Reviews — Murchison's " SiluriaJ 



SiLURiA. By Sir Koderick I. Murchison, Bart., K.C.B., etc., 

 etc. [Third Edition.] Fourth Edition, including the '' Silurian 

 System." With a map, much new matter, and many illustra- 

 tions. 8vo. 1867. 



AS its title-page explains, this work consists of " A History of the 

 Oldest Eocks in the British Isles and other countries ; with 

 sketches of the origin and distribution of native gold, the general 

 succession of geological formations, and changes of the earth's sur- 

 face," — subjects which, we all know, have long ranked high as 

 favourites among Sir Eoderick's many scientific researches, and have 

 had his earnest attention for many (some for nearly fifty) years. 

 Again, then, has this veteran geologist, coming to the front with 

 unabated energy and enlarged experience, applied his native acumen 

 and clear judgment, his knowledge of details and power of gene- 

 ralization, to describe and elucidate the older rock-formations — the 

 foundation-stones of half the globe, and to give the history of the 

 successive systems of primasval life, as shown by the Palgeozoic Eocks 

 and Fossils of Great Britain and many other parts of the world. 



Like all historians. Sir Eoderick has had to apply to others for 

 many data and for collateral information ; and this he has received 

 abundantly, and with justice fully acknowledged ; indeed, he has 

 taken pleasure in enumerating his helping friends and collaborateurs 

 in his Preface (where upwards of twenty are mentioned), and his 

 Index is rich with the names of authors and discoverers who have 

 been quoted or referred to in furtherance of his work. 



Furnished wiih the latest information from all sides, and enriched 

 with the results of his own labours during the last ten years, he has 

 carefully considered the rapidly accumulated facts and opinions re- 

 lating to palaeozoic geology, and has produced, as we might expect, 

 a most valuable digest of all that is known of Laurentian, Cambrian, 

 Silurian, Devonian, Carboniferous, and Permian Eocks and Fossils, — 

 well written, well printed, and well illustrated ; and supplemented, 

 moreover, with chapters on the geology of gold and the philosophy 

 of geology. 



In the previous edition of " Siluria," Sir Eoderick was enabled to 

 lead the geologist to a still lower stage in the rock-structure of the 

 British Islands than had been previously recognized, namely, to what 

 he then termed the "Fundamental Gneiss," which comes out at 

 Cape Wrath and the Lewis, and underlies the great Cambrian masses 

 of Eoss-shire (once thought to be '' Old Eed Conglomerate"), and the 

 superposed Silurian quartzites and schists of Assynt, which, though 

 disguised by metamorphism, were clearly recognised by the few 

 fossils in their scanty seams of limestone. In the present edition Sir 

 Eoderick gives us a still larger, and at the same time more intimate, 

 view of these oldest and lowest rock-masses, which, once muds, 

 sands, and reefs, have long since been changed into crystalline gneiss 

 and marble, and now constitute wide lands in North America and 

 elsewhere. Sir W. E. Logan and his associates in the Geological 



