534 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



cement of great beauty and hardness is obtained with soluble 

 glass and chalk alone. 3 A, July 29, 1871, 70. 



IMPROVED GLYCERINE CEMENT. 



A cement of great value for many purposes, and capable 

 of being used where resistance to both the action of water 

 and to that of heat is required, is composed by mixing ordi- 

 nary glycerine with dry litharge, so as to constitute a tough 

 paste. For uniting the joints of steam pipes and other sim- 

 ilar applications, this preparation is said to be very satisfac- 

 tory. 1 J3, November 12, 1871, 95. 



TENACIOUS CEMENT. 



A cement of great tenacity, and possessing the qualities 

 of being colorless and transparent, and capable of fastening 

 wood, paper, porcelain, glass, marble, alabaster, and stone, 

 when not exposed either to moisture or a high degree of heat, 

 is prepared by mixing together two parts of nitrate of lime, 

 twenty-five of water, and twenty of powdered gum arabic, 

 and rubbing them well together in a mortar. The nitrate 

 of lime is prepared by placing small fragments of white mar- 

 ble in 25 per cent, of nitric acid, allowing a slight excess of 

 the marble, then heating and filtering it. The solution con- 

 tains 33^ per cent, of the nitrate. In using this cement the 

 fractured surfaces are simply to be united and held together 

 by wrapping a cord tightly around them. The operation of 

 drying is completed in from one to four days, according to 

 the state of the atmosphere. 15 (7, xin., 304. 



CEMENT TO RESIST SULPHURIC ACID. 



A cement to resist sulphuric acid, it is reported, may be 

 made by melting caoutchouc by a gentle heat, and adding 

 from 6 to 8 per cent, of the weight of tallow, keeping the 

 whole well stirred. Then mix in enough dry slacked lime to 

 make the whole of the consistency of soft paste, and finally 

 add 20 per cent, of red lead, whereby the mass, which would 

 otherwise remain soft, becomes hard and dry. This cement, 

 it is asserted, resists boiling sulphuric acid. A solution of 

 caoutchouc in twice its weight of raw linseed oil, aided by 

 heating, and the addition of an equal weight of pipe-clay, 

 yields a plastic mass which also resists most acids. 1 -1, 

 October 20, 1871, 194. 



