REVIEWS GEOLOGICAL SURVEY OF CANADA. 321 



without allusion to the place of honor held by Canada in the great 

 exhibitions of London and Paris : a place, be it remembered, mainly 

 due to the merit of her mineral collections as developed by Sir "William 

 Logan and his able coadjutors. Owing to the pressure of extraneous 

 work, occasioned by the engagements of the Director of the Survey 

 in connexion with the more recent of these exhibitions, the Reports of 

 four years (1853-54-55-56) are published collectively in the present 

 volume. The Report for 1857, we are glad to learn, is already in the 

 printers' hands, and will shortly be issued. The goodly volume before 

 us, containing five hundred pages of closely printed matter, comprises 

 a long Report from Sir William Logan ; four Reports from Mr. Murray, 

 accompanied by a collection of large and carefully constructed maps ; 

 valuable Reports from Mr. Richardson and Mr. Billings ; and four Re- 

 ports of much interest from Mr. Hunt. 



• The report of Sir William Logan relates chiefly to the distribution 

 of the crystalline limestones in the Laurentian Rocks of Grenville, 

 Harrington, Wentworth, Chatham, and some adjacent townships. The 

 accurate delineation of these limestone bands is not only of importance 

 in an agricultural and economic point of view, but it is also of essen- 

 tial moment' in enabling us to obtain a correct knowledge of the struc- 

 tural peculiarities of Laurentian districts in general. As Sir William 

 observes, " the Laurentian rocks, stretching on the north side of the 

 St. Lawrence, from Labrador to Lake Superior, occupy by far the 

 larger share of Canada ; and they have been described in former Re- 

 ports as sedimentary deposits in an altered condition, consisting of 

 gneiss interstratified with important bands of crystalline limestone. 

 The gneiss proper, when it approaches the surface, yields but an in- 

 different soil, while the soil derived from the limestones, which are 

 usually in a disintegrated condition, is of a most fruitful description. 

 The farms which have been established on the Laurentian formation, 

 run almost wholly on the limestones and their associated strata, and 

 afford a pretty distinct proof that the distribution of these calcareous 

 bands being once known, it would not be difficult to determine in what 

 direction it would be most judicious to push settlement. It is also in 

 contact with these limestones, or near them, that the iron ores are 

 found, which so prominently characterise the Laurentian series, as 

 well as the lead-bearing veins belonging to it ; and as the limestones 

 possess external and internal characters which render them more con- 

 spicuously distinct from the gneiss than any of the component mem- 

 bers of the gneiss are from one another, they afford the least difficult 



