36 Revietcs — Prof. Hull on Building Stones, etc. 



classification of the crystalline and other rocks, with short descriptive 

 characters of each. The author adopts the views of Durocher and 

 Bunsen, rather than that of Zirkel, for the division of the plutooic 

 and volcanic rocks, according to the proportions of silica they con- 

 tain, viz. into acid or highly silicated, and basic or less silicated 

 rocks ; the former comprising granite, syenite, quartz -porphyry, 

 felstone, trachyte, phonolite, pitchstone; the latter, or basic, in- 

 cluding porphyrite, diorite, melaphyre, diabase, basalt, dolerite, etc. 



The succeeding parts ii. to v. contain the Grranitic, Porphyritic, 

 Greenstone, and Serpentinous rocks, followed by parts vi. to xiii. 

 on Marbles, Alabaster, the Calcareous and Sandstone groups, the 

 volcanic building stones, slates, with one on the rarer ornamental 

 stones, as Fluor spar. Malachite, and the Quartz group. Under 

 each division a great variety of useful and interesting information 

 is given, with regard to their distribution in the British Isles, 

 Europe, and other countries, as well as the architectural and orna- 

 mental, uses to which they have been and may be applied. Among 

 the more interesting chapters are those devoted to the marbles and 

 limestones, which, from their great variety in colour, pattern, and 

 structure, are amongst the most beautiful rock productions in nature ; 

 and from their being found in many formations, and widely distri- 

 buted, have been largely used in ancient and modern times, both in 

 this country and on the Continent. 



The concluding observations in the work are devoted to the 

 physical and chemical characters of building stones, the mode of 

 determining them for general purposes, and their selection with 

 special regard to climate, either dry or humid, or the nature of the 

 atmosphere, whether pure, smoky, or acid, followed by a table con- 

 structed by Mr. C. H. Smith, showing the weights of a cubic foot 

 of specimens fairly representing all the varieties of building stones 

 used in this country and their localities, to which might have been 

 added the cohesive stre^gth, specific gravity, and absorbent power, 

 as is shown at p. 46 of the Commissioners' Eeport. 



Some few exceptions can be taken to the general character of the 

 book. Here and there certain omissions occur, or fuller details are 

 not given, which however may have been intentionally omitted, such 

 as the great variety and number of the Devonian and other newer 

 marbles and limestones of the Pyrenees, some of which were known 

 to the Eomans, worked at St. Gaudens, Luchon and other places, 

 and exported to this country and America ; the Eocene limestones of 

 the Isle of Wight used in the ecclesiastical buildings of the southern 

 counties, and the Lower a-nd Middle Eocene siliceous sandstones 

 (Sarsen stones), of which Kit's Coty House, Stonehenge, etc., are 

 constructed, and to which geologic period belong the Hampden 

 stone used about Aylesbury. Opinions may differ as to the position 

 of the limestones referred to the Great Oolite of Ancaster, Ketton 

 (^KHton, pp. 210-327), Casterten, and Barnack, which have con- 

 tributed so largely to the beauty of the numerous churches and 

 mediasval structures of Lincolnshire, Ely, Cambridgeshire, and 

 Northamptonshire, and which are now being chiefly used for the 



