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THE GEOLOGIST. 



the Lias having undergone the action of fire, and of that formation being the sepulchre 

 of the Wealden Iguanodon : with these and other glaring instances of carelessness 

 before us, we must say, that, far from making it easy, it is, we think, making 

 geology very hard for even a geologist to understand. Still a book of the 

 sort this assumes to be is wanted, and the idea was good. Our sincere advice to 

 the author is to get some competent Geologist to revise the facts, and to pay 

 more attention to the grammatical rales and requirements of the English 

 language, and then we can assure him he will find no one more ready than 

 ourselves to promote the sale of his little book. But in justice to those readers 

 who trust to our judgment and advice, we cannot recommend this edition. 



The Canadian Naturalist and Geologist. Vol. ii., No. 4, Sept., 1857. 

 This interesting number contains an account of the eleventh meeting of the 

 American Association for the Advancement of Science. 



Papers were read before the section of Natural History and Geology, by Mr. 

 Snell, "On the quantitative assay of chromium by the blow-pipe ;" by Prof. Dawson 

 " On some curious flexures in the Broad-top coal-strata of Pennsylvania attributed 

 to lateral pressure ;" and one by Sir. W. E. Logan " On the great series of Canadian 

 metamorphosed rocks," which the author of this paper had named respectively the 

 Huronian and Laurentian series of Canada. This is a paper worthy of perusal by 

 those who take part in the present sub-silurian enquiry, and the tracing out of 

 the remnants of that oldest world whose fragments are being found among the 

 so-called azoic rocks, and driving that term bit by bit out of its geological territory. 

 The Huronian rocks, according to Sir William, are often nearly vertical, and 

 are disposed unconformably under the Silurian Formation, the lowest strata of 

 which are made up of the debris of these unquestionably older rocks. 



Papers were also read by Mr. J. Sterry Hunt " On the origin of magnesian rocks ; " 

 by Prof. G. H. Cook " On the subsidence of the land on the sea-coasts of New 

 Jersey and the adjoining States ;" and by Mr. Hunt "On the metamorphism of sedi- 

 mentary rocks." 



The two interesting letters on the crystalline rocks of the North Highlands of 

 Scotland by our own eminent geologist, Sir R. I. Murchison, with notes on 

 their fossils by Mr. Salter, have made the Americans partially acquainted with 

 the subject of Sir Roderick's last communication to the Geological Society on the 

 metamorphism of the Scotch Silurian strata. 



Among the other valuable papers which our space will not permit us to 

 notice at length, are those by Professor Silliman " On the dressing of metallic 

 ores;" Sir W. E. Logan "On the subdivision of the Laurentian rocks of 

 Canada into two great groups characterized by the presence of much lime or by 

 the comparative absence of that mineral compound ;" Prof. Chapman " On the deposi- 

 tion of native metals in vein-fissures by electro-chemical agency, and on the 

 saltness of the sea ;" Prof. Dawson " On newer pliocene fossils of the St. Lawrence 

 Valley ;" Prof. Ramsay " On the succession of fossils in British rocks ;" Prof. Pierce 

 " On the formation of continents ;" Prof. Guyot " On the physical geography of 

 Africa;" Prof. Hall "On the direction of the currents of deposition and source 

 of materials of the older Paleozoic rocks ;" and Prof. Swallow " On the geological 

 survey of the Missouri, &c." Many of the papers in the other sections of the 

 Association, and some of the extraneous articles in this number of the Magazine, 

 are not without interest to the geologist. 



