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LXII. Notices respecting New Books, 



Mat&iaux de Construction de V Exposition Universelle de 1855. Par 



A. Delesse. Paris, 1856. Pages 420. 

 'T^HIS is a valuable report on the building materials of all kinds, 

 ■■- whether natural or artificial, which were displayed at the Paris 

 Exhibition. M. Delesse was peculiarly qualified to undertake the 

 task of drawing up this report, from his intimate acquaintance both 

 with geology and chemistry, and from his former researches on the 

 chemical composition of rocks. The report contains the results of a 

 large number of chemical analyses, as well as of experiments on the 

 strength and other physical properties of the materials exhibited. 

 We may refer particularly to the chapters on marbles and cements, 

 as containing a large amount of novel and interesting information. 

 From the latter we extract the following observations on the cements 

 of Canada. 



Thorold Cement. — ^This cement, from Thorold near St. Catherine 

 in Upper Canada, is prepared by calcining an argillaceous limestone 

 of the Upper Silurian formation. The limestone is grayish-black, 

 and emits an argillaceous odour when breathed on ; but the cement 

 itself has a yellow colour. The specimen examined did not effer- 

 vesce with acids, and contained only 3*37 per cent, of water. It 

 set in fifteen minutes with a disengagement of heat. A specimen 

 immersed in water ten minutes after being moistened, set under the 

 water, and presented finally the same cohesion as another specimen 

 which was not immersed till two hours after it had set. The resist- 

 ance to traction of this cement was about 0'85 kil. It was found to 

 consist of — 



Lime 53-55 



Magnesia 2*20 



Silica 29-88 



Alumina and peroxide of iron .... 12' 70 

 Sulphate of lime 1*58 



Quebec Cement. — At Quebec in Lower Canada, a limestone belong- 

 ing to the Inferior Silurian is quarried for the purpose of making 

 cement. The rock which yields it was discovered by Captain Bad- 

 deley of the Royal Engineers. It is an argillaceous, compact lime- 

 stone, destitute of fossils, and strongly coloured by carbonaceous 

 matter. The cement itself was yellow, and effervesced feebly with 

 acids ; it lost, when heated, 11*6 per cent, water and carbonic acid. 

 It set at the end of twenty-six minutes. The resulting mass was not 

 so hard as that from the Thorold cement. Its resistance to traction 

 was about 0*49 kil. Its composition was as follows : — 



Lime 52*49 



Magnesia traces 



Silica 27-401 3Q.^g 



Alumina and oxide of iron 12-66 j 



Sulphate of lime , 7*95 



j 42-58 



