SCIENTIFIC NEWS. CI 



the air. Many conftru&ions made with this cement afford the 

 mod complete proof of its folidity and tenacity. The detail 

 of thefe experiments are given in a report prefented by Le 

 Sage to the fociety of Agriculture, Commerce and Arts, at 

 Boulogne. Thefe muft no doubt be of much local import- 

 ance; but the analyfis of Guyton, as it tends (o elucidate the 

 composition of cements, is of more extended confequence. 



The fpecific gravity was between 2,04 to 2,19 and 10 

 grammes, or about -J- of an ounce produced ,in cente- 

 grammes. 



Lime - - - 403 



Carbonic acid * - - 330 



Clay - - - 187 



Oxide of iron 70 



Alumine ... 5 



995 



The 187 centegrammes of clay .afforded, 



Silica ; .... 99 



Alumine - - • • 39 



Oxide of iron - - m 43 



181 



The ftones are therefore compofed of 



Lime - . - 403 



Carbonic acid * - 330 



Oxide of iron - - - 113 



Silica ... 99 



Alumine - 4^ 



Lofs - *. - • n 



1000 



Citizen Guyton (hewed a veflel to the fociety d 'Encou- 

 ragement at Paris, which was very clofe and firm in its tex- 

 ture, whence the abridger in the bulletin des Sciences, from 

 which I take this article, exprefles his opinion that it woujd 

 prove very ufeful in the fabrication of various articles of 

 pottery. 



Not 



