original researches, 
supplemented by an appendix by Mr. Erank Rutley on the microscopic 
characters of the lavas of b.c. 396 and a.d. 1535, 1603, and 1689. The con- 
stituents of these lavas are “ plagioclase, augite, olivine, magnetite, and, in 
some cases, sanidine — possibly titaniferous iron — and in some, if not in all, a 
slight residuum of glass ; ” and Mr. Rutley remarks upon the close similarity 
of structure presented by these lavas, the first and last of which are separated 
by an interval of more than 2,000 years. Drawings showing the micro- 
scopic structure of these two lavas are given. The other portions of the 
book are fully illustrated with drawings and maps, some of the latter 
coloured. 
SILURIAN EOSSILS OF GIRVAN.* 
T HROUGHOUT the South of Scotland, wherever fossiliferous rocks occur, 
they are so twisted and twirled about that the attempt to arrive at any 
definite conclusion as to their succession is a matter of no small difficulty. 
One of the best examples of this is to be found in Mr. Lapworth’s recent 
paper on the rocks of the Moffat district, the extreme complication of which 
could only be elucidated by years of work upon scattered exposures of beds 
containing graptolites. Still further west, in the district of Girvan, in Ayrshire, 
the Silurian rocks are almost equally confusing. Great masses of eruptive 
rocks have been pushed up through the sedimentary and metamorphic beds, 
and the latter have, in consequence, been thrown into several folds within 
the distance of a few miles. By the action of faults and of rivers cutting- 
down into these deposits the fossiliferous Silurian rocks are exposed here 
and there ; but the exposures are so unconnected that the correlation of the 
* “A Monograph of the Silurian Fossils of the Girvan District, in Ayr- 
shire.” By H. Alleyne Nicholson, M.D., &c., and Robert Etheridge, Jun., 
Fasciculus I. 8vo. London and Edinburgh : Blackwood & Sons, 1878. 
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